| Message ID | 20200107090519.3231-3-cw00.choi@samsung.com (mailing list archive) |
|---|---|
| State | Rejected |
| Delegated to: | Chanwoo Choi |
| Headers | show |
| Series | PM / devfreq: Add debugfs support | expand |
Hello Chanwoo, 07.01.2020 12:05, Chanwoo Choi пишет: > Add new devfreq_transitions debugfs file to track the frequency transitions > of all devfreq devices for the simple profiling as following: > - /sys/kernel/debug/devfreq/devfreq_transitions > > And the user can decide the storage size (CONFIG_NR_DEVFREQ_TRANSITIONS) > in Kconfig in order to save the transition history. > > [Detailed description of each field of 'devfreq_transitions' debugfs file] > - time_ms : Change time of frequency transition. (unit: millisecond) > - dev_name : Device name of h/w. > - dev : Device name made by devfreq core. > - parent_dev : If devfreq device uses the passive governor, > show parent devfreq device name. > - load_% : If devfreq device uses the simple_ondemand governor, > load is used by governor whene deciding the new frequency. > (unit: percentage) > - old_freq_hz : Frequency before changing. (unit: hz) > - new_freq_hz : Frequency after changed. (unit: hz) > > [For example on Exynos5422-based Odroid-XU3 board] > $ cat /sys/kernel/debug/devfreq/devfreq_transitions > time_ms dev_name dev parent_dev load_% old_freq_hz new_freq_hz > ---------- ------------------------------ ---------- ---------- ---------- ------------ ------------ > 14600 soc:bus_noc devfreq2 devfreq1 0 100000000 67000000 > 14600 soc:bus_fsys_apb devfreq3 devfreq1 0 200000000 100000000 > 14600 soc:bus_fsys devfreq4 devfreq1 0 200000000 100000000 > 14600 soc:bus_fsys2 devfreq5 devfreq1 0 150000000 75000000 > 14602 soc:bus_mfc devfreq6 devfreq1 0 222000000 96000000 > 14602 soc:bus_gen devfreq7 devfreq1 0 267000000 89000000 > 14602 soc:bus_g2d devfreq9 devfreq1 0 300000000 84000000 > 14602 soc:bus_g2d_acp devfreq10 devfreq1 0 267000000 67000000 > 14602 soc:bus_jpeg devfreq11 devfreq1 0 300000000 75000000 > 14602 soc:bus_jpeg_apb devfreq12 devfreq1 0 167000000 84000000 > 14603 soc:bus_disp1_fimd devfreq13 devfreq1 0 200000000 120000000 > 14603 soc:bus_disp1 devfreq14 devfreq1 0 300000000 120000000 > 14606 soc:bus_gscl_scaler devfreq15 devfreq1 0 300000000 150000000 > 14606 soc:bus_mscl devfreq16 devfreq1 0 333000000 84000000 > 14608 soc:bus_wcore devfreq1 9 333000000 84000000 > 14783 10c20000.memory-controller devfreq0 35 825000000 633000000 > 15873 soc:bus_wcore devfreq1 41 84000000 400000000 > 15873 soc:bus_noc devfreq2 devfreq1 0 67000000 100000000 > [snip] > > Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> > --- > drivers/devfreq/Kconfig | 13 +++ > drivers/devfreq/devfreq.c | 126 +++++++++++++++++++++++++++++ > drivers/devfreq/governor.h | 3 + > drivers/devfreq/governor_passive.c | 2 + > include/linux/devfreq.h | 1 + > 5 files changed, 145 insertions(+) > > diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig > index 0b1df12e0f21..84936eec0ef9 100644 > --- a/drivers/devfreq/Kconfig > +++ b/drivers/devfreq/Kconfig > @@ -74,6 +74,19 @@ config DEVFREQ_GOV_PASSIVE > through sysfs entries. The passive governor recommends that > devfreq device uses the OPP table to get the frequency/voltage. > > +comment "DEVFREQ Debugging" > + > +config NR_DEVFREQ_TRANSITIONS > + int "Maximum storage size to save DEVFREQ Transitions (10-1000)" > + depends on DEBUG_FS > + range 10 1000 > + default "100" > + help > + Show the frequency transitions of all devfreq devices via > + '/sys/kernel/debug/devfreq/devfreq_transitions' for the simple > + profiling. It needs to decide the storage size to save transition > + history of all devfreq devices. > + > comment "DEVFREQ Drivers" > > config ARM_EXYNOS_BUS_DEVFREQ > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c > index c7f5e4e06420..7abaae06fa65 100644 > --- a/drivers/devfreq/devfreq.c > +++ b/drivers/devfreq/devfreq.c > @@ -268,6 +268,57 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq) > } > EXPORT_SYMBOL(devfreq_update_status); > +/** > + * devfreq_update_transitions() - Update frequency transitions for debugfs file > + * @devfreq: the devfreq instance > + * @old_freq: the previous frequency before changing the frequency > + * @new_freq: the new frequency after frequency is changed > + */ > +struct devfreq_transitions { > + struct devfreq *devfreq; > + struct devfreq_freqs freqs; > + unsigned long load; > +} debugfs_transitions[CONFIG_NR_DEVFREQ_TRANSITIONS]; > + > +static spinlock_t devfreq_debugfs_lock; This could be: static DEFINE_SPINLOCK(devfreq_debugfs_lock); and then spin_lock_init() isn't needed. Also, The "<linux/spinlock.h>" should be included directly by devfreq.c > +static int debugfs_transitions_index; > + > +void devfreq_update_transitions(struct devfreq *devfreq, > + unsigned long old_freq, unsigned long new_freq, > + unsigned long busy_time, unsigned long total_time) > +{ > + unsigned long load; > + int i; > + > + if (!devfreq_debugfs || !devfreq || (old_freq == new_freq)) > + return; > + > + spin_lock_nested(&devfreq_debugfs_lock, SINGLE_DEPTH_NESTING); > + > + i = debugfs_transitions_index; > + > + /* > + * Calculate the load and if load is larger than 100, > + * initialize to 100 because the unit of load is percentage. > + */ > + load = (total_time == 0 ? 0 : (100 * busy_time) / total_time); > + if (load > 100) > + load = 100; > + > + debugfs_transitions[i].devfreq = devfreq; > + debugfs_transitions[i].freqs.time = ktime_to_ms(ktime_get()); > + debugfs_transitions[i].freqs.old = old_freq; > + debugfs_transitions[i].freqs.new = new_freq; > + debugfs_transitions[i].load = load; > + > + if (++i == CONFIG_NR_DEVFREQ_TRANSITIONS) > + i = 0; > + debugfs_transitions_index = i; > + > + spin_unlock(&devfreq_debugfs_lock); > +} > +EXPORT_SYMBOL(devfreq_update_transitions); What about EXPORT_SYMBOL_GPL()? > /** > * find_devfreq_governor() - Find devfreq governor from name > * @name: name of the governor > @@ -401,6 +452,10 @@ static int set_target(struct devfreq *devfreq, > return err; > } > > + devfreq_update_transitions(devfreq, cur_freq, new_freq, > + devfreq->last_status.busy_time, > + devfreq->last_status.total_time); > + > freqs.new = new_freq; > notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE); > > @@ -1787,6 +1842,72 @@ static int devfreq_summary_show(struct seq_file *s, void *data) > } > DEFINE_SHOW_ATTRIBUTE(devfreq_summary); > > +/** > + * devfreq_transitions_show() - Show the frequency transitions of the registered > + * devfreq devices via 'devfreq_transitions' debugfs file. > + */ > +static int devfreq_transitions_show(struct seq_file *s, void *data) > +{ > + struct devfreq *devfreq = NULL; > + struct devfreq *p_devfreq = NULL; > + struct devfreq_freqs *freqs = NULL; > + unsigned long load; > + int i = debugfs_transitions_index; > + int count; > + > + seq_printf(s, "%-10s %-30s %-10s %-10s %-6s %-12s %-12s\n", > + "time_ms", > + "dev_name", > + "dev", > + "parent_dev", > + "load_%", > + "old_freq_hz", > + "new_freq_hz"); > + seq_printf(s, "%-10s %-30s %-10s %-10s %-6s %-12s %-12s\n", > + "----------", > + "------------------------------", > + "----------", > + "----------", > + "----------", > + "------------", > + "------------"); > + > + spin_lock(&devfreq_debugfs_lock);> + for (count = 0; count < CONFIG_NR_DEVFREQ_TRANSITIONS; count++) { > + devfreq = debugfs_transitions[i].devfreq; > + freqs = &debugfs_transitions[i].freqs; > + load = debugfs_transitions[i].load; > + > + i = (CONFIG_NR_DEVFREQ_TRANSITIONS == ++i) ? 0 : i; > + if (!devfreq) > + continue; > + > +#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE) > + if (!strncmp(devfreq->governor_name, > + DEVFREQ_GOV_PASSIVE, DEVFREQ_NAME_LEN)) { > + struct devfreq_passive_data *data = devfreq->data; > + > + if (data) > + p_devfreq = data->parent; > + } else { > + p_devfreq = NULL; > + } > +#endif > + seq_printf(s, "%-10lld %-30s %-10s %-10s %-6ld %-12ld %-12ld\n", > + freqs->time, > + dev_name(devfreq->dev.parent), > + dev_name(&devfreq->dev), > + p_devfreq ? dev_name(&p_devfreq->dev) : "", > + load, > + freqs->old, > + freqs->new); > + } > + spin_unlock(&devfreq_debugfs_lock); > + > + return 0; > +} > +DEFINE_SHOW_ATTRIBUTE(devfreq_transitions); > + > static int __init devfreq_init(void) > { > devfreq_class = class_create(THIS_MODULE, "devfreq"); > @@ -1808,9 +1929,14 @@ static int __init devfreq_init(void) > devfreq_debugfs = NULL; > pr_warn("%s: couldn't create debugfs dir\n", __FILE__); > } else { > + spin_lock_init(&devfreq_debugfs_lock); > + > debugfs_create_file("devfreq_summary", 0444, > devfreq_debugfs, NULL, > &devfreq_summary_fops); > + debugfs_create_file("devfreq_transitions", 0444, > + devfreq_debugfs, NULL, > + &devfreq_transitions_fops); > } > > return 0; > diff --git a/drivers/devfreq/governor.h b/drivers/devfreq/governor.h > index dc7533ccc3db..01eecfdaf2d6 100644 > --- a/drivers/devfreq/governor.h > +++ b/drivers/devfreq/governor.h > @@ -68,6 +68,9 @@ extern int devfreq_add_governor(struct devfreq_governor *governor); > extern int devfreq_remove_governor(struct devfreq_governor *governor); > > extern int devfreq_update_status(struct devfreq *devfreq, unsigned long freq); > +extern void devfreq_update_transitions(struct devfreq *devfreq, > + unsigned long old_freq, unsigned long new_freq, > + unsigned long busy_time, unsigned long total_time); The 'extern' attribute isn't needed for function prototypes defined in header files.
On Tue 07 Jan 01:05 PST 2020, Chanwoo Choi wrote: > Add new devfreq_transitions debugfs file to track the frequency transitions > of all devfreq devices for the simple profiling as following: > - /sys/kernel/debug/devfreq/devfreq_transitions > > And the user can decide the storage size (CONFIG_NR_DEVFREQ_TRANSITIONS) > in Kconfig in order to save the transition history. > > [Detailed description of each field of 'devfreq_transitions' debugfs file] > - time_ms : Change time of frequency transition. (unit: millisecond) > - dev_name : Device name of h/w. > - dev : Device name made by devfreq core. > - parent_dev : If devfreq device uses the passive governor, > show parent devfreq device name. > - load_% : If devfreq device uses the simple_ondemand governor, > load is used by governor whene deciding the new frequency. > (unit: percentage) > - old_freq_hz : Frequency before changing. (unit: hz) > - new_freq_hz : Frequency after changed. (unit: hz) > > [For example on Exynos5422-based Odroid-XU3 board] > $ cat /sys/kernel/debug/devfreq/devfreq_transitions > time_ms dev_name dev parent_dev load_% old_freq_hz new_freq_hz > ---------- ------------------------------ ---------- ---------- ---------- ------------ ------------ > 14600 soc:bus_noc devfreq2 devfreq1 0 100000000 67000000 > 14600 soc:bus_fsys_apb devfreq3 devfreq1 0 200000000 100000000 > 14600 soc:bus_fsys devfreq4 devfreq1 0 200000000 100000000 > 14600 soc:bus_fsys2 devfreq5 devfreq1 0 150000000 75000000 > 14602 soc:bus_mfc devfreq6 devfreq1 0 222000000 96000000 > 14602 soc:bus_gen devfreq7 devfreq1 0 267000000 89000000 > 14602 soc:bus_g2d devfreq9 devfreq1 0 300000000 84000000 > 14602 soc:bus_g2d_acp devfreq10 devfreq1 0 267000000 67000000 > 14602 soc:bus_jpeg devfreq11 devfreq1 0 300000000 75000000 > 14602 soc:bus_jpeg_apb devfreq12 devfreq1 0 167000000 84000000 > 14603 soc:bus_disp1_fimd devfreq13 devfreq1 0 200000000 120000000 > 14603 soc:bus_disp1 devfreq14 devfreq1 0 300000000 120000000 > 14606 soc:bus_gscl_scaler devfreq15 devfreq1 0 300000000 150000000 > 14606 soc:bus_mscl devfreq16 devfreq1 0 333000000 84000000 > 14608 soc:bus_wcore devfreq1 9 333000000 84000000 > 14783 10c20000.memory-controller devfreq0 35 825000000 633000000 > 15873 soc:bus_wcore devfreq1 41 84000000 400000000 > 15873 soc:bus_noc devfreq2 devfreq1 0 67000000 100000000 > [snip] > Wouldn't it make more sense to expose this through the tracing framework - like many other subsystems does? Regards, Bjorn
07.01.2020 12:05, Chanwoo Choi пишет: > Add new devfreq_transitions debugfs file to track the frequency transitions > of all devfreq devices for the simple profiling as following: > - /sys/kernel/debug/devfreq/devfreq_transitions > > And the user can decide the storage size (CONFIG_NR_DEVFREQ_TRANSITIONS) > in Kconfig in order to save the transition history. > > [Detailed description of each field of 'devfreq_transitions' debugfs file] > - time_ms : Change time of frequency transition. (unit: millisecond) > - dev_name : Device name of h/w. > - dev : Device name made by devfreq core. > - parent_dev : If devfreq device uses the passive governor, > show parent devfreq device name. > - load_% : If devfreq device uses the simple_ondemand governor, > load is used by governor whene deciding the new frequency. > (unit: percentage) > - old_freq_hz : Frequency before changing. (unit: hz) > - new_freq_hz : Frequency after changed. (unit: hz) > > [For example on Exynos5422-based Odroid-XU3 board] > $ cat /sys/kernel/debug/devfreq/devfreq_transitions > time_ms dev_name dev parent_dev load_% old_freq_hz new_freq_hz > ---------- ------------------------------ ---------- ---------- ---------- ------------ ------------ > 14600 soc:bus_noc devfreq2 devfreq1 0 100000000 67000000 > 14600 soc:bus_fsys_apb devfreq3 devfreq1 0 200000000 100000000 > 14600 soc:bus_fsys devfreq4 devfreq1 0 200000000 100000000 > 14600 soc:bus_fsys2 devfreq5 devfreq1 0 150000000 75000000 > 14602 soc:bus_mfc devfreq6 devfreq1 0 222000000 96000000 > 14602 soc:bus_gen devfreq7 devfreq1 0 267000000 89000000 > 14602 soc:bus_g2d devfreq9 devfreq1 0 300000000 84000000 > 14602 soc:bus_g2d_acp devfreq10 devfreq1 0 267000000 67000000 > 14602 soc:bus_jpeg devfreq11 devfreq1 0 300000000 75000000 > 14602 soc:bus_jpeg_apb devfreq12 devfreq1 0 167000000 84000000 > 14603 soc:bus_disp1_fimd devfreq13 devfreq1 0 200000000 120000000 > 14603 soc:bus_disp1 devfreq14 devfreq1 0 300000000 120000000 > 14606 soc:bus_gscl_scaler devfreq15 devfreq1 0 300000000 150000000 > 14606 soc:bus_mscl devfreq16 devfreq1 0 333000000 84000000 > 14608 soc:bus_wcore devfreq1 9 333000000 84000000 > 14783 10c20000.memory-controller devfreq0 35 825000000 633000000 > 15873 soc:bus_wcore devfreq1 41 84000000 400000000 > 15873 soc:bus_noc devfreq2 devfreq1 0 67000000 100000000 > [snip] > > Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> > --- > drivers/devfreq/Kconfig | 13 +++ > drivers/devfreq/devfreq.c | 126 +++++++++++++++++++++++++++++ > drivers/devfreq/governor.h | 3 + > drivers/devfreq/governor_passive.c | 2 + > include/linux/devfreq.h | 1 + > 5 files changed, 145 insertions(+) > > diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig > index 0b1df12e0f21..84936eec0ef9 100644 > --- a/drivers/devfreq/Kconfig > +++ b/drivers/devfreq/Kconfig > @@ -74,6 +74,19 @@ config DEVFREQ_GOV_PASSIVE > through sysfs entries. The passive governor recommends that > devfreq device uses the OPP table to get the frequency/voltage. > > +comment "DEVFREQ Debugging" > + > +config NR_DEVFREQ_TRANSITIONS > + int "Maximum storage size to save DEVFREQ Transitions (10-1000)" > + depends on DEBUG_FS > + range 10 1000 > + default "100" > + help > + Show the frequency transitions of all devfreq devices via > + '/sys/kernel/debug/devfreq/devfreq_transitions' for the simple > + profiling. It needs to decide the storage size to save transition > + history of all devfreq devices. > + > comment "DEVFREQ Drivers" > > config ARM_EXYNOS_BUS_DEVFREQ > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c > index c7f5e4e06420..7abaae06fa65 100644 > --- a/drivers/devfreq/devfreq.c > +++ b/drivers/devfreq/devfreq.c > @@ -268,6 +268,57 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq) > } > EXPORT_SYMBOL(devfreq_update_status); > > +/** > + * devfreq_update_transitions() - Update frequency transitions for debugfs file > + * @devfreq: the devfreq instance > + * @old_freq: the previous frequency before changing the frequency > + * @new_freq: the new frequency after frequency is changed > + */ > +struct devfreq_transitions { > + struct devfreq *devfreq; > + struct devfreq_freqs freqs; > + unsigned long load; > +} debugfs_transitions[CONFIG_NR_DEVFREQ_TRANSITIONS]; > + > +static spinlock_t devfreq_debugfs_lock; > +static int debugfs_transitions_index; > + > +void devfreq_update_transitions(struct devfreq *devfreq, > + unsigned long old_freq, unsigned long new_freq, > + unsigned long busy_time, unsigned long total_time) > +{ > + unsigned long load; > + int i; > + > + if (!devfreq_debugfs || !devfreq || (old_freq == new_freq)) > + return; > + > + spin_lock_nested(&devfreq_debugfs_lock, SINGLE_DEPTH_NESTING); > + > + i = debugfs_transitions_index; > + > + /* > + * Calculate the load and if load is larger than 100, > + * initialize to 100 because the unit of load is percentage. > + */ > + load = (total_time == 0 ? 0 : (100 * busy_time) / total_time); > + if (load > 100) > + load = 100; > + > + debugfs_transitions[i].devfreq = devfreq; > + debugfs_transitions[i].freqs.time = ktime_to_ms(ktime_get()); > + debugfs_transitions[i].freqs.old = old_freq; > + debugfs_transitions[i].freqs.new = new_freq; > + debugfs_transitions[i].load = load; > + > + if (++i == CONFIG_NR_DEVFREQ_TRANSITIONS) > + i = 0; > + debugfs_transitions_index = i; > + > + spin_unlock(&devfreq_debugfs_lock); > +} > +EXPORT_SYMBOL(devfreq_update_transitions); > + > /** > * find_devfreq_governor() - Find devfreq governor from name > * @name: name of the governor > @@ -401,6 +452,10 @@ static int set_target(struct devfreq *devfreq, > return err; > } > > + devfreq_update_transitions(devfreq, cur_freq, new_freq, > + devfreq->last_status.busy_time, > + devfreq->last_status.total_time); > + > freqs.new = new_freq; > notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE); > > @@ -1787,6 +1842,72 @@ static int devfreq_summary_show(struct seq_file *s, void *data) > } > DEFINE_SHOW_ATTRIBUTE(devfreq_summary); > > +/** > + * devfreq_transitions_show() - Show the frequency transitions of the registered > + * devfreq devices via 'devfreq_transitions' debugfs file. > + */ > +static int devfreq_transitions_show(struct seq_file *s, void *data) > +{ > + struct devfreq *devfreq = NULL; > + struct devfreq *p_devfreq = NULL; > + struct devfreq_freqs *freqs = NULL; > + unsigned long load; > + int i = debugfs_transitions_index; > + int count; > + > + seq_printf(s, "%-10s %-30s %-10s %-10s %-6s %-12s %-12s\n", > + "time_ms", > + "dev_name", > + "dev", > + "parent_dev", > + "load_%", > + "old_freq_hz", > + "new_freq_hz"); > + seq_printf(s, "%-10s %-30s %-10s %-10s %-6s %-12s %-12s\n", > + "----------", > + "------------------------------", > + "----------", > + "----------", > + "----------", > + "------------", > + "------------"); Isn't this needed here? mutex_lock(&devfreq_list_lock); > + spin_lock(&devfreq_debugfs_lock); > + for (count = 0; count < CONFIG_NR_DEVFREQ_TRANSITIONS; count++) { > + devfreq = debugfs_transitions[i].devfreq; > + freqs = &debugfs_transitions[i].freqs; > + load = debugfs_transitions[i].load; > + > + i = (CONFIG_NR_DEVFREQ_TRANSITIONS == ++i) ? 0 : i; > + if (!devfreq) > + continue; I suppose debugfs_transitions[i].devfreq should be set to NULL when devfreq device is removed, but I don't see it happening anywhere in this patch. > +#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE) > + if (!strncmp(devfreq->governor_name, > + DEVFREQ_GOV_PASSIVE, DEVFREQ_NAME_LEN)) { This could be: if (IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE) && !strncmp(devfreq->governor_name, DEVFREQ_GOV_PASSIVE, DEVFREQ_NAME_LEN)) { > + struct devfreq_passive_data *data = devfreq->data; > + > + if (data) > + p_devfreq = data->parent; const char *devname = ""; ... if (data) devname = dev_name(data->parent); > + } else { > + p_devfreq = NULL; > + } > +#endif > + seq_printf(s, "%-10lld %-30s %-10s %-10s %-6ld %-12ld %-12ld\n", > + freqs->time, > + dev_name(devfreq->dev.parent), > + dev_name(&devfreq->dev), > + p_devfreq ? dev_name(&p_devfreq->dev) : "", > + load, > + freqs->old, > + freqs->new); > + } > + spin_unlock(&devfreq_debugfs_lock); > + > + return 0; > +} > +DEFINE_SHOW_ATTRIBUTE(devfreq_transitions); > + > static int __init devfreq_init(void) > { > devfreq_class = class_create(THIS_MODULE, "devfreq"); > @@ -1808,9 +1929,14 @@ static int __init devfreq_init(void) > devfreq_debugfs = NULL; > pr_warn("%s: couldn't create debugfs dir\n", __FILE__); > } else { > + spin_lock_init(&devfreq_debugfs_lock); > + > debugfs_create_file("devfreq_summary", 0444, > devfreq_debugfs, NULL, > &devfreq_summary_fops); > + debugfs_create_file("devfreq_transitions", 0444, > + devfreq_debugfs, NULL, > + &devfreq_transitions_fops); > } > > return 0; > diff --git a/drivers/devfreq/governor.h b/drivers/devfreq/governor.h > index dc7533ccc3db..01eecfdaf2d6 100644 > --- a/drivers/devfreq/governor.h > +++ b/drivers/devfreq/governor.h > @@ -68,6 +68,9 @@ extern int devfreq_add_governor(struct devfreq_governor *governor); > extern int devfreq_remove_governor(struct devfreq_governor *governor); > > extern int devfreq_update_status(struct devfreq *devfreq, unsigned long freq); > +extern void devfreq_update_transitions(struct devfreq *devfreq, > + unsigned long old_freq, unsigned long new_freq, > + unsigned long busy_time, unsigned long total_time); > > static inline int devfreq_update_stats(struct devfreq *df) > { > diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c > index be6eeab9c814..05fa654239f5 100644 > --- a/drivers/devfreq/governor_passive.c > +++ b/drivers/devfreq/governor_passive.c > @@ -109,6 +109,8 @@ static int update_devfreq_passive(struct devfreq *devfreq, unsigned long freq) > if (ret < 0) > goto out; > > + devfreq_update_transitions(devfreq, devfreq->previous_freq, freq, 0, 0); > + > if (devfreq->profile->freq_table > && (devfreq_update_status(devfreq, freq))) > dev_err(&devfreq->dev, > diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h > index 49cdb2378030..933692e5d867 100644 > --- a/include/linux/devfreq.h > +++ b/include/linux/devfreq.h > @@ -196,6 +196,7 @@ struct devfreq { > }; > > struct devfreq_freqs { > + s64 time; > unsigned long old; > unsigned long new; > }; >
Hi, On 1/8/20 6:31 AM, Dmitry Osipenko wrote: > Hello Chanwoo, > > 07.01.2020 12:05, Chanwoo Choi пишет: >> Add new devfreq_transitions debugfs file to track the frequency transitions >> of all devfreq devices for the simple profiling as following: >> - /sys/kernel/debug/devfreq/devfreq_transitions >> >> And the user can decide the storage size (CONFIG_NR_DEVFREQ_TRANSITIONS) >> in Kconfig in order to save the transition history. >> >> [Detailed description of each field of 'devfreq_transitions' debugfs file] >> - time_ms : Change time of frequency transition. (unit: millisecond) >> - dev_name : Device name of h/w. >> - dev : Device name made by devfreq core. >> - parent_dev : If devfreq device uses the passive governor, >> show parent devfreq device name. >> - load_% : If devfreq device uses the simple_ondemand governor, >> load is used by governor whene deciding the new frequency. >> (unit: percentage) >> - old_freq_hz : Frequency before changing. (unit: hz) >> - new_freq_hz : Frequency after changed. (unit: hz) >> >> [For example on Exynos5422-based Odroid-XU3 board] >> $ cat /sys/kernel/debug/devfreq/devfreq_transitions >> time_ms dev_name dev parent_dev load_% old_freq_hz new_freq_hz >> ---------- ------------------------------ ---------- ---------- ---------- ------------ ------------ >> 14600 soc:bus_noc devfreq2 devfreq1 0 100000000 67000000 >> 14600 soc:bus_fsys_apb devfreq3 devfreq1 0 200000000 100000000 >> 14600 soc:bus_fsys devfreq4 devfreq1 0 200000000 100000000 >> 14600 soc:bus_fsys2 devfreq5 devfreq1 0 150000000 75000000 >> 14602 soc:bus_mfc devfreq6 devfreq1 0 222000000 96000000 >> 14602 soc:bus_gen devfreq7 devfreq1 0 267000000 89000000 >> 14602 soc:bus_g2d devfreq9 devfreq1 0 300000000 84000000 >> 14602 soc:bus_g2d_acp devfreq10 devfreq1 0 267000000 67000000 >> 14602 soc:bus_jpeg devfreq11 devfreq1 0 300000000 75000000 >> 14602 soc:bus_jpeg_apb devfreq12 devfreq1 0 167000000 84000000 >> 14603 soc:bus_disp1_fimd devfreq13 devfreq1 0 200000000 120000000 >> 14603 soc:bus_disp1 devfreq14 devfreq1 0 300000000 120000000 >> 14606 soc:bus_gscl_scaler devfreq15 devfreq1 0 300000000 150000000 >> 14606 soc:bus_mscl devfreq16 devfreq1 0 333000000 84000000 >> 14608 soc:bus_wcore devfreq1 9 333000000 84000000 >> 14783 10c20000.memory-controller devfreq0 35 825000000 633000000 >> 15873 soc:bus_wcore devfreq1 41 84000000 400000000 >> 15873 soc:bus_noc devfreq2 devfreq1 0 67000000 100000000 >> [snip] >> >> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> >> --- >> drivers/devfreq/Kconfig | 13 +++ >> drivers/devfreq/devfreq.c | 126 +++++++++++++++++++++++++++++ >> drivers/devfreq/governor.h | 3 + >> drivers/devfreq/governor_passive.c | 2 + >> include/linux/devfreq.h | 1 + >> 5 files changed, 145 insertions(+) >> >> diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig >> index 0b1df12e0f21..84936eec0ef9 100644 >> --- a/drivers/devfreq/Kconfig >> +++ b/drivers/devfreq/Kconfig >> @@ -74,6 +74,19 @@ config DEVFREQ_GOV_PASSIVE >> through sysfs entries. The passive governor recommends that >> devfreq device uses the OPP table to get the frequency/voltage. >> >> +comment "DEVFREQ Debugging" >> + >> +config NR_DEVFREQ_TRANSITIONS >> + int "Maximum storage size to save DEVFREQ Transitions (10-1000)" >> + depends on DEBUG_FS >> + range 10 1000 >> + default "100" >> + help >> + Show the frequency transitions of all devfreq devices via >> + '/sys/kernel/debug/devfreq/devfreq_transitions' for the simple >> + profiling. It needs to decide the storage size to save transition >> + history of all devfreq devices. >> + >> comment "DEVFREQ Drivers" >> >> config ARM_EXYNOS_BUS_DEVFREQ >> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c >> index c7f5e4e06420..7abaae06fa65 100644 >> --- a/drivers/devfreq/devfreq.c >> +++ b/drivers/devfreq/devfreq.c >> @@ -268,6 +268,57 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq) >> } >> EXPORT_SYMBOL(devfreq_update_status); >> +/** >> + * devfreq_update_transitions() - Update frequency transitions for debugfs file >> + * @devfreq: the devfreq instance >> + * @old_freq: the previous frequency before changing the frequency >> + * @new_freq: the new frequency after frequency is changed >> + */ >> +struct devfreq_transitions { >> + struct devfreq *devfreq; >> + struct devfreq_freqs freqs; >> + unsigned long load; >> +} debugfs_transitions[CONFIG_NR_DEVFREQ_TRANSITIONS]; >> + >> +static spinlock_t devfreq_debugfs_lock; > > This could be: > > static DEFINE_SPINLOCK(devfreq_debugfs_lock); > > and then spin_lock_init() isn't needed. OK > > > Also, The "<linux/spinlock.h>" should be included directly by devfreq.c OK. > >> +static int debugfs_transitions_index; >> + >> +void devfreq_update_transitions(struct devfreq *devfreq, >> + unsigned long old_freq, unsigned long new_freq, >> + unsigned long busy_time, unsigned long total_time) >> +{ >> + unsigned long load; >> + int i; >> + >> + if (!devfreq_debugfs || !devfreq || (old_freq == new_freq)) >> + return; >> + >> + spin_lock_nested(&devfreq_debugfs_lock, SINGLE_DEPTH_NESTING); >> + >> + i = debugfs_transitions_index; >> + >> + /* >> + * Calculate the load and if load is larger than 100, >> + * initialize to 100 because the unit of load is percentage. >> + */ >> + load = (total_time == 0 ? 0 : (100 * busy_time) / total_time); >> + if (load > 100) >> + load = 100; >> + >> + debugfs_transitions[i].devfreq = devfreq; >> + debugfs_transitions[i].freqs.time = ktime_to_ms(ktime_get()); >> + debugfs_transitions[i].freqs.old = old_freq; >> + debugfs_transitions[i].freqs.new = new_freq; >> + debugfs_transitions[i].load = load; >> + >> + if (++i == CONFIG_NR_DEVFREQ_TRANSITIONS) >> + i = 0; >> + debugfs_transitions_index = i; >> + >> + spin_unlock(&devfreq_debugfs_lock); >> +} >> +EXPORT_SYMBOL(devfreq_update_transitions); > > What about EXPORT_SYMBOL_GPL()? I'll remove it. > >> /** >> * find_devfreq_governor() - Find devfreq governor from name >> * @name: name of the governor >> @@ -401,6 +452,10 @@ static int set_target(struct devfreq *devfreq, >> return err; >> } >> >> + devfreq_update_transitions(devfreq, cur_freq, new_freq, >> + devfreq->last_status.busy_time, >> + devfreq->last_status.total_time); >> + >> freqs.new = new_freq; >> notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE); >> >> @@ -1787,6 +1842,72 @@ static int devfreq_summary_show(struct seq_file *s, void *data) >> } >> DEFINE_SHOW_ATTRIBUTE(devfreq_summary); >> >> +/** >> + * devfreq_transitions_show() - Show the frequency transitions of the registered >> + * devfreq devices via 'devfreq_transitions' debugfs file. >> + */ >> +static int devfreq_transitions_show(struct seq_file *s, void *data) >> +{ >> + struct devfreq *devfreq = NULL; >> + struct devfreq *p_devfreq = NULL; >> + struct devfreq_freqs *freqs = NULL; >> + unsigned long load; >> + int i = debugfs_transitions_index; >> + int count; >> + >> + seq_printf(s, "%-10s %-30s %-10s %-10s %-6s %-12s %-12s\n", >> + "time_ms", >> + "dev_name", >> + "dev", >> + "parent_dev", >> + "load_%", >> + "old_freq_hz", >> + "new_freq_hz"); >> + seq_printf(s, "%-10s %-30s %-10s %-10s %-6s %-12s %-12s\n", >> + "----------", >> + "------------------------------", >> + "----------", >> + "----------", >> + "----------", >> + "------------", >> + "------------"); >> + >> + spin_lock(&devfreq_debugfs_lock);> + for (count = 0; count < CONFIG_NR_DEVFREQ_TRANSITIONS; count++) { >> + devfreq = debugfs_transitions[i].devfreq; >> + freqs = &debugfs_transitions[i].freqs; >> + load = debugfs_transitions[i].load; >> + >> + i = (CONFIG_NR_DEVFREQ_TRANSITIONS == ++i) ? 0 : i; >> + if (!devfreq) >> + continue; >> + >> +#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE) >> + if (!strncmp(devfreq->governor_name, >> + DEVFREQ_GOV_PASSIVE, DEVFREQ_NAME_LEN)) { >> + struct devfreq_passive_data *data = devfreq->data; >> + >> + if (data) >> + p_devfreq = data->parent; >> + } else { >> + p_devfreq = NULL; >> + } >> +#endif >> + seq_printf(s, "%-10lld %-30s %-10s %-10s %-6ld %-12ld %-12ld\n", >> + freqs->time, >> + dev_name(devfreq->dev.parent), >> + dev_name(&devfreq->dev), >> + p_devfreq ? dev_name(&p_devfreq->dev) : "", >> + load, >> + freqs->old, >> + freqs->new); >> + } >> + spin_unlock(&devfreq_debugfs_lock); >> + >> + return 0; >> +} >> +DEFINE_SHOW_ATTRIBUTE(devfreq_transitions); >> + >> static int __init devfreq_init(void) >> { >> devfreq_class = class_create(THIS_MODULE, "devfreq"); >> @@ -1808,9 +1929,14 @@ static int __init devfreq_init(void) >> devfreq_debugfs = NULL; >> pr_warn("%s: couldn't create debugfs dir\n", __FILE__); >> } else { >> + spin_lock_init(&devfreq_debugfs_lock); >> + >> debugfs_create_file("devfreq_summary", 0444, >> devfreq_debugfs, NULL, >> &devfreq_summary_fops); >> + debugfs_create_file("devfreq_transitions", 0444, >> + devfreq_debugfs, NULL, >> + &devfreq_transitions_fops); >> } >> >> return 0; >> diff --git a/drivers/devfreq/governor.h b/drivers/devfreq/governor.h >> index dc7533ccc3db..01eecfdaf2d6 100644 >> --- a/drivers/devfreq/governor.h >> +++ b/drivers/devfreq/governor.h >> @@ -68,6 +68,9 @@ extern int devfreq_add_governor(struct devfreq_governor *governor); >> extern int devfreq_remove_governor(struct devfreq_governor *governor); >> >> extern int devfreq_update_status(struct devfreq *devfreq, unsigned long freq); >> +extern void devfreq_update_transitions(struct devfreq *devfreq, >> + unsigned long old_freq, unsigned long new_freq, >> + unsigned long busy_time, unsigned long total_time); > > The 'extern' attribute isn't needed for function prototypes defined in > header files. > > Right. I'll remove it.
On 1/8/20 6:56 AM, Dmitry Osipenko wrote: > 07.01.2020 12:05, Chanwoo Choi пишет: >> Add new devfreq_transitions debugfs file to track the frequency transitions >> of all devfreq devices for the simple profiling as following: >> - /sys/kernel/debug/devfreq/devfreq_transitions >> >> And the user can decide the storage size (CONFIG_NR_DEVFREQ_TRANSITIONS) >> in Kconfig in order to save the transition history. >> >> [Detailed description of each field of 'devfreq_transitions' debugfs file] >> - time_ms : Change time of frequency transition. (unit: millisecond) >> - dev_name : Device name of h/w. >> - dev : Device name made by devfreq core. >> - parent_dev : If devfreq device uses the passive governor, >> show parent devfreq device name. >> - load_% : If devfreq device uses the simple_ondemand governor, >> load is used by governor whene deciding the new frequency. >> (unit: percentage) >> - old_freq_hz : Frequency before changing. (unit: hz) >> - new_freq_hz : Frequency after changed. (unit: hz) >> >> [For example on Exynos5422-based Odroid-XU3 board] >> $ cat /sys/kernel/debug/devfreq/devfreq_transitions >> time_ms dev_name dev parent_dev load_% old_freq_hz new_freq_hz >> ---------- ------------------------------ ---------- ---------- ---------- ------------ ------------ >> 14600 soc:bus_noc devfreq2 devfreq1 0 100000000 67000000 >> 14600 soc:bus_fsys_apb devfreq3 devfreq1 0 200000000 100000000 >> 14600 soc:bus_fsys devfreq4 devfreq1 0 200000000 100000000 >> 14600 soc:bus_fsys2 devfreq5 devfreq1 0 150000000 75000000 >> 14602 soc:bus_mfc devfreq6 devfreq1 0 222000000 96000000 >> 14602 soc:bus_gen devfreq7 devfreq1 0 267000000 89000000 >> 14602 soc:bus_g2d devfreq9 devfreq1 0 300000000 84000000 >> 14602 soc:bus_g2d_acp devfreq10 devfreq1 0 267000000 67000000 >> 14602 soc:bus_jpeg devfreq11 devfreq1 0 300000000 75000000 >> 14602 soc:bus_jpeg_apb devfreq12 devfreq1 0 167000000 84000000 >> 14603 soc:bus_disp1_fimd devfreq13 devfreq1 0 200000000 120000000 >> 14603 soc:bus_disp1 devfreq14 devfreq1 0 300000000 120000000 >> 14606 soc:bus_gscl_scaler devfreq15 devfreq1 0 300000000 150000000 >> 14606 soc:bus_mscl devfreq16 devfreq1 0 333000000 84000000 >> 14608 soc:bus_wcore devfreq1 9 333000000 84000000 >> 14783 10c20000.memory-controller devfreq0 35 825000000 633000000 >> 15873 soc:bus_wcore devfreq1 41 84000000 400000000 >> 15873 soc:bus_noc devfreq2 devfreq1 0 67000000 100000000 >> [snip] >> >> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> >> --- >> drivers/devfreq/Kconfig | 13 +++ >> drivers/devfreq/devfreq.c | 126 +++++++++++++++++++++++++++++ >> drivers/devfreq/governor.h | 3 + >> drivers/devfreq/governor_passive.c | 2 + >> include/linux/devfreq.h | 1 + >> 5 files changed, 145 insertions(+) >> >> diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig >> index 0b1df12e0f21..84936eec0ef9 100644 >> --- a/drivers/devfreq/Kconfig >> +++ b/drivers/devfreq/Kconfig >> @@ -74,6 +74,19 @@ config DEVFREQ_GOV_PASSIVE >> through sysfs entries. The passive governor recommends that >> devfreq device uses the OPP table to get the frequency/voltage. >> >> +comment "DEVFREQ Debugging" >> + >> +config NR_DEVFREQ_TRANSITIONS >> + int "Maximum storage size to save DEVFREQ Transitions (10-1000)" >> + depends on DEBUG_FS >> + range 10 1000 >> + default "100" >> + help >> + Show the frequency transitions of all devfreq devices via >> + '/sys/kernel/debug/devfreq/devfreq_transitions' for the simple >> + profiling. It needs to decide the storage size to save transition >> + history of all devfreq devices. >> + >> comment "DEVFREQ Drivers" >> >> config ARM_EXYNOS_BUS_DEVFREQ >> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c >> index c7f5e4e06420..7abaae06fa65 100644 >> --- a/drivers/devfreq/devfreq.c >> +++ b/drivers/devfreq/devfreq.c >> @@ -268,6 +268,57 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq) >> } >> EXPORT_SYMBOL(devfreq_update_status); >> >> +/** >> + * devfreq_update_transitions() - Update frequency transitions for debugfs file >> + * @devfreq: the devfreq instance >> + * @old_freq: the previous frequency before changing the frequency >> + * @new_freq: the new frequency after frequency is changed >> + */ >> +struct devfreq_transitions { >> + struct devfreq *devfreq; >> + struct devfreq_freqs freqs; >> + unsigned long load; >> +} debugfs_transitions[CONFIG_NR_DEVFREQ_TRANSITIONS]; >> + >> +static spinlock_t devfreq_debugfs_lock; >> +static int debugfs_transitions_index; >> + >> +void devfreq_update_transitions(struct devfreq *devfreq, >> + unsigned long old_freq, unsigned long new_freq, >> + unsigned long busy_time, unsigned long total_time) >> +{ >> + unsigned long load; >> + int i; >> + >> + if (!devfreq_debugfs || !devfreq || (old_freq == new_freq)) >> + return; >> + >> + spin_lock_nested(&devfreq_debugfs_lock, SINGLE_DEPTH_NESTING); >> + >> + i = debugfs_transitions_index; >> + >> + /* >> + * Calculate the load and if load is larger than 100, >> + * initialize to 100 because the unit of load is percentage. >> + */ >> + load = (total_time == 0 ? 0 : (100 * busy_time) / total_time); >> + if (load > 100) >> + load = 100; >> + >> + debugfs_transitions[i].devfreq = devfreq; >> + debugfs_transitions[i].freqs.time = ktime_to_ms(ktime_get()); >> + debugfs_transitions[i].freqs.old = old_freq; >> + debugfs_transitions[i].freqs.new = new_freq; >> + debugfs_transitions[i].load = load; >> + >> + if (++i == CONFIG_NR_DEVFREQ_TRANSITIONS) >> + i = 0; >> + debugfs_transitions_index = i; >> + >> + spin_unlock(&devfreq_debugfs_lock); >> +} >> +EXPORT_SYMBOL(devfreq_update_transitions); >> + >> /** >> * find_devfreq_governor() - Find devfreq governor from name >> * @name: name of the governor >> @@ -401,6 +452,10 @@ static int set_target(struct devfreq *devfreq, >> return err; >> } >> >> + devfreq_update_transitions(devfreq, cur_freq, new_freq, >> + devfreq->last_status.busy_time, >> + devfreq->last_status.total_time); >> + >> freqs.new = new_freq; >> notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE); >> >> @@ -1787,6 +1842,72 @@ static int devfreq_summary_show(struct seq_file *s, void *data) >> } >> DEFINE_SHOW_ATTRIBUTE(devfreq_summary); >> >> +/** >> + * devfreq_transitions_show() - Show the frequency transitions of the registered >> + * devfreq devices via 'devfreq_transitions' debugfs file. >> + */ >> +static int devfreq_transitions_show(struct seq_file *s, void *data) >> +{ >> + struct devfreq *devfreq = NULL; >> + struct devfreq *p_devfreq = NULL; >> + struct devfreq_freqs *freqs = NULL; >> + unsigned long load; >> + int i = debugfs_transitions_index; >> + int count; >> + >> + seq_printf(s, "%-10s %-30s %-10s %-10s %-6s %-12s %-12s\n", >> + "time_ms", >> + "dev_name", >> + "dev", >> + "parent_dev", >> + "load_%", >> + "old_freq_hz", >> + "new_freq_hz"); >> + seq_printf(s, "%-10s %-30s %-10s %-10s %-6s %-12s %-12s\n", >> + "----------", >> + "------------------------------", >> + "----------", >> + "----------", >> + "----------", >> + "------------", >> + "------------"); > > Isn't this needed here? > > mutex_lock(&devfreq_list_lock); It doesn't touch the devfreq instance of devfreq_list. So, it is not necessary locked of devfreq_list_lock. > >> + spin_lock(&devfreq_debugfs_lock); >> + for (count = 0; count < CONFIG_NR_DEVFREQ_TRANSITIONS; count++) { >> + devfreq = debugfs_transitions[i].devfreq; >> + freqs = &debugfs_transitions[i].freqs; >> + load = debugfs_transitions[i].load; >> + >> + i = (CONFIG_NR_DEVFREQ_TRANSITIONS == ++i) ? 0 : i; >> + if (!devfreq) >> + continue; > > I suppose debugfs_transitions[i].devfreq should be set to NULL when > devfreq device is removed, but I don't see it happening anywhere in this > patch. When debugfs_transitions[] array is not fully filled out by devfreq_update_transitions(), debugfs_transitions[i].devfreq is NULL. In this case, if user execute 'cat /sys/kernel/debug/devfreq/devfreq_transitions', devfreq_transitions_show() need to check the debugfs_transitions[i].devfreq is NULL or not. After filled out the debugfs_transitions[] array, actually, 'if(!devfreq)' is not necessary. Maybe, this style is inefficient It need to rework. I'll think again. > >> +#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE) >> + if (!strncmp(devfreq->governor_name, >> + DEVFREQ_GOV_PASSIVE, DEVFREQ_NAME_LEN)) { > > This could be: > > if (IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE) && > !strncmp(devfreq->governor_name, > DEVFREQ_GOV_PASSIVE, DEVFREQ_NAME_LEN)) { Good. It is more clear. I'll edit it according to your comment. > >> + struct devfreq_passive_data *data = devfreq->data; >> + >> + if (data) >> + p_devfreq = data->parent; > > const char *devname = ""; > > ... > > if (data) > devname = dev_name(data->parent); > 'devname' word is too general. It is difficult to know this name is for parent devfreq device. So, I prefer to keep the origin style. >> + } else { >> + p_devfreq = NULL; >> + } >> +#endif >> + seq_printf(s, "%-10lld %-30s %-10s %-10s %-6ld %-12ld %-12ld\n", >> + freqs->time, >> + dev_name(devfreq->dev.parent), >> + dev_name(&devfreq->dev), >> + p_devfreq ? dev_name(&p_devfreq->dev) : "", >> + load, >> + freqs->old, >> + freqs->new); >> + } >> + spin_unlock(&devfreq_debugfs_lock); >> + >> + return 0; >> +} >> +DEFINE_SHOW_ATTRIBUTE(devfreq_transitions); >> + >> static int __init devfreq_init(void) >> { >> devfreq_class = class_create(THIS_MODULE, "devfreq"); >> @@ -1808,9 +1929,14 @@ static int __init devfreq_init(void) >> devfreq_debugfs = NULL; >> pr_warn("%s: couldn't create debugfs dir\n", __FILE__); >> } else { >> + spin_lock_init(&devfreq_debugfs_lock); >> + >> debugfs_create_file("devfreq_summary", 0444, >> devfreq_debugfs, NULL, >> &devfreq_summary_fops); >> + debugfs_create_file("devfreq_transitions", 0444, >> + devfreq_debugfs, NULL, >> + &devfreq_transitions_fops); >> } >> >> return 0; >> diff --git a/drivers/devfreq/governor.h b/drivers/devfreq/governor.h >> index dc7533ccc3db..01eecfdaf2d6 100644 >> --- a/drivers/devfreq/governor.h >> +++ b/drivers/devfreq/governor.h >> @@ -68,6 +68,9 @@ extern int devfreq_add_governor(struct devfreq_governor *governor); >> extern int devfreq_remove_governor(struct devfreq_governor *governor); >> >> extern int devfreq_update_status(struct devfreq *devfreq, unsigned long freq); >> +extern void devfreq_update_transitions(struct devfreq *devfreq, >> + unsigned long old_freq, unsigned long new_freq, >> + unsigned long busy_time, unsigned long total_time); >> >> static inline int devfreq_update_stats(struct devfreq *df) >> { >> diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c >> index be6eeab9c814..05fa654239f5 100644 >> --- a/drivers/devfreq/governor_passive.c >> +++ b/drivers/devfreq/governor_passive.c >> @@ -109,6 +109,8 @@ static int update_devfreq_passive(struct devfreq *devfreq, unsigned long freq) >> if (ret < 0) >> goto out; >> >> + devfreq_update_transitions(devfreq, devfreq->previous_freq, freq, 0, 0); >> + >> if (devfreq->profile->freq_table >> && (devfreq_update_status(devfreq, freq))) >> dev_err(&devfreq->dev, >> diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h >> index 49cdb2378030..933692e5d867 100644 >> --- a/include/linux/devfreq.h >> +++ b/include/linux/devfreq.h >> @@ -196,6 +196,7 @@ struct devfreq { >> }; >> >> struct devfreq_freqs { >> + s64 time; >> unsigned long old; >> unsigned long new; >> }; >> > > >
On 1/8/20 8:22 PM, Chanwoo Choi wrote: > On 1/8/20 6:56 AM, Dmitry Osipenko wrote: >> 07.01.2020 12:05, Chanwoo Choi пишет: >>> Add new devfreq_transitions debugfs file to track the frequency transitions >>> of all devfreq devices for the simple profiling as following: >>> - /sys/kernel/debug/devfreq/devfreq_transitions >>> >>> And the user can decide the storage size (CONFIG_NR_DEVFREQ_TRANSITIONS) >>> in Kconfig in order to save the transition history. >>> >>> [Detailed description of each field of 'devfreq_transitions' debugfs file] >>> - time_ms : Change time of frequency transition. (unit: millisecond) >>> - dev_name : Device name of h/w. >>> - dev : Device name made by devfreq core. >>> - parent_dev : If devfreq device uses the passive governor, >>> show parent devfreq device name. >>> - load_% : If devfreq device uses the simple_ondemand governor, >>> load is used by governor whene deciding the new frequency. >>> (unit: percentage) >>> - old_freq_hz : Frequency before changing. (unit: hz) >>> - new_freq_hz : Frequency after changed. (unit: hz) >>> >>> [For example on Exynos5422-based Odroid-XU3 board] >>> $ cat /sys/kernel/debug/devfreq/devfreq_transitions >>> time_ms dev_name dev parent_dev load_% old_freq_hz new_freq_hz >>> ---------- ------------------------------ ---------- ---------- ---------- ------------ ------------ >>> 14600 soc:bus_noc devfreq2 devfreq1 0 100000000 67000000 >>> 14600 soc:bus_fsys_apb devfreq3 devfreq1 0 200000000 100000000 >>> 14600 soc:bus_fsys devfreq4 devfreq1 0 200000000 100000000 >>> 14600 soc:bus_fsys2 devfreq5 devfreq1 0 150000000 75000000 >>> 14602 soc:bus_mfc devfreq6 devfreq1 0 222000000 96000000 >>> 14602 soc:bus_gen devfreq7 devfreq1 0 267000000 89000000 >>> 14602 soc:bus_g2d devfreq9 devfreq1 0 300000000 84000000 >>> 14602 soc:bus_g2d_acp devfreq10 devfreq1 0 267000000 67000000 >>> 14602 soc:bus_jpeg devfreq11 devfreq1 0 300000000 75000000 >>> 14602 soc:bus_jpeg_apb devfreq12 devfreq1 0 167000000 84000000 >>> 14603 soc:bus_disp1_fimd devfreq13 devfreq1 0 200000000 120000000 >>> 14603 soc:bus_disp1 devfreq14 devfreq1 0 300000000 120000000 >>> 14606 soc:bus_gscl_scaler devfreq15 devfreq1 0 300000000 150000000 >>> 14606 soc:bus_mscl devfreq16 devfreq1 0 333000000 84000000 >>> 14608 soc:bus_wcore devfreq1 9 333000000 84000000 >>> 14783 10c20000.memory-controller devfreq0 35 825000000 633000000 >>> 15873 soc:bus_wcore devfreq1 41 84000000 400000000 >>> 15873 soc:bus_noc devfreq2 devfreq1 0 67000000 100000000 >>> [snip] >>> >>> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> >>> --- >>> drivers/devfreq/Kconfig | 13 +++ >>> drivers/devfreq/devfreq.c | 126 +++++++++++++++++++++++++++++ >>> drivers/devfreq/governor.h | 3 + >>> drivers/devfreq/governor_passive.c | 2 + >>> include/linux/devfreq.h | 1 + >>> 5 files changed, 145 insertions(+) >>> >>> diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig >>> index 0b1df12e0f21..84936eec0ef9 100644 >>> --- a/drivers/devfreq/Kconfig >>> +++ b/drivers/devfreq/Kconfig >>> @@ -74,6 +74,19 @@ config DEVFREQ_GOV_PASSIVE >>> through sysfs entries. The passive governor recommends that >>> devfreq device uses the OPP table to get the frequency/voltage. >>> >>> +comment "DEVFREQ Debugging" >>> + >>> +config NR_DEVFREQ_TRANSITIONS >>> + int "Maximum storage size to save DEVFREQ Transitions (10-1000)" >>> + depends on DEBUG_FS >>> + range 10 1000 >>> + default "100" >>> + help >>> + Show the frequency transitions of all devfreq devices via >>> + '/sys/kernel/debug/devfreq/devfreq_transitions' for the simple >>> + profiling. It needs to decide the storage size to save transition >>> + history of all devfreq devices. >>> + >>> comment "DEVFREQ Drivers" >>> >>> config ARM_EXYNOS_BUS_DEVFREQ >>> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c >>> index c7f5e4e06420..7abaae06fa65 100644 >>> --- a/drivers/devfreq/devfreq.c >>> +++ b/drivers/devfreq/devfreq.c >>> @@ -268,6 +268,57 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq) >>> } >>> EXPORT_SYMBOL(devfreq_update_status); >>> >>> +/** >>> + * devfreq_update_transitions() - Update frequency transitions for debugfs file >>> + * @devfreq: the devfreq instance >>> + * @old_freq: the previous frequency before changing the frequency >>> + * @new_freq: the new frequency after frequency is changed >>> + */ >>> +struct devfreq_transitions { >>> + struct devfreq *devfreq; >>> + struct devfreq_freqs freqs; >>> + unsigned long load; >>> +} debugfs_transitions[CONFIG_NR_DEVFREQ_TRANSITIONS]; >>> + >>> +static spinlock_t devfreq_debugfs_lock; >>> +static int debugfs_transitions_index; >>> + >>> +void devfreq_update_transitions(struct devfreq *devfreq, >>> + unsigned long old_freq, unsigned long new_freq, >>> + unsigned long busy_time, unsigned long total_time) >>> +{ >>> + unsigned long load; >>> + int i; >>> + >>> + if (!devfreq_debugfs || !devfreq || (old_freq == new_freq)) >>> + return; >>> + >>> + spin_lock_nested(&devfreq_debugfs_lock, SINGLE_DEPTH_NESTING); >>> + >>> + i = debugfs_transitions_index; >>> + >>> + /* >>> + * Calculate the load and if load is larger than 100, >>> + * initialize to 100 because the unit of load is percentage. >>> + */ >>> + load = (total_time == 0 ? 0 : (100 * busy_time) / total_time); >>> + if (load > 100) >>> + load = 100; >>> + >>> + debugfs_transitions[i].devfreq = devfreq; >>> + debugfs_transitions[i].freqs.time = ktime_to_ms(ktime_get()); >>> + debugfs_transitions[i].freqs.old = old_freq; >>> + debugfs_transitions[i].freqs.new = new_freq; >>> + debugfs_transitions[i].load = load; >>> + >>> + if (++i == CONFIG_NR_DEVFREQ_TRANSITIONS) >>> + i = 0; >>> + debugfs_transitions_index = i; >>> + >>> + spin_unlock(&devfreq_debugfs_lock); >>> +} >>> +EXPORT_SYMBOL(devfreq_update_transitions); >>> + >>> /** >>> * find_devfreq_governor() - Find devfreq governor from name >>> * @name: name of the governor >>> @@ -401,6 +452,10 @@ static int set_target(struct devfreq *devfreq, >>> return err; >>> } >>> >>> + devfreq_update_transitions(devfreq, cur_freq, new_freq, >>> + devfreq->last_status.busy_time, >>> + devfreq->last_status.total_time); >>> + >>> freqs.new = new_freq; >>> notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE); >>> >>> @@ -1787,6 +1842,72 @@ static int devfreq_summary_show(struct seq_file *s, void *data) >>> } >>> DEFINE_SHOW_ATTRIBUTE(devfreq_summary); >>> >>> +/** >>> + * devfreq_transitions_show() - Show the frequency transitions of the registered >>> + * devfreq devices via 'devfreq_transitions' debugfs file. >>> + */ >>> +static int devfreq_transitions_show(struct seq_file *s, void *data) >>> +{ >>> + struct devfreq *devfreq = NULL; >>> + struct devfreq *p_devfreq = NULL; >>> + struct devfreq_freqs *freqs = NULL; >>> + unsigned long load; >>> + int i = debugfs_transitions_index; >>> + int count; >>> + >>> + seq_printf(s, "%-10s %-30s %-10s %-10s %-6s %-12s %-12s\n", >>> + "time_ms", >>> + "dev_name", >>> + "dev", >>> + "parent_dev", >>> + "load_%", >>> + "old_freq_hz", >>> + "new_freq_hz"); >>> + seq_printf(s, "%-10s %-30s %-10s %-10s %-6s %-12s %-12s\n", >>> + "----------", >>> + "------------------------------", >>> + "----------", >>> + "----------", >>> + "----------", >>> + "------------", >>> + "------------"); >> >> Isn't this needed here? >> >> mutex_lock(&devfreq_list_lock); > > It doesn't touch the devfreq instance of devfreq_list. > So, it is not necessary locked of devfreq_list_lock. > >> >>> + spin_lock(&devfreq_debugfs_lock); >>> + for (count = 0; count < CONFIG_NR_DEVFREQ_TRANSITIONS; count++) { >>> + devfreq = debugfs_transitions[i].devfreq; >>> + freqs = &debugfs_transitions[i].freqs; >>> + load = debugfs_transitions[i].load; >>> + >>> + i = (CONFIG_NR_DEVFREQ_TRANSITIONS == ++i) ? 0 : i; >>> + if (!devfreq) >>> + continue; >> >> I suppose debugfs_transitions[i].devfreq should be set to NULL when >> devfreq device is removed, but I don't see it happening anywhere in this >> patch. > > When debugfs_transitions[] array is not fully filled out > by devfreq_update_transitions(), debugfs_transitions[i].devfreq is NULL. > In this case, if user execute 'cat /sys/kernel/debug/devfreq/devfreq_transitions', > devfreq_transitions_show() need to check the debugfs_transitions[i].devfreq > is NULL or not. > > After filled out the debugfs_transitions[] array, > actually, 'if(!devfreq)' is not necessary. Maybe, this style is inefficient > It need to rework. I'll think again. > >> >>> +#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE) >>> + if (!strncmp(devfreq->governor_name, >>> + DEVFREQ_GOV_PASSIVE, DEVFREQ_NAME_LEN)) { >> >> This could be: >> >> if (IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE) && >> !strncmp(devfreq->governor_name, >> DEVFREQ_GOV_PASSIVE, DEVFREQ_NAME_LEN)) { > > Good. It is more clear. I'll edit it according to your comment. It is my mistake. 'struct devfreq_passive_data' is defined when CONFIG_DEVFREQ_GOV_PASSIVE is enabled. Firstly, I should make 'struct devfreq_passive_data' possible used always regardless of CONFIG_DEVFREQ_GOV_PASSIVE is enabled or not as following: diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h index 36235327bf50..4e9241d0b569 100644 --- a/include/linux/devfreq.h +++ b/include/linux/devfreq.h @@ -277,7 +277,6 @@ struct devfreq_simple_ondemand_data { }; #endif -#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE) /** * struct devfreq_passive_data - void *data fed to struct devfreq * and devfreq_add_device @@ -308,7 +307,6 @@ struct devfreq_passive_data { struct devfreq *this; struct notifier_block nb; }; -#endif > >> >>> + struct devfreq_passive_data *data = devfreq->data; >>> + >>> + if (data) >>> + p_devfreq = data->parent; >> >> const char *devname = ""; >> >> ... >> >> if (data) >> devname = dev_name(data->parent); >> > > 'devname' word is too general. It is difficult to know > this name is for parent devfreq device. So, I prefer > to keep the origin style. > >>> + } else { >>> + p_devfreq = NULL; >>> + } >>> +#endif >>> + seq_printf(s, "%-10lld %-30s %-10s %-10s %-6ld %-12ld %-12ld\n", >>> + freqs->time, >>> + dev_name(devfreq->dev.parent), >>> + dev_name(&devfreq->dev), >>> + p_devfreq ? dev_name(&p_devfreq->dev) : "", >>> + load, >>> + freqs->old, >>> + freqs->new); >>> + } >>> + spin_unlock(&devfreq_debugfs_lock); >>> + >>> + return 0; >>> +} >>> +DEFINE_SHOW_ATTRIBUTE(devfreq_transitions); >>> + >>> static int __init devfreq_init(void) >>> { >>> devfreq_class = class_create(THIS_MODULE, "devfreq"); >>> @@ -1808,9 +1929,14 @@ static int __init devfreq_init(void) >>> devfreq_debugfs = NULL; >>> pr_warn("%s: couldn't create debugfs dir\n", __FILE__); >>> } else { >>> + spin_lock_init(&devfreq_debugfs_lock); >>> + >>> debugfs_create_file("devfreq_summary", 0444, >>> devfreq_debugfs, NULL, >>> &devfreq_summary_fops); >>> + debugfs_create_file("devfreq_transitions", 0444, >>> + devfreq_debugfs, NULL, >>> + &devfreq_transitions_fops); >>> } >>> >>> return 0; >>> diff --git a/drivers/devfreq/governor.h b/drivers/devfreq/governor.h >>> index dc7533ccc3db..01eecfdaf2d6 100644 >>> --- a/drivers/devfreq/governor.h >>> +++ b/drivers/devfreq/governor.h >>> @@ -68,6 +68,9 @@ extern int devfreq_add_governor(struct devfreq_governor *governor); >>> extern int devfreq_remove_governor(struct devfreq_governor *governor); >>> >>> extern int devfreq_update_status(struct devfreq *devfreq, unsigned long freq); >>> +extern void devfreq_update_transitions(struct devfreq *devfreq, >>> + unsigned long old_freq, unsigned long new_freq, >>> + unsigned long busy_time, unsigned long total_time); >>> >>> static inline int devfreq_update_stats(struct devfreq *df) >>> { >>> diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c >>> index be6eeab9c814..05fa654239f5 100644 >>> --- a/drivers/devfreq/governor_passive.c >>> +++ b/drivers/devfreq/governor_passive.c >>> @@ -109,6 +109,8 @@ static int update_devfreq_passive(struct devfreq *devfreq, unsigned long freq) >>> if (ret < 0) >>> goto out; >>> >>> + devfreq_update_transitions(devfreq, devfreq->previous_freq, freq, 0, 0); >>> + >>> if (devfreq->profile->freq_table >>> && (devfreq_update_status(devfreq, freq))) >>> dev_err(&devfreq->dev, >>> diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h >>> index 49cdb2378030..933692e5d867 100644 >>> --- a/include/linux/devfreq.h >>> +++ b/include/linux/devfreq.h >>> @@ -196,6 +196,7 @@ struct devfreq { >>> }; >>> >>> struct devfreq_freqs { >>> + s64 time; >>> unsigned long old; >>> unsigned long new; >>> }; >>> >> >> >> > >
On 1/8/20 7:56 PM, Chanwoo Choi wrote: > Hi, > > On 1/8/20 6:31 AM, Dmitry Osipenko wrote: >> Hello Chanwoo, >> >> 07.01.2020 12:05, Chanwoo Choi пишет: >>> Add new devfreq_transitions debugfs file to track the frequency transitions >>> of all devfreq devices for the simple profiling as following: >>> - /sys/kernel/debug/devfreq/devfreq_transitions >>> >>> And the user can decide the storage size (CONFIG_NR_DEVFREQ_TRANSITIONS) >>> in Kconfig in order to save the transition history. >>> >>> [Detailed description of each field of 'devfreq_transitions' debugfs file] >>> - time_ms : Change time of frequency transition. (unit: millisecond) >>> - dev_name : Device name of h/w. >>> - dev : Device name made by devfreq core. >>> - parent_dev : If devfreq device uses the passive governor, >>> show parent devfreq device name. >>> - load_% : If devfreq device uses the simple_ondemand governor, >>> load is used by governor whene deciding the new frequency. >>> (unit: percentage) >>> - old_freq_hz : Frequency before changing. (unit: hz) >>> - new_freq_hz : Frequency after changed. (unit: hz) >>> >>> [For example on Exynos5422-based Odroid-XU3 board] >>> $ cat /sys/kernel/debug/devfreq/devfreq_transitions >>> time_ms dev_name dev parent_dev load_% old_freq_hz new_freq_hz >>> ---------- ------------------------------ ---------- ---------- ---------- ------------ ------------ >>> 14600 soc:bus_noc devfreq2 devfreq1 0 100000000 67000000 >>> 14600 soc:bus_fsys_apb devfreq3 devfreq1 0 200000000 100000000 >>> 14600 soc:bus_fsys devfreq4 devfreq1 0 200000000 100000000 >>> 14600 soc:bus_fsys2 devfreq5 devfreq1 0 150000000 75000000 >>> 14602 soc:bus_mfc devfreq6 devfreq1 0 222000000 96000000 >>> 14602 soc:bus_gen devfreq7 devfreq1 0 267000000 89000000 >>> 14602 soc:bus_g2d devfreq9 devfreq1 0 300000000 84000000 >>> 14602 soc:bus_g2d_acp devfreq10 devfreq1 0 267000000 67000000 >>> 14602 soc:bus_jpeg devfreq11 devfreq1 0 300000000 75000000 >>> 14602 soc:bus_jpeg_apb devfreq12 devfreq1 0 167000000 84000000 >>> 14603 soc:bus_disp1_fimd devfreq13 devfreq1 0 200000000 120000000 >>> 14603 soc:bus_disp1 devfreq14 devfreq1 0 300000000 120000000 >>> 14606 soc:bus_gscl_scaler devfreq15 devfreq1 0 300000000 150000000 >>> 14606 soc:bus_mscl devfreq16 devfreq1 0 333000000 84000000 >>> 14608 soc:bus_wcore devfreq1 9 333000000 84000000 >>> 14783 10c20000.memory-controller devfreq0 35 825000000 633000000 >>> 15873 soc:bus_wcore devfreq1 41 84000000 400000000 >>> 15873 soc:bus_noc devfreq2 devfreq1 0 67000000 100000000 >>> [snip] >>> >>> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> >>> --- >>> drivers/devfreq/Kconfig | 13 +++ >>> drivers/devfreq/devfreq.c | 126 +++++++++++++++++++++++++++++ >>> drivers/devfreq/governor.h | 3 + >>> drivers/devfreq/governor_passive.c | 2 + >>> include/linux/devfreq.h | 1 + >>> 5 files changed, 145 insertions(+) >>> >>> diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig >>> index 0b1df12e0f21..84936eec0ef9 100644 >>> --- a/drivers/devfreq/Kconfig >>> +++ b/drivers/devfreq/Kconfig >>> @@ -74,6 +74,19 @@ config DEVFREQ_GOV_PASSIVE >>> through sysfs entries. The passive governor recommends that >>> devfreq device uses the OPP table to get the frequency/voltage. >>> >>> +comment "DEVFREQ Debugging" >>> + >>> +config NR_DEVFREQ_TRANSITIONS >>> + int "Maximum storage size to save DEVFREQ Transitions (10-1000)" >>> + depends on DEBUG_FS >>> + range 10 1000 >>> + default "100" >>> + help >>> + Show the frequency transitions of all devfreq devices via >>> + '/sys/kernel/debug/devfreq/devfreq_transitions' for the simple >>> + profiling. It needs to decide the storage size to save transition >>> + history of all devfreq devices. >>> + >>> comment "DEVFREQ Drivers" >>> >>> config ARM_EXYNOS_BUS_DEVFREQ >>> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c >>> index c7f5e4e06420..7abaae06fa65 100644 >>> --- a/drivers/devfreq/devfreq.c >>> +++ b/drivers/devfreq/devfreq.c >>> @@ -268,6 +268,57 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq) >>> } >>> EXPORT_SYMBOL(devfreq_update_status); >>> +/** >>> + * devfreq_update_transitions() - Update frequency transitions for debugfs file >>> + * @devfreq: the devfreq instance >>> + * @old_freq: the previous frequency before changing the frequency >>> + * @new_freq: the new frequency after frequency is changed >>> + */ >>> +struct devfreq_transitions { >>> + struct devfreq *devfreq; >>> + struct devfreq_freqs freqs; >>> + unsigned long load; >>> +} debugfs_transitions[CONFIG_NR_DEVFREQ_TRANSITIONS]; >>> + >>> +static spinlock_t devfreq_debugfs_lock; >> >> This could be: >> >> static DEFINE_SPINLOCK(devfreq_debugfs_lock); >> >> and then spin_lock_init() isn't needed. > > OK > >> >> >> Also, The "<linux/spinlock.h>" should be included directly by devfreq.c > > OK. > >> >>> +static int debugfs_transitions_index; >>> + >>> +void devfreq_update_transitions(struct devfreq *devfreq, >>> + unsigned long old_freq, unsigned long new_freq, >>> + unsigned long busy_time, unsigned long total_time) >>> +{ >>> + unsigned long load; >>> + int i; >>> + >>> + if (!devfreq_debugfs || !devfreq || (old_freq == new_freq)) >>> + return; >>> + >>> + spin_lock_nested(&devfreq_debugfs_lock, SINGLE_DEPTH_NESTING); >>> + >>> + i = debugfs_transitions_index; >>> + >>> + /* >>> + * Calculate the load and if load is larger than 100, >>> + * initialize to 100 because the unit of load is percentage. >>> + */ >>> + load = (total_time == 0 ? 0 : (100 * busy_time) / total_time); >>> + if (load > 100) >>> + load = 100; >>> + >>> + debugfs_transitions[i].devfreq = devfreq; >>> + debugfs_transitions[i].freqs.time = ktime_to_ms(ktime_get()); >>> + debugfs_transitions[i].freqs.old = old_freq; >>> + debugfs_transitions[i].freqs.new = new_freq; >>> + debugfs_transitions[i].load = load; >>> + >>> + if (++i == CONFIG_NR_DEVFREQ_TRANSITIONS) >>> + i = 0; >>> + debugfs_transitions_index = i; >>> + >>> + spin_unlock(&devfreq_debugfs_lock); >>> +} >>> +EXPORT_SYMBOL(devfreq_update_transitions); >> >> What about EXPORT_SYMBOL_GPL()? > > I'll remove it. Ah. It is needed to support module build. it is used by passive governor. > >> >>> /** >>> * find_devfreq_governor() - Find devfreq governor from name >>> * @name: name of the governor >>> @@ -401,6 +452,10 @@ static int set_target(struct devfreq *devfreq, >>> return err; >>> } >>> >>> + devfreq_update_transitions(devfreq, cur_freq, new_freq, >>> + devfreq->last_status.busy_time, >>> + devfreq->last_status.total_time); >>> + >>> freqs.new = new_freq; >>> notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE); >>> >>> @@ -1787,6 +1842,72 @@ static int devfreq_summary_show(struct seq_file *s, void *data) >>> } >>> DEFINE_SHOW_ATTRIBUTE(devfreq_summary); >>> >>> +/** >>> + * devfreq_transitions_show() - Show the frequency transitions of the registered >>> + * devfreq devices via 'devfreq_transitions' debugfs file. >>> + */ >>> +static int devfreq_transitions_show(struct seq_file *s, void *data) >>> +{ >>> + struct devfreq *devfreq = NULL; >>> + struct devfreq *p_devfreq = NULL; >>> + struct devfreq_freqs *freqs = NULL; >>> + unsigned long load; >>> + int i = debugfs_transitions_index; >>> + int count; >>> + >>> + seq_printf(s, "%-10s %-30s %-10s %-10s %-6s %-12s %-12s\n", >>> + "time_ms", >>> + "dev_name", >>> + "dev", >>> + "parent_dev", >>> + "load_%", >>> + "old_freq_hz", >>> + "new_freq_hz"); >>> + seq_printf(s, "%-10s %-30s %-10s %-10s %-6s %-12s %-12s\n", >>> + "----------", >>> + "------------------------------", >>> + "----------", >>> + "----------", >>> + "----------", >>> + "------------", >>> + "------------"); >>> + >>> + spin_lock(&devfreq_debugfs_lock);> + for (count = 0; count < CONFIG_NR_DEVFREQ_TRANSITIONS; count++) { >>> + devfreq = debugfs_transitions[i].devfreq; >>> + freqs = &debugfs_transitions[i].freqs; >>> + load = debugfs_transitions[i].load; >>> + >>> + i = (CONFIG_NR_DEVFREQ_TRANSITIONS == ++i) ? 0 : i; >>> + if (!devfreq) >>> + continue; >>> + >>> +#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE) >>> + if (!strncmp(devfreq->governor_name, >>> + DEVFREQ_GOV_PASSIVE, DEVFREQ_NAME_LEN)) { >>> + struct devfreq_passive_data *data = devfreq->data; >>> + >>> + if (data) >>> + p_devfreq = data->parent; >>> + } else { >>> + p_devfreq = NULL; >>> + } >>> +#endif >>> + seq_printf(s, "%-10lld %-30s %-10s %-10s %-6ld %-12ld %-12ld\n", >>> + freqs->time, >>> + dev_name(devfreq->dev.parent), >>> + dev_name(&devfreq->dev), >>> + p_devfreq ? dev_name(&p_devfreq->dev) : "", >>> + load, >>> + freqs->old, >>> + freqs->new); >>> + } >>> + spin_unlock(&devfreq_debugfs_lock); >>> + >>> + return 0; >>> +} >>> +DEFINE_SHOW_ATTRIBUTE(devfreq_transitions); >>> + >>> static int __init devfreq_init(void) >>> { >>> devfreq_class = class_create(THIS_MODULE, "devfreq"); >>> @@ -1808,9 +1929,14 @@ static int __init devfreq_init(void) >>> devfreq_debugfs = NULL; >>> pr_warn("%s: couldn't create debugfs dir\n", __FILE__); >>> } else { >>> + spin_lock_init(&devfreq_debugfs_lock); >>> + >>> debugfs_create_file("devfreq_summary", 0444, >>> devfreq_debugfs, NULL, >>> &devfreq_summary_fops); >>> + debugfs_create_file("devfreq_transitions", 0444, >>> + devfreq_debugfs, NULL, >>> + &devfreq_transitions_fops); >>> } >>> >>> return 0; >>> diff --git a/drivers/devfreq/governor.h b/drivers/devfreq/governor.h >>> index dc7533ccc3db..01eecfdaf2d6 100644 >>> --- a/drivers/devfreq/governor.h >>> +++ b/drivers/devfreq/governor.h >>> @@ -68,6 +68,9 @@ extern int devfreq_add_governor(struct devfreq_governor *governor); >>> extern int devfreq_remove_governor(struct devfreq_governor *governor); >>> >>> extern int devfreq_update_status(struct devfreq *devfreq, unsigned long freq); >>> +extern void devfreq_update_transitions(struct devfreq *devfreq, >>> + unsigned long old_freq, unsigned long new_freq, >>> + unsigned long busy_time, unsigned long total_time); >> >> The 'extern' attribute isn't needed for function prototypes defined in >> header files. >> >> > > Right. I'll remove it. > >
08.01.2020 14:22, Chanwoo Choi пишет: > On 1/8/20 6:56 AM, Dmitry Osipenko wrote: >> 07.01.2020 12:05, Chanwoo Choi пишет: >>> Add new devfreq_transitions debugfs file to track the frequency transitions >>> of all devfreq devices for the simple profiling as following: >>> - /sys/kernel/debug/devfreq/devfreq_transitions >>> >>> And the user can decide the storage size (CONFIG_NR_DEVFREQ_TRANSITIONS) >>> in Kconfig in order to save the transition history. >>> >>> [Detailed description of each field of 'devfreq_transitions' debugfs file] >>> - time_ms : Change time of frequency transition. (unit: millisecond) >>> - dev_name : Device name of h/w. >>> - dev : Device name made by devfreq core. >>> - parent_dev : If devfreq device uses the passive governor, >>> show parent devfreq device name. >>> - load_% : If devfreq device uses the simple_ondemand governor, >>> load is used by governor whene deciding the new frequency. >>> (unit: percentage) >>> - old_freq_hz : Frequency before changing. (unit: hz) >>> - new_freq_hz : Frequency after changed. (unit: hz) >>> >>> [For example on Exynos5422-based Odroid-XU3 board] >>> $ cat /sys/kernel/debug/devfreq/devfreq_transitions >>> time_ms dev_name dev parent_dev load_% old_freq_hz new_freq_hz >>> ---------- ------------------------------ ---------- ---------- ---------- ------------ ------------ >>> 14600 soc:bus_noc devfreq2 devfreq1 0 100000000 67000000 >>> 14600 soc:bus_fsys_apb devfreq3 devfreq1 0 200000000 100000000 >>> 14600 soc:bus_fsys devfreq4 devfreq1 0 200000000 100000000 >>> 14600 soc:bus_fsys2 devfreq5 devfreq1 0 150000000 75000000 >>> 14602 soc:bus_mfc devfreq6 devfreq1 0 222000000 96000000 >>> 14602 soc:bus_gen devfreq7 devfreq1 0 267000000 89000000 >>> 14602 soc:bus_g2d devfreq9 devfreq1 0 300000000 84000000 >>> 14602 soc:bus_g2d_acp devfreq10 devfreq1 0 267000000 67000000 >>> 14602 soc:bus_jpeg devfreq11 devfreq1 0 300000000 75000000 >>> 14602 soc:bus_jpeg_apb devfreq12 devfreq1 0 167000000 84000000 >>> 14603 soc:bus_disp1_fimd devfreq13 devfreq1 0 200000000 120000000 >>> 14603 soc:bus_disp1 devfreq14 devfreq1 0 300000000 120000000 >>> 14606 soc:bus_gscl_scaler devfreq15 devfreq1 0 300000000 150000000 >>> 14606 soc:bus_mscl devfreq16 devfreq1 0 333000000 84000000 >>> 14608 soc:bus_wcore devfreq1 9 333000000 84000000 >>> 14783 10c20000.memory-controller devfreq0 35 825000000 633000000 >>> 15873 soc:bus_wcore devfreq1 41 84000000 400000000 >>> 15873 soc:bus_noc devfreq2 devfreq1 0 67000000 100000000 >>> [snip] >>> >>> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> >>> --- >>> drivers/devfreq/Kconfig | 13 +++ >>> drivers/devfreq/devfreq.c | 126 +++++++++++++++++++++++++++++ >>> drivers/devfreq/governor.h | 3 + >>> drivers/devfreq/governor_passive.c | 2 + >>> include/linux/devfreq.h | 1 + >>> 5 files changed, 145 insertions(+) >>> >>> diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig >>> index 0b1df12e0f21..84936eec0ef9 100644 >>> --- a/drivers/devfreq/Kconfig >>> +++ b/drivers/devfreq/Kconfig >>> @@ -74,6 +74,19 @@ config DEVFREQ_GOV_PASSIVE >>> through sysfs entries. The passive governor recommends that >>> devfreq device uses the OPP table to get the frequency/voltage. >>> >>> +comment "DEVFREQ Debugging" >>> + >>> +config NR_DEVFREQ_TRANSITIONS >>> + int "Maximum storage size to save DEVFREQ Transitions (10-1000)" >>> + depends on DEBUG_FS >>> + range 10 1000 >>> + default "100" >>> + help >>> + Show the frequency transitions of all devfreq devices via >>> + '/sys/kernel/debug/devfreq/devfreq_transitions' for the simple >>> + profiling. It needs to decide the storage size to save transition >>> + history of all devfreq devices. >>> + >>> comment "DEVFREQ Drivers" >>> >>> config ARM_EXYNOS_BUS_DEVFREQ >>> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c >>> index c7f5e4e06420..7abaae06fa65 100644 >>> --- a/drivers/devfreq/devfreq.c >>> +++ b/drivers/devfreq/devfreq.c >>> @@ -268,6 +268,57 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq) >>> } >>> EXPORT_SYMBOL(devfreq_update_status); >>> >>> +/** >>> + * devfreq_update_transitions() - Update frequency transitions for debugfs file >>> + * @devfreq: the devfreq instance >>> + * @old_freq: the previous frequency before changing the frequency >>> + * @new_freq: the new frequency after frequency is changed >>> + */ >>> +struct devfreq_transitions { >>> + struct devfreq *devfreq; >>> + struct devfreq_freqs freqs; >>> + unsigned long load; >>> +} debugfs_transitions[CONFIG_NR_DEVFREQ_TRANSITIONS]; >>> + >>> +static spinlock_t devfreq_debugfs_lock; >>> +static int debugfs_transitions_index; >>> + >>> +void devfreq_update_transitions(struct devfreq *devfreq, >>> + unsigned long old_freq, unsigned long new_freq, >>> + unsigned long busy_time, unsigned long total_time) >>> +{ >>> + unsigned long load; >>> + int i; >>> + >>> + if (!devfreq_debugfs || !devfreq || (old_freq == new_freq)) >>> + return; >>> + >>> + spin_lock_nested(&devfreq_debugfs_lock, SINGLE_DEPTH_NESTING); >>> + >>> + i = debugfs_transitions_index; >>> + >>> + /* >>> + * Calculate the load and if load is larger than 100, >>> + * initialize to 100 because the unit of load is percentage. >>> + */ >>> + load = (total_time == 0 ? 0 : (100 * busy_time) / total_time); >>> + if (load > 100) >>> + load = 100; >>> + >>> + debugfs_transitions[i].devfreq = devfreq; >>> + debugfs_transitions[i].freqs.time = ktime_to_ms(ktime_get()); >>> + debugfs_transitions[i].freqs.old = old_freq; >>> + debugfs_transitions[i].freqs.new = new_freq; >>> + debugfs_transitions[i].load = load; >>> + >>> + if (++i == CONFIG_NR_DEVFREQ_TRANSITIONS) >>> + i = 0; >>> + debugfs_transitions_index = i; >>> + >>> + spin_unlock(&devfreq_debugfs_lock); >>> +} >>> +EXPORT_SYMBOL(devfreq_update_transitions); >>> + >>> /** >>> * find_devfreq_governor() - Find devfreq governor from name >>> * @name: name of the governor >>> @@ -401,6 +452,10 @@ static int set_target(struct devfreq *devfreq, >>> return err; >>> } >>> >>> + devfreq_update_transitions(devfreq, cur_freq, new_freq, >>> + devfreq->last_status.busy_time, >>> + devfreq->last_status.total_time); >>> + >>> freqs.new = new_freq; >>> notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE); >>> >>> @@ -1787,6 +1842,72 @@ static int devfreq_summary_show(struct seq_file *s, void *data) >>> } >>> DEFINE_SHOW_ATTRIBUTE(devfreq_summary); >>> >>> +/** >>> + * devfreq_transitions_show() - Show the frequency transitions of the registered >>> + * devfreq devices via 'devfreq_transitions' debugfs file. >>> + */ >>> +static int devfreq_transitions_show(struct seq_file *s, void *data) >>> +{ >>> + struct devfreq *devfreq = NULL; >>> + struct devfreq *p_devfreq = NULL; >>> + struct devfreq_freqs *freqs = NULL; >>> + unsigned long load; >>> + int i = debugfs_transitions_index; >>> + int count; >>> + >>> + seq_printf(s, "%-10s %-30s %-10s %-10s %-6s %-12s %-12s\n", >>> + "time_ms", >>> + "dev_name", >>> + "dev", >>> + "parent_dev", >>> + "load_%", >>> + "old_freq_hz", >>> + "new_freq_hz"); >>> + seq_printf(s, "%-10s %-30s %-10s %-10s %-6s %-12s %-12s\n", >>> + "----------", >>> + "------------------------------", >>> + "----------", >>> + "----------", >>> + "----------", >>> + "------------", >>> + "------------"); >> >> Isn't this needed here? >> >> mutex_lock(&devfreq_list_lock); > > It doesn't touch the devfreq instance of devfreq_list. > So, it is not necessary locked of devfreq_list_lock. What stops devfreq device to be removed by another CPU thread while this function is in a process of execution? This condition is unlikely to happen in practice ever, but technically it should be possible to happen. >>> + spin_lock(&devfreq_debugfs_lock); >>> + for (count = 0; count < CONFIG_NR_DEVFREQ_TRANSITIONS; count++) { >>> + devfreq = debugfs_transitions[i].devfreq; >>> + freqs = &debugfs_transitions[i].freqs; >>> + load = debugfs_transitions[i].load; >>> + >>> + i = (CONFIG_NR_DEVFREQ_TRANSITIONS == ++i) ? 0 : i; >>> + if (!devfreq) >>> + continue; >> >> I suppose debugfs_transitions[i].devfreq should be set to NULL when >> devfreq device is removed, but I don't see it happening anywhere in this >> patch. > > When debugfs_transitions[] array is not fully filled out > by devfreq_update_transitions(), debugfs_transitions[i].devfreq is NULL. > In this case, if user execute 'cat /sys/kernel/debug/devfreq/devfreq_transitions', > devfreq_transitions_show() need to check the debugfs_transitions[i].devfreq > is NULL or not. > > After filled out the debugfs_transitions[] array, > actually, 'if(!devfreq)' is not necessary. Maybe, this style is inefficient > It need to rework. I'll think again. Imagine this situation: 1. there is a devfreq device, let's name it defreq123 2. the debugfs_transitions array is getting filled and now it has this entry: debugfs_transitions[0].devfreq = defreq123 3. user removes defreq123 driver module # rmmod defreq123 4. the defreq123 is released now 5. at what memory location debugfs_transitions[0].devfreq is pointing now?
08.01.2020 00:48, Bjorn Andersson пишет: > On Tue 07 Jan 01:05 PST 2020, Chanwoo Choi wrote: > >> Add new devfreq_transitions debugfs file to track the frequency transitions >> of all devfreq devices for the simple profiling as following: >> - /sys/kernel/debug/devfreq/devfreq_transitions >> >> And the user can decide the storage size (CONFIG_NR_DEVFREQ_TRANSITIONS) >> in Kconfig in order to save the transition history. >> >> [Detailed description of each field of 'devfreq_transitions' debugfs file] >> - time_ms : Change time of frequency transition. (unit: millisecond) >> - dev_name : Device name of h/w. >> - dev : Device name made by devfreq core. >> - parent_dev : If devfreq device uses the passive governor, >> show parent devfreq device name. >> - load_% : If devfreq device uses the simple_ondemand governor, >> load is used by governor whene deciding the new frequency. >> (unit: percentage) >> - old_freq_hz : Frequency before changing. (unit: hz) >> - new_freq_hz : Frequency after changed. (unit: hz) >> >> [For example on Exynos5422-based Odroid-XU3 board] >> $ cat /sys/kernel/debug/devfreq/devfreq_transitions >> time_ms dev_name dev parent_dev load_% old_freq_hz new_freq_hz >> ---------- ------------------------------ ---------- ---------- ---------- ------------ ------------ >> 14600 soc:bus_noc devfreq2 devfreq1 0 100000000 67000000 >> 14600 soc:bus_fsys_apb devfreq3 devfreq1 0 200000000 100000000 >> 14600 soc:bus_fsys devfreq4 devfreq1 0 200000000 100000000 >> 14600 soc:bus_fsys2 devfreq5 devfreq1 0 150000000 75000000 >> 14602 soc:bus_mfc devfreq6 devfreq1 0 222000000 96000000 >> 14602 soc:bus_gen devfreq7 devfreq1 0 267000000 89000000 >> 14602 soc:bus_g2d devfreq9 devfreq1 0 300000000 84000000 >> 14602 soc:bus_g2d_acp devfreq10 devfreq1 0 267000000 67000000 >> 14602 soc:bus_jpeg devfreq11 devfreq1 0 300000000 75000000 >> 14602 soc:bus_jpeg_apb devfreq12 devfreq1 0 167000000 84000000 >> 14603 soc:bus_disp1_fimd devfreq13 devfreq1 0 200000000 120000000 >> 14603 soc:bus_disp1 devfreq14 devfreq1 0 300000000 120000000 >> 14606 soc:bus_gscl_scaler devfreq15 devfreq1 0 300000000 150000000 >> 14606 soc:bus_mscl devfreq16 devfreq1 0 333000000 84000000 >> 14608 soc:bus_wcore devfreq1 9 333000000 84000000 >> 14783 10c20000.memory-controller devfreq0 35 825000000 633000000 >> 15873 soc:bus_wcore devfreq1 41 84000000 400000000 >> 15873 soc:bus_noc devfreq2 devfreq1 0 67000000 100000000 >> [snip] >> > > Wouldn't it make more sense to expose this through the tracing > framework - like many other subsystems does? I think devfreq core already has some tracing support and indeed it should be better to extend it rather than duplicate.
08.01.2020 15:01, Chanwoo Choi пишет: > On 1/8/20 7:56 PM, Chanwoo Choi wrote: >> Hi, >> >> On 1/8/20 6:31 AM, Dmitry Osipenko wrote: >>> Hello Chanwoo, >>> >>> 07.01.2020 12:05, Chanwoo Choi пишет: >>>> Add new devfreq_transitions debugfs file to track the frequency transitions >>>> of all devfreq devices for the simple profiling as following: >>>> - /sys/kernel/debug/devfreq/devfreq_transitions >>>> >>>> And the user can decide the storage size (CONFIG_NR_DEVFREQ_TRANSITIONS) >>>> in Kconfig in order to save the transition history. >>>> >>>> [Detailed description of each field of 'devfreq_transitions' debugfs file] >>>> - time_ms : Change time of frequency transition. (unit: millisecond) >>>> - dev_name : Device name of h/w. >>>> - dev : Device name made by devfreq core. >>>> - parent_dev : If devfreq device uses the passive governor, >>>> show parent devfreq device name. >>>> - load_% : If devfreq device uses the simple_ondemand governor, >>>> load is used by governor whene deciding the new frequency. >>>> (unit: percentage) >>>> - old_freq_hz : Frequency before changing. (unit: hz) >>>> - new_freq_hz : Frequency after changed. (unit: hz) >>>> >>>> [For example on Exynos5422-based Odroid-XU3 board] >>>> $ cat /sys/kernel/debug/devfreq/devfreq_transitions >>>> time_ms dev_name dev parent_dev load_% old_freq_hz new_freq_hz >>>> ---------- ------------------------------ ---------- ---------- ---------- ------------ ------------ >>>> 14600 soc:bus_noc devfreq2 devfreq1 0 100000000 67000000 >>>> 14600 soc:bus_fsys_apb devfreq3 devfreq1 0 200000000 100000000 >>>> 14600 soc:bus_fsys devfreq4 devfreq1 0 200000000 100000000 >>>> 14600 soc:bus_fsys2 devfreq5 devfreq1 0 150000000 75000000 >>>> 14602 soc:bus_mfc devfreq6 devfreq1 0 222000000 96000000 >>>> 14602 soc:bus_gen devfreq7 devfreq1 0 267000000 89000000 >>>> 14602 soc:bus_g2d devfreq9 devfreq1 0 300000000 84000000 >>>> 14602 soc:bus_g2d_acp devfreq10 devfreq1 0 267000000 67000000 >>>> 14602 soc:bus_jpeg devfreq11 devfreq1 0 300000000 75000000 >>>> 14602 soc:bus_jpeg_apb devfreq12 devfreq1 0 167000000 84000000 >>>> 14603 soc:bus_disp1_fimd devfreq13 devfreq1 0 200000000 120000000 >>>> 14603 soc:bus_disp1 devfreq14 devfreq1 0 300000000 120000000 >>>> 14606 soc:bus_gscl_scaler devfreq15 devfreq1 0 300000000 150000000 >>>> 14606 soc:bus_mscl devfreq16 devfreq1 0 333000000 84000000 >>>> 14608 soc:bus_wcore devfreq1 9 333000000 84000000 >>>> 14783 10c20000.memory-controller devfreq0 35 825000000 633000000 >>>> 15873 soc:bus_wcore devfreq1 41 84000000 400000000 >>>> 15873 soc:bus_noc devfreq2 devfreq1 0 67000000 100000000 >>>> [snip] >>>> >>>> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> >>>> --- >>>> drivers/devfreq/Kconfig | 13 +++ >>>> drivers/devfreq/devfreq.c | 126 +++++++++++++++++++++++++++++ >>>> drivers/devfreq/governor.h | 3 + >>>> drivers/devfreq/governor_passive.c | 2 + >>>> include/linux/devfreq.h | 1 + >>>> 5 files changed, 145 insertions(+) >>>> >>>> diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig >>>> index 0b1df12e0f21..84936eec0ef9 100644 >>>> --- a/drivers/devfreq/Kconfig >>>> +++ b/drivers/devfreq/Kconfig >>>> @@ -74,6 +74,19 @@ config DEVFREQ_GOV_PASSIVE >>>> through sysfs entries. The passive governor recommends that >>>> devfreq device uses the OPP table to get the frequency/voltage. >>>> >>>> +comment "DEVFREQ Debugging" >>>> + >>>> +config NR_DEVFREQ_TRANSITIONS >>>> + int "Maximum storage size to save DEVFREQ Transitions (10-1000)" >>>> + depends on DEBUG_FS >>>> + range 10 1000 >>>> + default "100" >>>> + help >>>> + Show the frequency transitions of all devfreq devices via >>>> + '/sys/kernel/debug/devfreq/devfreq_transitions' for the simple >>>> + profiling. It needs to decide the storage size to save transition >>>> + history of all devfreq devices. >>>> + >>>> comment "DEVFREQ Drivers" >>>> >>>> config ARM_EXYNOS_BUS_DEVFREQ >>>> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c >>>> index c7f5e4e06420..7abaae06fa65 100644 >>>> --- a/drivers/devfreq/devfreq.c >>>> +++ b/drivers/devfreq/devfreq.c >>>> @@ -268,6 +268,57 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq) >>>> } >>>> EXPORT_SYMBOL(devfreq_update_status); >>>> +/** >>>> + * devfreq_update_transitions() - Update frequency transitions for debugfs file >>>> + * @devfreq: the devfreq instance >>>> + * @old_freq: the previous frequency before changing the frequency >>>> + * @new_freq: the new frequency after frequency is changed >>>> + */ >>>> +struct devfreq_transitions { >>>> + struct devfreq *devfreq; >>>> + struct devfreq_freqs freqs; >>>> + unsigned long load; >>>> +} debugfs_transitions[CONFIG_NR_DEVFREQ_TRANSITIONS]; >>>> + >>>> +static spinlock_t devfreq_debugfs_lock; >>> >>> This could be: >>> >>> static DEFINE_SPINLOCK(devfreq_debugfs_lock); >>> >>> and then spin_lock_init() isn't needed. >> >> OK >> >>> >>> >>> Also, The "<linux/spinlock.h>" should be included directly by devfreq.c >> >> OK. >> >>> >>>> +static int debugfs_transitions_index; >>>> + >>>> +void devfreq_update_transitions(struct devfreq *devfreq, >>>> + unsigned long old_freq, unsigned long new_freq, >>>> + unsigned long busy_time, unsigned long total_time) >>>> +{ >>>> + unsigned long load; >>>> + int i; >>>> + >>>> + if (!devfreq_debugfs || !devfreq || (old_freq == new_freq)) >>>> + return; >>>> + >>>> + spin_lock_nested(&devfreq_debugfs_lock, SINGLE_DEPTH_NESTING); >>>> + >>>> + i = debugfs_transitions_index; >>>> + >>>> + /* >>>> + * Calculate the load and if load is larger than 100, >>>> + * initialize to 100 because the unit of load is percentage. >>>> + */ >>>> + load = (total_time == 0 ? 0 : (100 * busy_time) / total_time); >>>> + if (load > 100) >>>> + load = 100; >>>> + >>>> + debugfs_transitions[i].devfreq = devfreq; >>>> + debugfs_transitions[i].freqs.time = ktime_to_ms(ktime_get()); >>>> + debugfs_transitions[i].freqs.old = old_freq; >>>> + debugfs_transitions[i].freqs.new = new_freq; >>>> + debugfs_transitions[i].load = load; >>>> + >>>> + if (++i == CONFIG_NR_DEVFREQ_TRANSITIONS) >>>> + i = 0; >>>> + debugfs_transitions_index = i; >>>> + >>>> + spin_unlock(&devfreq_debugfs_lock); >>>> +} >>>> +EXPORT_SYMBOL(devfreq_update_transitions); >>> >>> What about EXPORT_SYMBOL_GPL()? >> >> I'll remove it. > > Ah. It is needed to support module build. > it is used by passive governor. My point was about the "GPL" part. The EXPORT_SYMBOL_GPL() prohibits closed source drivers to use the exported API.
Hi, On 1/8/20 2:20 PM, Dmitry Osipenko wrote: > 08.01.2020 00:48, Bjorn Andersson пишет: >> On Tue 07 Jan 01:05 PST 2020, Chanwoo Choi wrote: >> >>> Add new devfreq_transitions debugfs file to track the frequency transitions >>> of all devfreq devices for the simple profiling as following: >>> - /sys/kernel/debug/devfreq/devfreq_transitions >>> >>> And the user can decide the storage size (CONFIG_NR_DEVFREQ_TRANSITIONS) >>> in Kconfig in order to save the transition history. >>> >>> [Detailed description of each field of 'devfreq_transitions' debugfs file] >>> - time_ms : Change time of frequency transition. (unit: millisecond) >>> - dev_name : Device name of h/w. >>> - dev : Device name made by devfreq core. >>> - parent_dev : If devfreq device uses the passive governor, >>> show parent devfreq device name. >>> - load_% : If devfreq device uses the simple_ondemand governor, >>> load is used by governor whene deciding the new frequency. >>> (unit: percentage) >>> - old_freq_hz : Frequency before changing. (unit: hz) >>> - new_freq_hz : Frequency after changed. (unit: hz) >>> >>> [For example on Exynos5422-based Odroid-XU3 board] >>> $ cat /sys/kernel/debug/devfreq/devfreq_transitions >>> time_ms dev_name dev parent_dev load_% old_freq_hz new_freq_hz >>> ---------- ------------------------------ ---------- ---------- ---------- ------------ ------------ >>> 14600 soc:bus_noc devfreq2 devfreq1 0 100000000 67000000 >>> 14600 soc:bus_fsys_apb devfreq3 devfreq1 0 200000000 100000000 >>> 14600 soc:bus_fsys devfreq4 devfreq1 0 200000000 100000000 >>> 14600 soc:bus_fsys2 devfreq5 devfreq1 0 150000000 75000000 >>> 14602 soc:bus_mfc devfreq6 devfreq1 0 222000000 96000000 >>> 14602 soc:bus_gen devfreq7 devfreq1 0 267000000 89000000 >>> 14602 soc:bus_g2d devfreq9 devfreq1 0 300000000 84000000 >>> 14602 soc:bus_g2d_acp devfreq10 devfreq1 0 267000000 67000000 >>> 14602 soc:bus_jpeg devfreq11 devfreq1 0 300000000 75000000 >>> 14602 soc:bus_jpeg_apb devfreq12 devfreq1 0 167000000 84000000 >>> 14603 soc:bus_disp1_fimd devfreq13 devfreq1 0 200000000 120000000 >>> 14603 soc:bus_disp1 devfreq14 devfreq1 0 300000000 120000000 >>> 14606 soc:bus_gscl_scaler devfreq15 devfreq1 0 300000000 150000000 >>> 14606 soc:bus_mscl devfreq16 devfreq1 0 333000000 84000000 >>> 14608 soc:bus_wcore devfreq1 9 333000000 84000000 >>> 14783 10c20000.memory-controller devfreq0 35 825000000 633000000 >>> 15873 soc:bus_wcore devfreq1 41 84000000 400000000 >>> 15873 soc:bus_noc devfreq2 devfreq1 0 67000000 100000000 >>> [snip] >>> >> >> Wouldn't it make more sense to expose this through the tracing >> framework - like many other subsystems does? > > I think devfreq core already has some tracing support and indeed it > should be better to extend it rather than duplicate. > In my opinion this debugfs interface should be considered as a helpful validation entry point. We had some issues with wrong bootloader configurations in clock tree, where some frequencies could not be set in the kernel. Similar useful description can be find in clock subsystem where there is clock tree summary file. It is much cheaper to poke a few files in debug dir by some automated test than starting tracing, provoking desired code flow in the devfreq for every device, paring the results... A simple boot test which reads only these new files can be enough to rise the flag. Secondly the tracing is not always compiled. It could capture old/wrong bootloaders which pinned devices improperly to PLLs or wrong DT values in OPP table. (a workaround for Odroid xu4 patchset: https://lkml.org/lkml/2019/7/15/276 ) Chanwoo what do think about some sanity check summary? It could be presented in a 3rd file: 'devfreq_sanity', which could report if the devices could set their registered OPPs and got the same values, i.e. set 166MHz --> set to 150MHz in reality. If a config option i.e. DEVFREQ_SANITY is set then during the registration of a new device it checks OPPs if they are possible to set. It could be done before assigning the governor for the device and results present in of of your files. Regards, Lukasz
On 1/8/20 11:23 PM, Dmitry Osipenko wrote: > 08.01.2020 15:01, Chanwoo Choi пишет: >> On 1/8/20 7:56 PM, Chanwoo Choi wrote: >>> Hi, >>> >>> On 1/8/20 6:31 AM, Dmitry Osipenko wrote: >>>> Hello Chanwoo, >>>> >>>> 07.01.2020 12:05, Chanwoo Choi пишет: >>>>> Add new devfreq_transitions debugfs file to track the frequency transitions >>>>> of all devfreq devices for the simple profiling as following: >>>>> - /sys/kernel/debug/devfreq/devfreq_transitions >>>>> >>>>> And the user can decide the storage size (CONFIG_NR_DEVFREQ_TRANSITIONS) >>>>> in Kconfig in order to save the transition history. >>>>> >>>>> [Detailed description of each field of 'devfreq_transitions' debugfs file] >>>>> - time_ms : Change time of frequency transition. (unit: millisecond) >>>>> - dev_name : Device name of h/w. >>>>> - dev : Device name made by devfreq core. >>>>> - parent_dev : If devfreq device uses the passive governor, >>>>> show parent devfreq device name. >>>>> - load_% : If devfreq device uses the simple_ondemand governor, >>>>> load is used by governor whene deciding the new frequency. >>>>> (unit: percentage) >>>>> - old_freq_hz : Frequency before changing. (unit: hz) >>>>> - new_freq_hz : Frequency after changed. (unit: hz) >>>>> >>>>> [For example on Exynos5422-based Odroid-XU3 board] >>>>> $ cat /sys/kernel/debug/devfreq/devfreq_transitions >>>>> time_ms dev_name dev parent_dev load_% old_freq_hz new_freq_hz >>>>> ---------- ------------------------------ ---------- ---------- ---------- ------------ ------------ >>>>> 14600 soc:bus_noc devfreq2 devfreq1 0 100000000 67000000 >>>>> 14600 soc:bus_fsys_apb devfreq3 devfreq1 0 200000000 100000000 >>>>> 14600 soc:bus_fsys devfreq4 devfreq1 0 200000000 100000000 >>>>> 14600 soc:bus_fsys2 devfreq5 devfreq1 0 150000000 75000000 >>>>> 14602 soc:bus_mfc devfreq6 devfreq1 0 222000000 96000000 >>>>> 14602 soc:bus_gen devfreq7 devfreq1 0 267000000 89000000 >>>>> 14602 soc:bus_g2d devfreq9 devfreq1 0 300000000 84000000 >>>>> 14602 soc:bus_g2d_acp devfreq10 devfreq1 0 267000000 67000000 >>>>> 14602 soc:bus_jpeg devfreq11 devfreq1 0 300000000 75000000 >>>>> 14602 soc:bus_jpeg_apb devfreq12 devfreq1 0 167000000 84000000 >>>>> 14603 soc:bus_disp1_fimd devfreq13 devfreq1 0 200000000 120000000 >>>>> 14603 soc:bus_disp1 devfreq14 devfreq1 0 300000000 120000000 >>>>> 14606 soc:bus_gscl_scaler devfreq15 devfreq1 0 300000000 150000000 >>>>> 14606 soc:bus_mscl devfreq16 devfreq1 0 333000000 84000000 >>>>> 14608 soc:bus_wcore devfreq1 9 333000000 84000000 >>>>> 14783 10c20000.memory-controller devfreq0 35 825000000 633000000 >>>>> 15873 soc:bus_wcore devfreq1 41 84000000 400000000 >>>>> 15873 soc:bus_noc devfreq2 devfreq1 0 67000000 100000000 >>>>> [snip] >>>>> >>>>> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> >>>>> --- >>>>> drivers/devfreq/Kconfig | 13 +++ >>>>> drivers/devfreq/devfreq.c | 126 +++++++++++++++++++++++++++++ >>>>> drivers/devfreq/governor.h | 3 + >>>>> drivers/devfreq/governor_passive.c | 2 + >>>>> include/linux/devfreq.h | 1 + >>>>> 5 files changed, 145 insertions(+) >>>>> >>>>> diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig >>>>> index 0b1df12e0f21..84936eec0ef9 100644 >>>>> --- a/drivers/devfreq/Kconfig >>>>> +++ b/drivers/devfreq/Kconfig >>>>> @@ -74,6 +74,19 @@ config DEVFREQ_GOV_PASSIVE >>>>> through sysfs entries. The passive governor recommends that >>>>> devfreq device uses the OPP table to get the frequency/voltage. >>>>> >>>>> +comment "DEVFREQ Debugging" >>>>> + >>>>> +config NR_DEVFREQ_TRANSITIONS >>>>> + int "Maximum storage size to save DEVFREQ Transitions (10-1000)" >>>>> + depends on DEBUG_FS >>>>> + range 10 1000 >>>>> + default "100" >>>>> + help >>>>> + Show the frequency transitions of all devfreq devices via >>>>> + '/sys/kernel/debug/devfreq/devfreq_transitions' for the simple >>>>> + profiling. It needs to decide the storage size to save transition >>>>> + history of all devfreq devices. >>>>> + >>>>> comment "DEVFREQ Drivers" >>>>> >>>>> config ARM_EXYNOS_BUS_DEVFREQ >>>>> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c >>>>> index c7f5e4e06420..7abaae06fa65 100644 >>>>> --- a/drivers/devfreq/devfreq.c >>>>> +++ b/drivers/devfreq/devfreq.c >>>>> @@ -268,6 +268,57 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq) >>>>> } >>>>> EXPORT_SYMBOL(devfreq_update_status); >>>>> +/** >>>>> + * devfreq_update_transitions() - Update frequency transitions for debugfs file >>>>> + * @devfreq: the devfreq instance >>>>> + * @old_freq: the previous frequency before changing the frequency >>>>> + * @new_freq: the new frequency after frequency is changed >>>>> + */ >>>>> +struct devfreq_transitions { >>>>> + struct devfreq *devfreq; >>>>> + struct devfreq_freqs freqs; >>>>> + unsigned long load; >>>>> +} debugfs_transitions[CONFIG_NR_DEVFREQ_TRANSITIONS]; >>>>> + >>>>> +static spinlock_t devfreq_debugfs_lock; >>>> >>>> This could be: >>>> >>>> static DEFINE_SPINLOCK(devfreq_debugfs_lock); >>>> >>>> and then spin_lock_init() isn't needed. >>> >>> OK >>> >>>> >>>> >>>> Also, The "<linux/spinlock.h>" should be included directly by devfreq.c >>> >>> OK. >>> >>>> >>>>> +static int debugfs_transitions_index; >>>>> + >>>>> +void devfreq_update_transitions(struct devfreq *devfreq, >>>>> + unsigned long old_freq, unsigned long new_freq, >>>>> + unsigned long busy_time, unsigned long total_time) >>>>> +{ >>>>> + unsigned long load; >>>>> + int i; >>>>> + >>>>> + if (!devfreq_debugfs || !devfreq || (old_freq == new_freq)) >>>>> + return; >>>>> + >>>>> + spin_lock_nested(&devfreq_debugfs_lock, SINGLE_DEPTH_NESTING); >>>>> + >>>>> + i = debugfs_transitions_index; >>>>> + >>>>> + /* >>>>> + * Calculate the load and if load is larger than 100, >>>>> + * initialize to 100 because the unit of load is percentage. >>>>> + */ >>>>> + load = (total_time == 0 ? 0 : (100 * busy_time) / total_time); >>>>> + if (load > 100) >>>>> + load = 100; >>>>> + >>>>> + debugfs_transitions[i].devfreq = devfreq; >>>>> + debugfs_transitions[i].freqs.time = ktime_to_ms(ktime_get()); >>>>> + debugfs_transitions[i].freqs.old = old_freq; >>>>> + debugfs_transitions[i].freqs.new = new_freq; >>>>> + debugfs_transitions[i].load = load; >>>>> + >>>>> + if (++i == CONFIG_NR_DEVFREQ_TRANSITIONS) >>>>> + i = 0; >>>>> + debugfs_transitions_index = i; >>>>> + >>>>> + spin_unlock(&devfreq_debugfs_lock); >>>>> +} >>>>> +EXPORT_SYMBOL(devfreq_update_transitions); >>>> >>>> What about EXPORT_SYMBOL_GPL()? >>> >>> I'll remove it. >> >> Ah. It is needed to support module build. >> it is used by passive governor. > > My point was about the "GPL" part. The EXPORT_SYMBOL_GPL() prohibits > closed source drivers to use the exported API. I'm sorry of my misunderstanding. OK. I'll use EXPORT_SYMBOL_GPL()
Hi Bjorn and Dmitry, I replied from Bjorn and Dmitry opinion. On 1/8/20 11:20 PM, Dmitry Osipenko wrote: > 08.01.2020 00:48, Bjorn Andersson пишет: >> On Tue 07 Jan 01:05 PST 2020, Chanwoo Choi wrote: >> >>> Add new devfreq_transitions debugfs file to track the frequency transitions >>> of all devfreq devices for the simple profiling as following: >>> - /sys/kernel/debug/devfreq/devfreq_transitions >>> >>> And the user can decide the storage size (CONFIG_NR_DEVFREQ_TRANSITIONS) >>> in Kconfig in order to save the transition history. >>> >>> [Detailed description of each field of 'devfreq_transitions' debugfs file] >>> - time_ms : Change time of frequency transition. (unit: millisecond) >>> - dev_name : Device name of h/w. >>> - dev : Device name made by devfreq core. >>> - parent_dev : If devfreq device uses the passive governor, >>> show parent devfreq device name. >>> - load_% : If devfreq device uses the simple_ondemand governor, >>> load is used by governor whene deciding the new frequency. >>> (unit: percentage) >>> - old_freq_hz : Frequency before changing. (unit: hz) >>> - new_freq_hz : Frequency after changed. (unit: hz) >>> >>> [For example on Exynos5422-based Odroid-XU3 board] >>> $ cat /sys/kernel/debug/devfreq/devfreq_transitions >>> time_ms dev_name dev parent_dev load_% old_freq_hz new_freq_hz >>> ---------- ------------------------------ ---------- ---------- ---------- ------------ ------------ >>> 14600 soc:bus_noc devfreq2 devfreq1 0 100000000 67000000 >>> 14600 soc:bus_fsys_apb devfreq3 devfreq1 0 200000000 100000000 >>> 14600 soc:bus_fsys devfreq4 devfreq1 0 200000000 100000000 >>> 14600 soc:bus_fsys2 devfreq5 devfreq1 0 150000000 75000000 >>> 14602 soc:bus_mfc devfreq6 devfreq1 0 222000000 96000000 >>> 14602 soc:bus_gen devfreq7 devfreq1 0 267000000 89000000 >>> 14602 soc:bus_g2d devfreq9 devfreq1 0 300000000 84000000 >>> 14602 soc:bus_g2d_acp devfreq10 devfreq1 0 267000000 67000000 >>> 14602 soc:bus_jpeg devfreq11 devfreq1 0 300000000 75000000 >>> 14602 soc:bus_jpeg_apb devfreq12 devfreq1 0 167000000 84000000 >>> 14603 soc:bus_disp1_fimd devfreq13 devfreq1 0 200000000 120000000 >>> 14603 soc:bus_disp1 devfreq14 devfreq1 0 300000000 120000000 >>> 14606 soc:bus_gscl_scaler devfreq15 devfreq1 0 300000000 150000000 >>> 14606 soc:bus_mscl devfreq16 devfreq1 0 333000000 84000000 >>> 14608 soc:bus_wcore devfreq1 9 333000000 84000000 >>> 14783 10c20000.memory-controller devfreq0 35 825000000 633000000 >>> 15873 soc:bus_wcore devfreq1 41 84000000 400000000 >>> 15873 soc:bus_noc devfreq2 devfreq1 0 67000000 100000000 >>> [snip] >>> >> >> Wouldn't it make more sense to expose this through the tracing >> framework - like many other subsystems does? > > I think devfreq core already has some tracing support and indeed it > should be better to extend it rather than duplicate. > First of all, thanks for comments. Before developing it, I have considered what is better to support debugging features for devfreq device. As you commented, trace event is more general way to catch the detailed behavior. But, I hope to provide the very easy simple profiling way for user if it is not harmful to the principle of linux kernel. In order to prevent the performance regression when DEBUG_FS is enabled, I will add the CONFIG_DEVFREQ_TRANSITIONS_DEBUG for 'devfreq_transitions' to make it selectable.
On 1/8/20 11:10 PM, Dmitry Osipenko wrote: > 08.01.2020 14:22, Chanwoo Choi пишет: >> On 1/8/20 6:56 AM, Dmitry Osipenko wrote: >>> 07.01.2020 12:05, Chanwoo Choi пишет: >>>> Add new devfreq_transitions debugfs file to track the frequency transitions >>>> of all devfreq devices for the simple profiling as following: >>>> - /sys/kernel/debug/devfreq/devfreq_transitions >>>> >>>> And the user can decide the storage size (CONFIG_NR_DEVFREQ_TRANSITIONS) >>>> in Kconfig in order to save the transition history. >>>> >>>> [Detailed description of each field of 'devfreq_transitions' debugfs file] >>>> - time_ms : Change time of frequency transition. (unit: millisecond) >>>> - dev_name : Device name of h/w. >>>> - dev : Device name made by devfreq core. >>>> - parent_dev : If devfreq device uses the passive governor, >>>> show parent devfreq device name. >>>> - load_% : If devfreq device uses the simple_ondemand governor, >>>> load is used by governor whene deciding the new frequency. >>>> (unit: percentage) >>>> - old_freq_hz : Frequency before changing. (unit: hz) >>>> - new_freq_hz : Frequency after changed. (unit: hz) >>>> >>>> [For example on Exynos5422-based Odroid-XU3 board] >>>> $ cat /sys/kernel/debug/devfreq/devfreq_transitions >>>> time_ms dev_name dev parent_dev load_% old_freq_hz new_freq_hz >>>> ---------- ------------------------------ ---------- ---------- ---------- ------------ ------------ >>>> 14600 soc:bus_noc devfreq2 devfreq1 0 100000000 67000000 >>>> 14600 soc:bus_fsys_apb devfreq3 devfreq1 0 200000000 100000000 >>>> 14600 soc:bus_fsys devfreq4 devfreq1 0 200000000 100000000 >>>> 14600 soc:bus_fsys2 devfreq5 devfreq1 0 150000000 75000000 >>>> 14602 soc:bus_mfc devfreq6 devfreq1 0 222000000 96000000 >>>> 14602 soc:bus_gen devfreq7 devfreq1 0 267000000 89000000 >>>> 14602 soc:bus_g2d devfreq9 devfreq1 0 300000000 84000000 >>>> 14602 soc:bus_g2d_acp devfreq10 devfreq1 0 267000000 67000000 >>>> 14602 soc:bus_jpeg devfreq11 devfreq1 0 300000000 75000000 >>>> 14602 soc:bus_jpeg_apb devfreq12 devfreq1 0 167000000 84000000 >>>> 14603 soc:bus_disp1_fimd devfreq13 devfreq1 0 200000000 120000000 >>>> 14603 soc:bus_disp1 devfreq14 devfreq1 0 300000000 120000000 >>>> 14606 soc:bus_gscl_scaler devfreq15 devfreq1 0 300000000 150000000 >>>> 14606 soc:bus_mscl devfreq16 devfreq1 0 333000000 84000000 >>>> 14608 soc:bus_wcore devfreq1 9 333000000 84000000 >>>> 14783 10c20000.memory-controller devfreq0 35 825000000 633000000 >>>> 15873 soc:bus_wcore devfreq1 41 84000000 400000000 >>>> 15873 soc:bus_noc devfreq2 devfreq1 0 67000000 100000000 >>>> [snip] >>>> >>>> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> >>>> --- >>>> drivers/devfreq/Kconfig | 13 +++ >>>> drivers/devfreq/devfreq.c | 126 +++++++++++++++++++++++++++++ >>>> drivers/devfreq/governor.h | 3 + >>>> drivers/devfreq/governor_passive.c | 2 + >>>> include/linux/devfreq.h | 1 + >>>> 5 files changed, 145 insertions(+) >>>> >>>> diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig >>>> index 0b1df12e0f21..84936eec0ef9 100644 >>>> --- a/drivers/devfreq/Kconfig >>>> +++ b/drivers/devfreq/Kconfig >>>> @@ -74,6 +74,19 @@ config DEVFREQ_GOV_PASSIVE >>>> through sysfs entries. The passive governor recommends that >>>> devfreq device uses the OPP table to get the frequency/voltage. >>>> >>>> +comment "DEVFREQ Debugging" >>>> + >>>> +config NR_DEVFREQ_TRANSITIONS >>>> + int "Maximum storage size to save DEVFREQ Transitions (10-1000)" >>>> + depends on DEBUG_FS >>>> + range 10 1000 >>>> + default "100" >>>> + help >>>> + Show the frequency transitions of all devfreq devices via >>>> + '/sys/kernel/debug/devfreq/devfreq_transitions' for the simple >>>> + profiling. It needs to decide the storage size to save transition >>>> + history of all devfreq devices. >>>> + >>>> comment "DEVFREQ Drivers" >>>> >>>> config ARM_EXYNOS_BUS_DEVFREQ >>>> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c >>>> index c7f5e4e06420..7abaae06fa65 100644 >>>> --- a/drivers/devfreq/devfreq.c >>>> +++ b/drivers/devfreq/devfreq.c >>>> @@ -268,6 +268,57 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq) >>>> } >>>> EXPORT_SYMBOL(devfreq_update_status); >>>> >>>> +/** >>>> + * devfreq_update_transitions() - Update frequency transitions for debugfs file >>>> + * @devfreq: the devfreq instance >>>> + * @old_freq: the previous frequency before changing the frequency >>>> + * @new_freq: the new frequency after frequency is changed >>>> + */ >>>> +struct devfreq_transitions { >>>> + struct devfreq *devfreq; >>>> + struct devfreq_freqs freqs; >>>> + unsigned long load; >>>> +} debugfs_transitions[CONFIG_NR_DEVFREQ_TRANSITIONS]; >>>> + >>>> +static spinlock_t devfreq_debugfs_lock; >>>> +static int debugfs_transitions_index; >>>> + >>>> +void devfreq_update_transitions(struct devfreq *devfreq, >>>> + unsigned long old_freq, unsigned long new_freq, >>>> + unsigned long busy_time, unsigned long total_time) >>>> +{ >>>> + unsigned long load; >>>> + int i; >>>> + >>>> + if (!devfreq_debugfs || !devfreq || (old_freq == new_freq)) >>>> + return; >>>> + >>>> + spin_lock_nested(&devfreq_debugfs_lock, SINGLE_DEPTH_NESTING); >>>> + >>>> + i = debugfs_transitions_index; >>>> + >>>> + /* >>>> + * Calculate the load and if load is larger than 100, >>>> + * initialize to 100 because the unit of load is percentage. >>>> + */ >>>> + load = (total_time == 0 ? 0 : (100 * busy_time) / total_time); >>>> + if (load > 100) >>>> + load = 100; >>>> + >>>> + debugfs_transitions[i].devfreq = devfreq; >>>> + debugfs_transitions[i].freqs.time = ktime_to_ms(ktime_get()); >>>> + debugfs_transitions[i].freqs.old = old_freq; >>>> + debugfs_transitions[i].freqs.new = new_freq; >>>> + debugfs_transitions[i].load = load; >>>> + >>>> + if (++i == CONFIG_NR_DEVFREQ_TRANSITIONS) >>>> + i = 0; >>>> + debugfs_transitions_index = i; >>>> + >>>> + spin_unlock(&devfreq_debugfs_lock); >>>> +} >>>> +EXPORT_SYMBOL(devfreq_update_transitions); >>>> + >>>> /** >>>> * find_devfreq_governor() - Find devfreq governor from name >>>> * @name: name of the governor >>>> @@ -401,6 +452,10 @@ static int set_target(struct devfreq *devfreq, >>>> return err; >>>> } >>>> >>>> + devfreq_update_transitions(devfreq, cur_freq, new_freq, >>>> + devfreq->last_status.busy_time, >>>> + devfreq->last_status.total_time); >>>> + >>>> freqs.new = new_freq; >>>> notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE); >>>> >>>> @@ -1787,6 +1842,72 @@ static int devfreq_summary_show(struct seq_file *s, void *data) >>>> } >>>> DEFINE_SHOW_ATTRIBUTE(devfreq_summary); >>>> >>>> +/** >>>> + * devfreq_transitions_show() - Show the frequency transitions of the registered >>>> + * devfreq devices via 'devfreq_transitions' debugfs file. >>>> + */ >>>> +static int devfreq_transitions_show(struct seq_file *s, void *data) >>>> +{ >>>> + struct devfreq *devfreq = NULL; >>>> + struct devfreq *p_devfreq = NULL; >>>> + struct devfreq_freqs *freqs = NULL; >>>> + unsigned long load; >>>> + int i = debugfs_transitions_index; >>>> + int count; >>>> + >>>> + seq_printf(s, "%-10s %-30s %-10s %-10s %-6s %-12s %-12s\n", >>>> + "time_ms", >>>> + "dev_name", >>>> + "dev", >>>> + "parent_dev", >>>> + "load_%", >>>> + "old_freq_hz", >>>> + "new_freq_hz"); >>>> + seq_printf(s, "%-10s %-30s %-10s %-10s %-6s %-12s %-12s\n", >>>> + "----------", >>>> + "------------------------------", >>>> + "----------", >>>> + "----------", >>>> + "----------", >>>> + "------------", >>>> + "------------"); >>> >>> Isn't this needed here? >>> >>> mutex_lock(&devfreq_list_lock); >> >> It doesn't touch the devfreq instance of devfreq_list. >> So, it is not necessary locked of devfreq_list_lock. > > What stops devfreq device to be removed by another CPU thread while this > function is in a process of execution? > > This condition is unlikely to happen in practice ever, but technically > it should be possible to happen. > >>>> + spin_lock(&devfreq_debugfs_lock); >>>> + for (count = 0; count < CONFIG_NR_DEVFREQ_TRANSITIONS; count++) { >>>> + devfreq = debugfs_transitions[i].devfreq; >>>> + freqs = &debugfs_transitions[i].freqs; >>>> + load = debugfs_transitions[i].load; >>>> + >>>> + i = (CONFIG_NR_DEVFREQ_TRANSITIONS == ++i) ? 0 : i; >>>> + if (!devfreq) >>>> + continue; >>> >>> I suppose debugfs_transitions[i].devfreq should be set to NULL when >>> devfreq device is removed, but I don't see it happening anywhere in this >>> patch. >> >> When debugfs_transitions[] array is not fully filled out >> by devfreq_update_transitions(), debugfs_transitions[i].devfreq is NULL. >> In this case, if user execute 'cat /sys/kernel/debug/devfreq/devfreq_transitions', >> devfreq_transitions_show() need to check the debugfs_transitions[i].devfreq >> is NULL or not. >> >> After filled out the debugfs_transitions[] array, >> actually, 'if(!devfreq)' is not necessary. Maybe, this style is inefficient >> It need to rework. I'll think again. > > Imagine this situation: > > 1. there is a devfreq device, let's name it defreq123 > > 2. the debugfs_transitions array is getting filled and now it has this > entry: > > debugfs_transitions[0].devfreq = defreq123 > > 3. user removes defreq123 driver module > > # rmmod defreq123 > > 4. the defreq123 is released now > > 5. at what memory location debugfs_transitions[0].devfreq is pointing now? > > You're right. It is my missing point. Instead of storing the devfreq pointer into debugfs_transitions[].devfreq, It is better to copy the necessary information to debugfs_transitions[] for preventing the mentioned situation.
On 1/9/20 12:44 AM, Lukasz Luba wrote: > Hi, > > On 1/8/20 2:20 PM, Dmitry Osipenko wrote: >> 08.01.2020 00:48, Bjorn Andersson пишет: >>> On Tue 07 Jan 01:05 PST 2020, Chanwoo Choi wrote: >>> >>>> Add new devfreq_transitions debugfs file to track the frequency transitions >>>> of all devfreq devices for the simple profiling as following: >>>> - /sys/kernel/debug/devfreq/devfreq_transitions >>>> >>>> And the user can decide the storage size (CONFIG_NR_DEVFREQ_TRANSITIONS) >>>> in Kconfig in order to save the transition history. >>>> >>>> [Detailed description of each field of 'devfreq_transitions' debugfs file] >>>> - time_ms : Change time of frequency transition. (unit: millisecond) >>>> - dev_name : Device name of h/w. >>>> - dev : Device name made by devfreq core. >>>> - parent_dev : If devfreq device uses the passive governor, >>>> show parent devfreq device name. >>>> - load_% : If devfreq device uses the simple_ondemand governor, >>>> load is used by governor whene deciding the new frequency. >>>> (unit: percentage) >>>> - old_freq_hz : Frequency before changing. (unit: hz) >>>> - new_freq_hz : Frequency after changed. (unit: hz) >>>> >>>> [For example on Exynos5422-based Odroid-XU3 board] >>>> $ cat /sys/kernel/debug/devfreq/devfreq_transitions >>>> time_ms dev_name dev parent_dev load_% old_freq_hz new_freq_hz >>>> ---------- ------------------------------ ---------- ---------- ---------- ------------ ------------ >>>> 14600 soc:bus_noc devfreq2 devfreq1 0 100000000 67000000 >>>> 14600 soc:bus_fsys_apb devfreq3 devfreq1 0 200000000 100000000 >>>> 14600 soc:bus_fsys devfreq4 devfreq1 0 200000000 100000000 >>>> 14600 soc:bus_fsys2 devfreq5 devfreq1 0 150000000 75000000 >>>> 14602 soc:bus_mfc devfreq6 devfreq1 0 222000000 96000000 >>>> 14602 soc:bus_gen devfreq7 devfreq1 0 267000000 89000000 >>>> 14602 soc:bus_g2d devfreq9 devfreq1 0 300000000 84000000 >>>> 14602 soc:bus_g2d_acp devfreq10 devfreq1 0 267000000 67000000 >>>> 14602 soc:bus_jpeg devfreq11 devfreq1 0 300000000 75000000 >>>> 14602 soc:bus_jpeg_apb devfreq12 devfreq1 0 167000000 84000000 >>>> 14603 soc:bus_disp1_fimd devfreq13 devfreq1 0 200000000 120000000 >>>> 14603 soc:bus_disp1 devfreq14 devfreq1 0 300000000 120000000 >>>> 14606 soc:bus_gscl_scaler devfreq15 devfreq1 0 300000000 150000000 >>>> 14606 soc:bus_mscl devfreq16 devfreq1 0 333000000 84000000 >>>> 14608 soc:bus_wcore devfreq1 9 333000000 84000000 >>>> 14783 10c20000.memory-controller devfreq0 35 825000000 633000000 >>>> 15873 soc:bus_wcore devfreq1 41 84000000 400000000 >>>> 15873 soc:bus_noc devfreq2 devfreq1 0 67000000 100000000 >>>> [snip] >>>> >>> >>> Wouldn't it make more sense to expose this through the tracing >>> framework - like many other subsystems does? >> >> I think devfreq core already has some tracing support and indeed it >> should be better to extend it rather than duplicate. >> > > In my opinion this debugfs interface should be considered as a helpful > validation entry point. We had some issues with wrong bootloader > configurations in clock tree, where some frequencies could not be set > in the kernel. Similar useful description can be find in clock subsystem > where there is clock tree summary file. > > It is much cheaper to poke a few files in debug dir by some automated > test than starting tracing, provoking desired code flow in the > devfreq for every device, paring the results... A simple boot test > which reads only these new files can be enough to rise the flag. > Secondly the tracing is not always compiled. > > It could capture old/wrong bootloaders which pinned devices > improperly to PLLs or wrong DT values in OPP table. > (a workaround for Odroid xu4 patchset: > https://protect2.fireeye.com/url?k=364d2fbb-6b9993d3-364ca4f4-0cc47a3356b2-98db7e7cf023414c&u=https://lkml.org/lkml/2019/7/15/276 > ) > > Chanwoo what do think about some sanity check summary? > It could be presented in a 3rd file: 'devfreq_sanity', which > could report if the devices could set their registered OPPs > and got the same values, i.e. set 166MHz --> set to 150MHz > in reality. If a config option i.e. DEVFREQ_SANITY is set > then during the registration of a new device it checks OPPs > if they are possible to set. It could be done before assigning > the governor for the device and results present in of of your files. Firstly, I'm welcoming to add new debugging feature. As you suggested, it is required for the OPP control. But, I'm not sure that it have to be verified in either OPP or devfreq. Or it have be verified when adding the OPP table into devicetree file. If we add this debugging feature, I think 'resource_sanity' as following path. /sys/kernel/debug/devfreq/devfreqX/resource_sanity (not fixed name) - show the sanity result of regulator voltage and frequency
On Thu 09 Jan 00:07 PST 2020, Chanwoo Choi wrote: > Hi Bjorn and Dmitry, > > I replied from Bjorn and Dmitry opinion. > > On 1/8/20 11:20 PM, Dmitry Osipenko wrote: > > 08.01.2020 00:48, Bjorn Andersson ??????????: > >> On Tue 07 Jan 01:05 PST 2020, Chanwoo Choi wrote: > >> > >>> Add new devfreq_transitions debugfs file to track the frequency transitions > >>> of all devfreq devices for the simple profiling as following: > >>> - /sys/kernel/debug/devfreq/devfreq_transitions > >>> > >>> And the user can decide the storage size (CONFIG_NR_DEVFREQ_TRANSITIONS) > >>> in Kconfig in order to save the transition history. > >>> > >>> [Detailed description of each field of 'devfreq_transitions' debugfs file] > >>> - time_ms : Change time of frequency transition. (unit: millisecond) > >>> - dev_name : Device name of h/w. > >>> - dev : Device name made by devfreq core. > >>> - parent_dev : If devfreq device uses the passive governor, > >>> show parent devfreq device name. > >>> - load_% : If devfreq device uses the simple_ondemand governor, > >>> load is used by governor whene deciding the new frequency. > >>> (unit: percentage) > >>> - old_freq_hz : Frequency before changing. (unit: hz) > >>> - new_freq_hz : Frequency after changed. (unit: hz) > >>> > >>> [For example on Exynos5422-based Odroid-XU3 board] > >>> $ cat /sys/kernel/debug/devfreq/devfreq_transitions > >>> time_ms dev_name dev parent_dev load_% old_freq_hz new_freq_hz > >>> ---------- ------------------------------ ---------- ---------- ---------- ------------ ------------ > >>> 14600 soc:bus_noc devfreq2 devfreq1 0 100000000 67000000 > >>> 14600 soc:bus_fsys_apb devfreq3 devfreq1 0 200000000 100000000 > >>> 14600 soc:bus_fsys devfreq4 devfreq1 0 200000000 100000000 > >>> 14600 soc:bus_fsys2 devfreq5 devfreq1 0 150000000 75000000 > >>> 14602 soc:bus_mfc devfreq6 devfreq1 0 222000000 96000000 > >>> 14602 soc:bus_gen devfreq7 devfreq1 0 267000000 89000000 > >>> 14602 soc:bus_g2d devfreq9 devfreq1 0 300000000 84000000 > >>> 14602 soc:bus_g2d_acp devfreq10 devfreq1 0 267000000 67000000 > >>> 14602 soc:bus_jpeg devfreq11 devfreq1 0 300000000 75000000 > >>> 14602 soc:bus_jpeg_apb devfreq12 devfreq1 0 167000000 84000000 > >>> 14603 soc:bus_disp1_fimd devfreq13 devfreq1 0 200000000 120000000 > >>> 14603 soc:bus_disp1 devfreq14 devfreq1 0 300000000 120000000 > >>> 14606 soc:bus_gscl_scaler devfreq15 devfreq1 0 300000000 150000000 > >>> 14606 soc:bus_mscl devfreq16 devfreq1 0 333000000 84000000 > >>> 14608 soc:bus_wcore devfreq1 9 333000000 84000000 > >>> 14783 10c20000.memory-controller devfreq0 35 825000000 633000000 > >>> 15873 soc:bus_wcore devfreq1 41 84000000 400000000 > >>> 15873 soc:bus_noc devfreq2 devfreq1 0 67000000 100000000 > >>> [snip] > >>> > >> > >> Wouldn't it make more sense to expose this through the tracing > >> framework - like many other subsystems does? > > > > I think devfreq core already has some tracing support and indeed it > > should be better to extend it rather than duplicate. > > > > First of all, thanks for comments. > > Before developing it, I have considered what is better to > support debugging features for devfreq device. As you commented, > trace event is more general way to catch the detailed behavior. > It's more general, it has already dealt with the locking and life cycle questions that was brought up by others and it allows getting traces devfreq traces in the same timeline as other events (to give insight in cross-framework behavior). > But, I hope to provide the very easy simple profiling way > for user if it is not harmful to the principle of linux kernel. > You would achieve the same simplicity by integrating with the trace framework instead of rolling your own subset of the functionality. I know that it's the principle of the Linux kernel that everyone should have their own ring buffer implementation, but you should try to use the existing ones when it makes sense. And in my view this is a prime example - with many additional benefits of doing so. > In order to prevent the performance regression when DEBUG_FS is enabled, > I will add the CONFIG_DEVFREQ_TRANSITIONS_DEBUG for 'devfreq_transitions' > to make it selectable. > The tracing framework has both static and dynamic mechanisms for avoiding performance penalties when tracing is disabled and does provide better performance than your proposal when active. Relying on a Kconfig option means that with e.g. arm64 devices being built from a single defconfig we will either all be missing this feature or we will all always keep logging devfreq transitions to your buffer. Regards, Bjorn
On 1/10/20 2:21 AM, Bjorn Andersson wrote: > On Thu 09 Jan 00:07 PST 2020, Chanwoo Choi wrote: > >> Hi Bjorn and Dmitry, >> >> I replied from Bjorn and Dmitry opinion. >> >> On 1/8/20 11:20 PM, Dmitry Osipenko wrote: >>> 08.01.2020 00:48, Bjorn Andersson ??????????: >>>> On Tue 07 Jan 01:05 PST 2020, Chanwoo Choi wrote: >>>> >>>>> Add new devfreq_transitions debugfs file to track the frequency transitions >>>>> of all devfreq devices for the simple profiling as following: >>>>> - /sys/kernel/debug/devfreq/devfreq_transitions >>>>> >>>>> And the user can decide the storage size (CONFIG_NR_DEVFREQ_TRANSITIONS) >>>>> in Kconfig in order to save the transition history. >>>>> >>>>> [Detailed description of each field of 'devfreq_transitions' debugfs file] >>>>> - time_ms : Change time of frequency transition. (unit: millisecond) >>>>> - dev_name : Device name of h/w. >>>>> - dev : Device name made by devfreq core. >>>>> - parent_dev : If devfreq device uses the passive governor, >>>>> show parent devfreq device name. >>>>> - load_% : If devfreq device uses the simple_ondemand governor, >>>>> load is used by governor whene deciding the new frequency. >>>>> (unit: percentage) >>>>> - old_freq_hz : Frequency before changing. (unit: hz) >>>>> - new_freq_hz : Frequency after changed. (unit: hz) >>>>> >>>>> [For example on Exynos5422-based Odroid-XU3 board] >>>>> $ cat /sys/kernel/debug/devfreq/devfreq_transitions >>>>> time_ms dev_name dev parent_dev load_% old_freq_hz new_freq_hz >>>>> ---------- ------------------------------ ---------- ---------- ---------- ------------ ------------ >>>>> 14600 soc:bus_noc devfreq2 devfreq1 0 100000000 67000000 >>>>> 14600 soc:bus_fsys_apb devfreq3 devfreq1 0 200000000 100000000 >>>>> 14600 soc:bus_fsys devfreq4 devfreq1 0 200000000 100000000 >>>>> 14600 soc:bus_fsys2 devfreq5 devfreq1 0 150000000 75000000 >>>>> 14602 soc:bus_mfc devfreq6 devfreq1 0 222000000 96000000 >>>>> 14602 soc:bus_gen devfreq7 devfreq1 0 267000000 89000000 >>>>> 14602 soc:bus_g2d devfreq9 devfreq1 0 300000000 84000000 >>>>> 14602 soc:bus_g2d_acp devfreq10 devfreq1 0 267000000 67000000 >>>>> 14602 soc:bus_jpeg devfreq11 devfreq1 0 300000000 75000000 >>>>> 14602 soc:bus_jpeg_apb devfreq12 devfreq1 0 167000000 84000000 >>>>> 14603 soc:bus_disp1_fimd devfreq13 devfreq1 0 200000000 120000000 >>>>> 14603 soc:bus_disp1 devfreq14 devfreq1 0 300000000 120000000 >>>>> 14606 soc:bus_gscl_scaler devfreq15 devfreq1 0 300000000 150000000 >>>>> 14606 soc:bus_mscl devfreq16 devfreq1 0 333000000 84000000 >>>>> 14608 soc:bus_wcore devfreq1 9 333000000 84000000 >>>>> 14783 10c20000.memory-controller devfreq0 35 825000000 633000000 >>>>> 15873 soc:bus_wcore devfreq1 41 84000000 400000000 >>>>> 15873 soc:bus_noc devfreq2 devfreq1 0 67000000 100000000 >>>>> [snip] >>>>> >>>> >>>> Wouldn't it make more sense to expose this through the tracing >>>> framework - like many other subsystems does? >>> >>> I think devfreq core already has some tracing support and indeed it >>> should be better to extend it rather than duplicate. >>> >> >> First of all, thanks for comments. >> >> Before developing it, I have considered what is better to >> support debugging features for devfreq device. As you commented, >> trace event is more general way to catch the detailed behavior. >> > > It's more general, it has already dealt with the locking and life cycle > questions that was brought up by others and it allows getting traces > devfreq traces in the same timeline as other events (to give insight in > cross-framework behavior). > >> But, I hope to provide the very easy simple profiling way >> for user if it is not harmful to the principle of linux kernel. >> > > You would achieve the same simplicity by integrating with the trace > framework instead of rolling your own subset of the functionality. > > I know that it's the principle of the Linux kernel that everyone should > have their own ring buffer implementation, but you should try to use the > existing ones when it makes sense. And in my view this is a prime > example - with many additional benefits of doing so. When we are usually using the profiling tool, existing trace framework is the best. Actually, might need to read the frequency transitions on the user-space process which is related to monitoring, without the enabled trace configuration. > >> In order to prevent the performance regression when DEBUG_FS is enabled, >> I will add the CONFIG_DEVFREQ_TRANSITIONS_DEBUG for 'devfreq_transitions' >> to make it selectable. >> > > The tracing framework has both static and dynamic mechanisms for > avoiding performance penalties when tracing is disabled and does provide > better performance than your proposal when active. It provides the separate configuration to select them by user. It is optional. It means that if CONFIG_DEVFREQ_TRANSITIONS_DEBUG is enabled by user, the user has made a choice this situation with even if the some regression happen and instead get the frequency transition for monitoring on user-space process. > > Relying on a Kconfig option means that with e.g. arm64 devices being > built from a single defconfig we will either all be missing this feature > or we will all always keep logging devfreq transitions to your buffer. The single defconfig doesn't contain the all configuration provided from linux kernel. Furthermore, the debug option is optional by user. I think that it doesn't matter.
Hi Bjorn, On 1/10/20 2:04 PM, Chanwoo Choi wrote: > On 1/10/20 2:21 AM, Bjorn Andersson wrote: >> On Thu 09 Jan 00:07 PST 2020, Chanwoo Choi wrote: >> >>> Hi Bjorn and Dmitry, >>> >>> I replied from Bjorn and Dmitry opinion. >>> >>> On 1/8/20 11:20 PM, Dmitry Osipenko wrote: >>>> 08.01.2020 00:48, Bjorn Andersson ??????????: >>>>> On Tue 07 Jan 01:05 PST 2020, Chanwoo Choi wrote: >>>>> >>>>>> Add new devfreq_transitions debugfs file to track the frequency transitions >>>>>> of all devfreq devices for the simple profiling as following: >>>>>> - /sys/kernel/debug/devfreq/devfreq_transitions >>>>>> >>>>>> And the user can decide the storage size (CONFIG_NR_DEVFREQ_TRANSITIONS) >>>>>> in Kconfig in order to save the transition history. >>>>>> >>>>>> [Detailed description of each field of 'devfreq_transitions' debugfs file] >>>>>> - time_ms : Change time of frequency transition. (unit: millisecond) >>>>>> - dev_name : Device name of h/w. >>>>>> - dev : Device name made by devfreq core. >>>>>> - parent_dev : If devfreq device uses the passive governor, >>>>>> show parent devfreq device name. >>>>>> - load_% : If devfreq device uses the simple_ondemand governor, >>>>>> load is used by governor whene deciding the new frequency. >>>>>> (unit: percentage) >>>>>> - old_freq_hz : Frequency before changing. (unit: hz) >>>>>> - new_freq_hz : Frequency after changed. (unit: hz) >>>>>> >>>>>> [For example on Exynos5422-based Odroid-XU3 board] >>>>>> $ cat /sys/kernel/debug/devfreq/devfreq_transitions >>>>>> time_ms dev_name dev parent_dev load_% old_freq_hz new_freq_hz >>>>>> ---------- ------------------------------ ---------- ---------- ---------- ------------ ------------ >>>>>> 14600 soc:bus_noc devfreq2 devfreq1 0 100000000 67000000 >>>>>> 14600 soc:bus_fsys_apb devfreq3 devfreq1 0 200000000 100000000 >>>>>> 14600 soc:bus_fsys devfreq4 devfreq1 0 200000000 100000000 >>>>>> 14600 soc:bus_fsys2 devfreq5 devfreq1 0 150000000 75000000 >>>>>> 14602 soc:bus_mfc devfreq6 devfreq1 0 222000000 96000000 >>>>>> 14602 soc:bus_gen devfreq7 devfreq1 0 267000000 89000000 >>>>>> 14602 soc:bus_g2d devfreq9 devfreq1 0 300000000 84000000 >>>>>> 14602 soc:bus_g2d_acp devfreq10 devfreq1 0 267000000 67000000 >>>>>> 14602 soc:bus_jpeg devfreq11 devfreq1 0 300000000 75000000 >>>>>> 14602 soc:bus_jpeg_apb devfreq12 devfreq1 0 167000000 84000000 >>>>>> 14603 soc:bus_disp1_fimd devfreq13 devfreq1 0 200000000 120000000 >>>>>> 14603 soc:bus_disp1 devfreq14 devfreq1 0 300000000 120000000 >>>>>> 14606 soc:bus_gscl_scaler devfreq15 devfreq1 0 300000000 150000000 >>>>>> 14606 soc:bus_mscl devfreq16 devfreq1 0 333000000 84000000 >>>>>> 14608 soc:bus_wcore devfreq1 9 333000000 84000000 >>>>>> 14783 10c20000.memory-controller devfreq0 35 825000000 633000000 >>>>>> 15873 soc:bus_wcore devfreq1 41 84000000 400000000 >>>>>> 15873 soc:bus_noc devfreq2 devfreq1 0 67000000 100000000 >>>>>> [snip] >>>>>> >>>>> >>>>> Wouldn't it make more sense to expose this through the tracing >>>>> framework - like many other subsystems does? >>>> >>>> I think devfreq core already has some tracing support and indeed it >>>> should be better to extend it rather than duplicate. >>>> >>> >>> First of all, thanks for comments. >>> >>> Before developing it, I have considered what is better to >>> support debugging features for devfreq device. As you commented, >>> trace event is more general way to catch the detailed behavior. >>> >> >> It's more general, it has already dealt with the locking and life cycle >> questions that was brought up by others and it allows getting traces >> devfreq traces in the same timeline as other events (to give insight in >> cross-framework behavior). >> >>> But, I hope to provide the very easy simple profiling way >>> for user if it is not harmful to the principle of linux kernel. >>> >> >> You would achieve the same simplicity by integrating with the trace >> framework instead of rolling your own subset of the functionality. >> >> I know that it's the principle of the Linux kernel that everyone should >> have their own ring buffer implementation, but you should try to use the >> existing ones when it makes sense. And in my view this is a prime >> example - with many additional benefits of doing so. > > When we are usually using the profiling tool, existing trace framework > is the best. Actually, might need to read the frequency transitions > on the user-space process which is related to monitoring, without > the enabled trace configuration. > >> >>> In order to prevent the performance regression when DEBUG_FS is enabled, >>> I will add the CONFIG_DEVFREQ_TRANSITIONS_DEBUG for 'devfreq_transitions' >>> to make it selectable. >>> >> >> The tracing framework has both static and dynamic mechanisms for >> avoiding performance penalties when tracing is disabled and does provide >> better performance than your proposal when active. > > It provides the separate configuration to select them by user. > It is optional. It means that if CONFIG_DEVFREQ_TRANSITIONS_DEBUG > is enabled by user, the user has made a choice this situation with > even if the some regression happen and instead get the frequency > transition for monitoring on user-space process. > >> >> Relying on a Kconfig option means that with e.g. arm64 devices being >> built from a single defconfig we will either all be missing this feature >> or we will all always keep logging devfreq transitions to your buffer. > > The single defconfig doesn't contain the all configuration provided > from linux kernel. Furthermore, the debug option is optional by user. > I think that it doesn't matter. > Basically, I agree that trace point is better. Just as I said, I hope to provide the very easy simple profiling way. But, as you suggested and I knew that it seems that duplicate feature. So, I'll drop it and extend the existing trace point of devfreq. Thanks for your comment and discussion.
Hi Chanwoo, On 07.01.2020 10:05, Chanwoo Choi wrote: > Add new devfreq_transitions debugfs file to track the frequency transitions > of all devfreq devices for the simple profiling as following: > - /sys/kernel/debug/devfreq/devfreq_transitions > > And the user can decide the storage size (CONFIG_NR_DEVFREQ_TRANSITIONS) > in Kconfig in order to save the transition history. > > [Detailed description of each field of 'devfreq_transitions' debugfs file] > - time_ms : Change time of frequency transition. (unit: millisecond) > - dev_name : Device name of h/w. > - dev : Device name made by devfreq core. > - parent_dev : If devfreq device uses the passive governor, > show parent devfreq device name. > - load_% : If devfreq device uses the simple_ondemand governor, > load is used by governor whene deciding the new frequency. > (unit: percentage) > - old_freq_hz : Frequency before changing. (unit: hz) s/hz/Hz/ > - new_freq_hz : Frequency after changed. (unit: hz) s/hz/Hz/ > > [For example on Exynos5422-based Odroid-XU3 board] > $ cat /sys/kernel/debug/devfreq/devfreq_transitions > time_ms dev_name dev parent_dev load_% old_freq_hz new_freq_hz s/hz/Hz/ > ---------- ------------------------------ ---------- ---------- ---------- ------------ ------------ > 14600 soc:bus_noc devfreq2 devfreq1 0 100000000 67000000 > 14600 soc:bus_fsys_apb devfreq3 devfreq1 0 200000000 100000000 Imho it is better to align freq numbers to right, for example: 14600 soc:bus_noc devfreq2 devfreq1 0 100000000 67000000 14600 soc:bus_fsys_apb devfreq3 devfreq1 0 200000000 100000000 > 14600 soc:bus_fsys devfreq4 devfreq1 0 200000000 100000000 > 14600 soc:bus_fsys2 devfreq5 devfreq1 0 150000000 75000000 > 14602 soc:bus_mfc devfreq6 devfreq1 0 222000000 96000000 > 14602 soc:bus_gen devfreq7 devfreq1 0 267000000 89000000 > 14602 soc:bus_g2d devfreq9 devfreq1 0 300000000 84000000 > 14602 soc:bus_g2d_acp devfreq10 devfreq1 0 267000000 67000000 > 14602 soc:bus_jpeg devfreq11 devfreq1 0 300000000 75000000 > 14602 soc:bus_jpeg_apb devfreq12 devfreq1 0 167000000 84000000 > 14603 soc:bus_disp1_fimd devfreq13 devfreq1 0 200000000 120000000 > 14603 soc:bus_disp1 devfreq14 devfreq1 0 300000000 120000000 > 14606 soc:bus_gscl_scaler devfreq15 devfreq1 0 300000000 150000000 > 14606 soc:bus_mscl devfreq16 devfreq1 0 333000000 84000000 > 14608 soc:bus_wcore devfreq1 9 333000000 84000000 > 14783 10c20000.memory-controller devfreq0 35 825000000 633000000 > 15873 soc:bus_wcore devfreq1 41 84000000 400000000 > 15873 soc:bus_noc devfreq2 devfreq1 0 67000000 100000000 > [snip] > > Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> > --- > drivers/devfreq/Kconfig | 13 +++ > drivers/devfreq/devfreq.c | 126 +++++++++++++++++++++++++++++ > drivers/devfreq/governor.h | 3 + > drivers/devfreq/governor_passive.c | 2 + > include/linux/devfreq.h | 1 + > 5 files changed, 145 insertions(+) > > diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig > index 0b1df12e0f21..84936eec0ef9 100644 > --- a/drivers/devfreq/Kconfig > +++ b/drivers/devfreq/Kconfig > @@ -74,6 +74,19 @@ config DEVFREQ_GOV_PASSIVE > through sysfs entries. The passive governor recommends that > devfreq device uses the OPP table to get the frequency/voltage. > > +comment "DEVFREQ Debugging" > + > +config NR_DEVFREQ_TRANSITIONS > + int "Maximum storage size to save DEVFREQ Transitions (10-1000)" > + depends on DEBUG_FS > + range 10 1000 > + default "100" > + help > + Show the frequency transitions of all devfreq devices via > + '/sys/kernel/debug/devfreq/devfreq_transitions' for the simple > + profiling. It needs to decide the storage size to save transition > + history of all devfreq devices. > + > comment "DEVFREQ Drivers" > > config ARM_EXYNOS_BUS_DEVFREQ > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c > index c7f5e4e06420..7abaae06fa65 100644 > --- a/drivers/devfreq/devfreq.c > +++ b/drivers/devfreq/devfreq.c > @@ -268,6 +268,57 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq) > } > EXPORT_SYMBOL(devfreq_update_status); > > +/** > + * devfreq_update_transitions() - Update frequency transitions for debugfs file > + * @devfreq: the devfreq instance > + * @old_freq: the previous frequency before changing the frequency > + * @new_freq: the new frequency after frequency is changed > + */ > +struct devfreq_transitions { > + struct devfreq *devfreq; > + struct devfreq_freqs freqs; > + unsigned long load; > +} debugfs_transitions[CONFIG_NR_DEVFREQ_TRANSITIONS]; > + > +static spinlock_t devfreq_debugfs_lock; > +static int debugfs_transitions_index; > + > +void devfreq_update_transitions(struct devfreq *devfreq, > + unsigned long old_freq, unsigned long new_freq, > + unsigned long busy_time, unsigned long total_time) > +{ > + unsigned long load; > + int i; > + > + if (!devfreq_debugfs || !devfreq || (old_freq == new_freq)) > + return; > + > + spin_lock_nested(&devfreq_debugfs_lock, SINGLE_DEPTH_NESTING); > + > + i = debugfs_transitions_index; > + > + /* > + * Calculate the load and if load is larger than 100, > + * initialize to 100 because the unit of load is percentage. > + */ Remove this comment, it is better to print numbers as they are so one can find a problem. > + load = (total_time == 0 ? 0 : (100 * busy_time) / total_time); > + if (load > 100) > + load = 100; Imho it should always be busy_time <= total_time, so if (load > 100) { WARN_ONCE(busy_time > total_time, "devfreq: busy_time > total_time"); load = 100; } Or drop this "if (load > 100) load=100;" and print load as is in logs. > + > + debugfs_transitions[i].devfreq = devfreq; > + debugfs_transitions[i].freqs.time = ktime_to_ms(ktime_get()); > + debugfs_transitions[i].freqs.old = old_freq; > + debugfs_transitions[i].freqs.new = new_freq; > + debugfs_transitions[i].load = load; > + > + if (++i == CONFIG_NR_DEVFREQ_TRANSITIONS) > + i = 0; > + debugfs_transitions_index = i; > + > + spin_unlock(&devfreq_debugfs_lock); > +} > +EXPORT_SYMBOL(devfreq_update_transitions); > + > /** > * find_devfreq_governor() - Find devfreq governor from name > * @name: name of the governor > @@ -401,6 +452,10 @@ static int set_target(struct devfreq *devfreq, > return err; > } > > + devfreq_update_transitions(devfreq, cur_freq, new_freq, > + devfreq->last_status.busy_time, > + devfreq->last_status.total_time); > + > freqs.new = new_freq; > notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE); > > @@ -1787,6 +1842,72 @@ static int devfreq_summary_show(struct seq_file *s, void *data) > } > DEFINE_SHOW_ATTRIBUTE(devfreq_summary); > > +/** > + * devfreq_transitions_show() - Show the frequency transitions of the registered > + * devfreq devices via 'devfreq_transitions' debugfs file. > + */ > +static int devfreq_transitions_show(struct seq_file *s, void *data) > +{ > + struct devfreq *devfreq = NULL; > + struct devfreq *p_devfreq = NULL; > + struct devfreq_freqs *freqs = NULL; > + unsigned long load; > + int i = debugfs_transitions_index; > + int count; > + > + seq_printf(s, "%-10s %-30s %-10s %-10s %-6s %-12s %-12s\n", > + "time_ms", > + "dev_name", > + "dev", > + "parent_dev", > + "load_%", > + "old_freq_hz", > + "new_freq_hz"); > + seq_printf(s, "%-10s %-30s %-10s %-10s %-6s %-12s %-12s\n", > + "----------", > + "------------------------------", > + "----------", > + "----------", > + "----------", > + "------------", > + "------------"); > + > + spin_lock(&devfreq_debugfs_lock); > + for (count = 0; count < CONFIG_NR_DEVFREQ_TRANSITIONS; count++) { > + devfreq = debugfs_transitions[i].devfreq; > + freqs = &debugfs_transitions[i].freqs; > + load = debugfs_transitions[i].load; > + > + i = (CONFIG_NR_DEVFREQ_TRANSITIONS == ++i) ? 0 : i; > + if (!devfreq) > + continue; > + > +#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE) > + if (!strncmp(devfreq->governor_name, > + DEVFREQ_GOV_PASSIVE, DEVFREQ_NAME_LEN)) { > + struct devfreq_passive_data *data = devfreq->data; > + > + if (data) > + p_devfreq = data->parent; > + } else { > + p_devfreq = NULL; > + } > +#endif > + seq_printf(s, "%-10lld %-30s %-10s %-10s %-6ld %-12ld %-12ld\n", > + freqs->time, > + dev_name(devfreq->dev.parent), > + dev_name(&devfreq->dev), > + p_devfreq ? dev_name(&p_devfreq->dev) : "", > + load, > + freqs->old, > + freqs->new); > + } > + spin_unlock(&devfreq_debugfs_lock); > + > + return 0; > +} > +DEFINE_SHOW_ATTRIBUTE(devfreq_transitions); > + > static int __init devfreq_init(void) > { > devfreq_class = class_create(THIS_MODULE, "devfreq"); > @@ -1808,9 +1929,14 @@ static int __init devfreq_init(void) > devfreq_debugfs = NULL; > pr_warn("%s: couldn't create debugfs dir\n", __FILE__); > } else { > + spin_lock_init(&devfreq_debugfs_lock); > + > debugfs_create_file("devfreq_summary", 0444, > devfreq_debugfs, NULL, > &devfreq_summary_fops); > + debugfs_create_file("devfreq_transitions", 0444, > + devfreq_debugfs, NULL, > + &devfreq_transitions_fops); > } > > return 0; > diff --git a/drivers/devfreq/governor.h b/drivers/devfreq/governor.h > index dc7533ccc3db..01eecfdaf2d6 100644 > --- a/drivers/devfreq/governor.h > +++ b/drivers/devfreq/governor.h > @@ -68,6 +68,9 @@ extern int devfreq_add_governor(struct devfreq_governor *governor); > extern int devfreq_remove_governor(struct devfreq_governor *governor); > > extern int devfreq_update_status(struct devfreq *devfreq, unsigned long freq); > +extern void devfreq_update_transitions(struct devfreq *devfreq, > + unsigned long old_freq, unsigned long new_freq, > + unsigned long busy_time, unsigned long total_time); > > static inline int devfreq_update_stats(struct devfreq *df) > { > diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c > index be6eeab9c814..05fa654239f5 100644 > --- a/drivers/devfreq/governor_passive.c > +++ b/drivers/devfreq/governor_passive.c > @@ -109,6 +109,8 @@ static int update_devfreq_passive(struct devfreq *devfreq, unsigned long freq) > if (ret < 0) > goto out; > > + devfreq_update_transitions(devfreq, devfreq->previous_freq, freq, 0, 0); > + > if (devfreq->profile->freq_table > && (devfreq_update_status(devfreq, freq))) > dev_err(&devfreq->dev, > diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h > index 49cdb2378030..933692e5d867 100644 > --- a/include/linux/devfreq.h > +++ b/include/linux/devfreq.h > @@ -196,6 +196,7 @@ struct devfreq { > }; > > struct devfreq_freqs { > + s64 time; Imho is should be moved to struct devfreq_transitions. Or do you plan to change load calculations based on time ? > unsigned long old; > unsigned long new; > }; >
On 08.01.2020 17:44, Lukasz Luba wrote: > On 1/8/20 2:20 PM, Dmitry Osipenko wrote: >> 08.01.2020 00:48, Bjorn Andersson пишет: >>> On Tue 07 Jan 01:05 PST 2020, Chanwoo Choi wrote: >>> >>>> Add new devfreq_transitions debugfs file to track the frequency transitions >>>> of all devfreq devices for the simple profiling as following: >>>> - /sys/kernel/debug/devfreq/devfreq_transitions >>>> >>>> And the user can decide the storage size (CONFIG_NR_DEVFREQ_TRANSITIONS) >>>> in Kconfig in order to save the transition history. >>>> >>>> [Detailed description of each field of 'devfreq_transitions' debugfs file] >>>> - time_ms : Change time of frequency transition. (unit: millisecond) >>>> - dev_name : Device name of h/w. >>>> - dev : Device name made by devfreq core. >>>> - parent_dev : If devfreq device uses the passive governor, >>>> show parent devfreq device name. >>>> - load_% : If devfreq device uses the simple_ondemand governor, >>>> load is used by governor whene deciding the new frequency. >>>> (unit: percentage) >>>> - old_freq_hz : Frequency before changing. (unit: hz) >>>> - new_freq_hz : Frequency after changed. (unit: hz) >>>> >>>> [For example on Exynos5422-based Odroid-XU3 board] >>>> $ cat /sys/kernel/debug/devfreq/devfreq_transitions >>>> time_ms dev_name dev parent_dev load_% old_freq_hz new_freq_hz >>>> ---------- ------------------------------ ---------- ---------- ---------- ------------ ------------ >>>> 14600 soc:bus_noc devfreq2 devfreq1 0 100000000 67000000 >>>> 14600 soc:bus_fsys_apb devfreq3 devfreq1 0 200000000 100000000 >>>> 14600 soc:bus_fsys devfreq4 devfreq1 0 200000000 100000000 >>>> 14600 soc:bus_fsys2 devfreq5 devfreq1 0 150000000 75000000 >>>> 14602 soc:bus_mfc devfreq6 devfreq1 0 222000000 96000000 >>>> 14602 soc:bus_gen devfreq7 devfreq1 0 267000000 89000000 >>>> 14602 soc:bus_g2d devfreq9 devfreq1 0 300000000 84000000 >>>> 14602 soc:bus_g2d_acp devfreq10 devfreq1 0 267000000 67000000 >>>> 14602 soc:bus_jpeg devfreq11 devfreq1 0 300000000 75000000 >>>> 14602 soc:bus_jpeg_apb devfreq12 devfreq1 0 167000000 84000000 >>>> 14603 soc:bus_disp1_fimd devfreq13 devfreq1 0 200000000 120000000 >>>> 14603 soc:bus_disp1 devfreq14 devfreq1 0 300000000 120000000 >>>> 14606 soc:bus_gscl_scaler devfreq15 devfreq1 0 300000000 150000000 >>>> 14606 soc:bus_mscl devfreq16 devfreq1 0 333000000 84000000 >>>> 14608 soc:bus_wcore devfreq1 9 333000000 84000000 >>>> 14783 10c20000.memory-controller devfreq0 35 825000000 633000000 >>>> 15873 soc:bus_wcore devfreq1 41 84000000 400000000 >>>> 15873 soc:bus_noc devfreq2 devfreq1 0 67000000 100000000 >>>> [snip] >>>> >>> >>> Wouldn't it make more sense to expose this through the tracing >>> framework - like many other subsystems does? >> >> I think devfreq core already has some tracing support and indeed it >> should be better to extend it rather than duplicate. +1 for tracing > In my opinion this debugfs interface should be considered as a helpful > validation entry point. We had some issues with wrong bootloader > configurations in clock tree, where some frequencies could not be set > in the kernel. Similar useful description can be find in clock subsystem > where there is clock tree summary file. > > It is much cheaper to poke a few files in debug dir by some automated > test than starting tracing, provoking desired code flow in the > devfreq for every device, paring the results... A simple boot test > which reads only these new files can be enough to rise the flag. Tracepoints are also very powerful for debugging boot issues! You can add "tp_printk trace_event=devfreq:*" to boot arguments and you will see console messages for all relevant events. This works even if boot fails before userspace is available to mount debugfs. > Secondly the tracing is not always compiled. Tracing is deliberately light-weight and should be enabled even on production systems. > It could capture old/wrong bootloaders which pinned devices > improperly to PLLs or wrong DT values in OPP table. > (a workaround for Odroid xu4 patchset: > https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flkml.org%2Flkml%2F2019%2F7%2F15%2F276&data=02%7C01%7Cleonard.crestez%40nxp.com%7C8397d37b41474137f8cf08d79451a007%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637140950611913278&sdata=rcbWCyFmf0ZO7LU27D05mftTf8YdSvGPYNsst1GnNjQ%3D&reserved=0 > ) > > Chanwoo what do think about some sanity check summary? > It could be presented in a 3rd file: 'devfreq_sanity', which > could report if the devices could set their registered OPPs > and got the same values, i.e. set 166MHz --> set to 150MHz > in reality. If a config option i.e. DEVFREQ_SANITY is set > then during the registration of a new device it checks OPPs > if they are possible to set. It could be done before assigning > the governor for the device and results present in of of your files. The new devfreq_transition tracepoint could include a field for "new_effective freq" next to "old_freq" and "new_requested_freq". For imx8m-ddrc I handled this inside the target() function: clk_get_rate is called after the transition and an error is reported if rate doesn't match. It might make sense for devfreq core to handle this internally by calling get_cur_freq instead. -- Regards, Leonard
Hi Leonard, On 1/13/20 5:19 PM, Leonard Crestez wrote: > On 08.01.2020 17:44, Lukasz Luba wrote: >> On 1/8/20 2:20 PM, Dmitry Osipenko wrote: >>> 08.01.2020 00:48, Bjorn Andersson пишет: >>>> On Tue 07 Jan 01:05 PST 2020, Chanwoo Choi wrote: >>>> >>>>> Add new devfreq_transitions debugfs file to track the frequency transitions >>>>> of all devfreq devices for the simple profiling as following: >>>>> - /sys/kernel/debug/devfreq/devfreq_transitions >>>>> >>>>> And the user can decide the storage size (CONFIG_NR_DEVFREQ_TRANSITIONS) >>>>> in Kconfig in order to save the transition history. >>>>> >>>>> [Detailed description of each field of 'devfreq_transitions' debugfs file] >>>>> - time_ms : Change time of frequency transition. (unit: millisecond) >>>>> - dev_name : Device name of h/w. >>>>> - dev : Device name made by devfreq core. >>>>> - parent_dev : If devfreq device uses the passive governor, >>>>> show parent devfreq device name. >>>>> - load_% : If devfreq device uses the simple_ondemand governor, >>>>> load is used by governor whene deciding the new frequency. >>>>> (unit: percentage) >>>>> - old_freq_hz : Frequency before changing. (unit: hz) >>>>> - new_freq_hz : Frequency after changed. (unit: hz) >>>>> >>>>> [For example on Exynos5422-based Odroid-XU3 board] >>>>> $ cat /sys/kernel/debug/devfreq/devfreq_transitions >>>>> time_ms dev_name dev parent_dev load_% old_freq_hz new_freq_hz >>>>> ---------- ------------------------------ ---------- ---------- ---------- ------------ ------------ >>>>> 14600 soc:bus_noc devfreq2 devfreq1 0 100000000 67000000 >>>>> 14600 soc:bus_fsys_apb devfreq3 devfreq1 0 200000000 100000000 >>>>> 14600 soc:bus_fsys devfreq4 devfreq1 0 200000000 100000000 >>>>> 14600 soc:bus_fsys2 devfreq5 devfreq1 0 150000000 75000000 >>>>> 14602 soc:bus_mfc devfreq6 devfreq1 0 222000000 96000000 >>>>> 14602 soc:bus_gen devfreq7 devfreq1 0 267000000 89000000 >>>>> 14602 soc:bus_g2d devfreq9 devfreq1 0 300000000 84000000 >>>>> 14602 soc:bus_g2d_acp devfreq10 devfreq1 0 267000000 67000000 >>>>> 14602 soc:bus_jpeg devfreq11 devfreq1 0 300000000 75000000 >>>>> 14602 soc:bus_jpeg_apb devfreq12 devfreq1 0 167000000 84000000 >>>>> 14603 soc:bus_disp1_fimd devfreq13 devfreq1 0 200000000 120000000 >>>>> 14603 soc:bus_disp1 devfreq14 devfreq1 0 300000000 120000000 >>>>> 14606 soc:bus_gscl_scaler devfreq15 devfreq1 0 300000000 150000000 >>>>> 14606 soc:bus_mscl devfreq16 devfreq1 0 333000000 84000000 >>>>> 14608 soc:bus_wcore devfreq1 9 333000000 84000000 >>>>> 14783 10c20000.memory-controller devfreq0 35 825000000 633000000 >>>>> 15873 soc:bus_wcore devfreq1 41 84000000 400000000 >>>>> 15873 soc:bus_noc devfreq2 devfreq1 0 67000000 100000000 >>>>> [snip] >>>>> >>>> >>>> Wouldn't it make more sense to expose this through the tracing >>>> framework - like many other subsystems does? >>> >>> I think devfreq core already has some tracing support and indeed it >>> should be better to extend it rather than duplicate. > > +1 for tracing >> In my opinion this debugfs interface should be considered as a helpful >> validation entry point. We had some issues with wrong bootloader >> configurations in clock tree, where some frequencies could not be set >> in the kernel. Similar useful description can be find in clock subsystem >> where there is clock tree summary file. >> >> It is much cheaper to poke a few files in debug dir by some automated >> test than starting tracing, provoking desired code flow in the >> devfreq for every device, paring the results... A simple boot test >> which reads only these new files can be enough to rise the flag. > > Tracepoints are also very powerful for debugging boot issues! You can > add "tp_printk trace_event=devfreq:*" to boot arguments and you will see > console messages for all relevant events. This works even if boot fails > before userspace is available to mount debugfs. > >> Secondly the tracing is not always compiled. > > Tracing is deliberately light-weight and should be enabled even on > production systems. > >> It could capture old/wrong bootloaders which pinned devices >> improperly to PLLs or wrong DT values in OPP table. >> (a workaround for Odroid xu4 patchset: >> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flkml.org%2Flkml%2F2019%2F7%2F15%2F276&data=02%7C01%7Cleonard.crestez%40nxp.com%7C8397d37b41474137f8cf08d79451a007%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637140950611913278&sdata=rcbWCyFmf0ZO7LU27D05mftTf8YdSvGPYNsst1GnNjQ%3D&reserved=0 >> ) >> >> Chanwoo what do think about some sanity check summary? >> It could be presented in a 3rd file: 'devfreq_sanity', which >> could report if the devices could set their registered OPPs >> and got the same values, i.e. set 166MHz --> set to 150MHz >> in reality. If a config option i.e. DEVFREQ_SANITY is set >> then during the registration of a new device it checks OPPs >> if they are possible to set. It could be done before assigning >> the governor for the device and results present in of of your files. > > The new devfreq_transition tracepoint could include a field for > "new_effective freq" next to "old_freq" and "new_requested_freq". I would suggest to keep it aligned with cpufreq trace. The timestamps in trace would tell you the history, 'old_freq' is not needed. The trace_devfreq_monitor that I have added should give you this information when you parse all the events. > > For imx8m-ddrc I handled this inside the target() function: clk_get_rate > is called after the transition and an error is reported if rate doesn't > match. Interesting driver, it uses ARM SMCCC like rk3399. It handles this validation of DT OPPs vs firmware OPPs and disables not matched frequencies. Small nit. The error is printed when the 'ret' is 0 and freq does not match, but then 'ret' is returned from target(). You don't also revert the update parent stuff in such case. Maybe you can also check the res.a0 != SMCCC_RET_SUCCESS in static void imx8m_ddrc_smc_set_freq(int target_freq) to bail out earlier and not switch to new parents when the freq switch failed or does not match. Or I am missing something. You can also reorder the includes alphabetically. Regards, Lukasz > > It might make sense for devfreq core to handle this internally by > calling get_cur_freq instead. > > -- > Regards, > Leonard >
diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig index 0b1df12e0f21..84936eec0ef9 100644 --- a/drivers/devfreq/Kconfig +++ b/drivers/devfreq/Kconfig @@ -74,6 +74,19 @@ config DEVFREQ_GOV_PASSIVE through sysfs entries. The passive governor recommends that devfreq device uses the OPP table to get the frequency/voltage. +comment "DEVFREQ Debugging" + +config NR_DEVFREQ_TRANSITIONS + int "Maximum storage size to save DEVFREQ Transitions (10-1000)" + depends on DEBUG_FS + range 10 1000 + default "100" + help + Show the frequency transitions of all devfreq devices via + '/sys/kernel/debug/devfreq/devfreq_transitions' for the simple + profiling. It needs to decide the storage size to save transition + history of all devfreq devices. + comment "DEVFREQ Drivers" config ARM_EXYNOS_BUS_DEVFREQ diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index c7f5e4e06420..7abaae06fa65 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -268,6 +268,57 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq) } EXPORT_SYMBOL(devfreq_update_status); +/** + * devfreq_update_transitions() - Update frequency transitions for debugfs file + * @devfreq: the devfreq instance + * @old_freq: the previous frequency before changing the frequency + * @new_freq: the new frequency after frequency is changed + */ +struct devfreq_transitions { + struct devfreq *devfreq; + struct devfreq_freqs freqs; + unsigned long load; +} debugfs_transitions[CONFIG_NR_DEVFREQ_TRANSITIONS]; + +static spinlock_t devfreq_debugfs_lock; +static int debugfs_transitions_index; + +void devfreq_update_transitions(struct devfreq *devfreq, + unsigned long old_freq, unsigned long new_freq, + unsigned long busy_time, unsigned long total_time) +{ + unsigned long load; + int i; + + if (!devfreq_debugfs || !devfreq || (old_freq == new_freq)) + return; + + spin_lock_nested(&devfreq_debugfs_lock, SINGLE_DEPTH_NESTING); + + i = debugfs_transitions_index; + + /* + * Calculate the load and if load is larger than 100, + * initialize to 100 because the unit of load is percentage. + */ + load = (total_time == 0 ? 0 : (100 * busy_time) / total_time); + if (load > 100) + load = 100; + + debugfs_transitions[i].devfreq = devfreq; + debugfs_transitions[i].freqs.time = ktime_to_ms(ktime_get()); + debugfs_transitions[i].freqs.old = old_freq; + debugfs_transitions[i].freqs.new = new_freq; + debugfs_transitions[i].load = load; + + if (++i == CONFIG_NR_DEVFREQ_TRANSITIONS) + i = 0; + debugfs_transitions_index = i; + + spin_unlock(&devfreq_debugfs_lock); +} +EXPORT_SYMBOL(devfreq_update_transitions); + /** * find_devfreq_governor() - Find devfreq governor from name * @name: name of the governor @@ -401,6 +452,10 @@ static int set_target(struct devfreq *devfreq, return err; } + devfreq_update_transitions(devfreq, cur_freq, new_freq, + devfreq->last_status.busy_time, + devfreq->last_status.total_time); + freqs.new = new_freq; notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE); @@ -1787,6 +1842,72 @@ static int devfreq_summary_show(struct seq_file *s, void *data) } DEFINE_SHOW_ATTRIBUTE(devfreq_summary); +/** + * devfreq_transitions_show() - Show the frequency transitions of the registered + * devfreq devices via 'devfreq_transitions' debugfs file. + */ +static int devfreq_transitions_show(struct seq_file *s, void *data) +{ + struct devfreq *devfreq = NULL; + struct devfreq *p_devfreq = NULL; + struct devfreq_freqs *freqs = NULL; + unsigned long load; + int i = debugfs_transitions_index; + int count; + + seq_printf(s, "%-10s %-30s %-10s %-10s %-6s %-12s %-12s\n", + "time_ms", + "dev_name", + "dev", + "parent_dev", + "load_%", + "old_freq_hz", + "new_freq_hz"); + seq_printf(s, "%-10s %-30s %-10s %-10s %-6s %-12s %-12s\n", + "----------", + "------------------------------", + "----------", + "----------", + "----------", + "------------", + "------------"); + + spin_lock(&devfreq_debugfs_lock); + for (count = 0; count < CONFIG_NR_DEVFREQ_TRANSITIONS; count++) { + devfreq = debugfs_transitions[i].devfreq; + freqs = &debugfs_transitions[i].freqs; + load = debugfs_transitions[i].load; + + i = (CONFIG_NR_DEVFREQ_TRANSITIONS == ++i) ? 0 : i; + if (!devfreq) + continue; + +#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE) + if (!strncmp(devfreq->governor_name, + DEVFREQ_GOV_PASSIVE, DEVFREQ_NAME_LEN)) { + struct devfreq_passive_data *data = devfreq->data; + + if (data) + p_devfreq = data->parent; + } else { + p_devfreq = NULL; + } +#endif + seq_printf(s, "%-10lld %-30s %-10s %-10s %-6ld %-12ld %-12ld\n", + freqs->time, + dev_name(devfreq->dev.parent), + dev_name(&devfreq->dev), + p_devfreq ? dev_name(&p_devfreq->dev) : "", + load, + freqs->old, + freqs->new); + } + spin_unlock(&devfreq_debugfs_lock); + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(devfreq_transitions); + static int __init devfreq_init(void) { devfreq_class = class_create(THIS_MODULE, "devfreq"); @@ -1808,9 +1929,14 @@ static int __init devfreq_init(void) devfreq_debugfs = NULL; pr_warn("%s: couldn't create debugfs dir\n", __FILE__); } else { + spin_lock_init(&devfreq_debugfs_lock); + debugfs_create_file("devfreq_summary", 0444, devfreq_debugfs, NULL, &devfreq_summary_fops); + debugfs_create_file("devfreq_transitions", 0444, + devfreq_debugfs, NULL, + &devfreq_transitions_fops); } return 0; diff --git a/drivers/devfreq/governor.h b/drivers/devfreq/governor.h index dc7533ccc3db..01eecfdaf2d6 100644 --- a/drivers/devfreq/governor.h +++ b/drivers/devfreq/governor.h @@ -68,6 +68,9 @@ extern int devfreq_add_governor(struct devfreq_governor *governor); extern int devfreq_remove_governor(struct devfreq_governor *governor); extern int devfreq_update_status(struct devfreq *devfreq, unsigned long freq); +extern void devfreq_update_transitions(struct devfreq *devfreq, + unsigned long old_freq, unsigned long new_freq, + unsigned long busy_time, unsigned long total_time); static inline int devfreq_update_stats(struct devfreq *df) { diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c index be6eeab9c814..05fa654239f5 100644 --- a/drivers/devfreq/governor_passive.c +++ b/drivers/devfreq/governor_passive.c @@ -109,6 +109,8 @@ static int update_devfreq_passive(struct devfreq *devfreq, unsigned long freq) if (ret < 0) goto out; + devfreq_update_transitions(devfreq, devfreq->previous_freq, freq, 0, 0); + if (devfreq->profile->freq_table && (devfreq_update_status(devfreq, freq))) dev_err(&devfreq->dev, diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h index 49cdb2378030..933692e5d867 100644 --- a/include/linux/devfreq.h +++ b/include/linux/devfreq.h @@ -196,6 +196,7 @@ struct devfreq { }; struct devfreq_freqs { + s64 time; unsigned long old; unsigned long new; };
Add new devfreq_transitions debugfs file to track the frequency transitions of all devfreq devices for the simple profiling as following: - /sys/kernel/debug/devfreq/devfreq_transitions And the user can decide the storage size (CONFIG_NR_DEVFREQ_TRANSITIONS) in Kconfig in order to save the transition history. [Detailed description of each field of 'devfreq_transitions' debugfs file] - time_ms : Change time of frequency transition. (unit: millisecond) - dev_name : Device name of h/w. - dev : Device name made by devfreq core. - parent_dev : If devfreq device uses the passive governor, show parent devfreq device name. - load_% : If devfreq device uses the simple_ondemand governor, load is used by governor whene deciding the new frequency. (unit: percentage) - old_freq_hz : Frequency before changing. (unit: hz) - new_freq_hz : Frequency after changed. (unit: hz) [For example on Exynos5422-based Odroid-XU3 board] $ cat /sys/kernel/debug/devfreq/devfreq_transitions time_ms dev_name dev parent_dev load_% old_freq_hz new_freq_hz ---------- ------------------------------ ---------- ---------- ---------- ------------ ------------ 14600 soc:bus_noc devfreq2 devfreq1 0 100000000 67000000 14600 soc:bus_fsys_apb devfreq3 devfreq1 0 200000000 100000000 14600 soc:bus_fsys devfreq4 devfreq1 0 200000000 100000000 14600 soc:bus_fsys2 devfreq5 devfreq1 0 150000000 75000000 14602 soc:bus_mfc devfreq6 devfreq1 0 222000000 96000000 14602 soc:bus_gen devfreq7 devfreq1 0 267000000 89000000 14602 soc:bus_g2d devfreq9 devfreq1 0 300000000 84000000 14602 soc:bus_g2d_acp devfreq10 devfreq1 0 267000000 67000000 14602 soc:bus_jpeg devfreq11 devfreq1 0 300000000 75000000 14602 soc:bus_jpeg_apb devfreq12 devfreq1 0 167000000 84000000 14603 soc:bus_disp1_fimd devfreq13 devfreq1 0 200000000 120000000 14603 soc:bus_disp1 devfreq14 devfreq1 0 300000000 120000000 14606 soc:bus_gscl_scaler devfreq15 devfreq1 0 300000000 150000000 14606 soc:bus_mscl devfreq16 devfreq1 0 333000000 84000000 14608 soc:bus_wcore devfreq1 9 333000000 84000000 14783 10c20000.memory-controller devfreq0 35 825000000 633000000 15873 soc:bus_wcore devfreq1 41 84000000 400000000 15873 soc:bus_noc devfreq2 devfreq1 0 67000000 100000000 [snip] Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> --- drivers/devfreq/Kconfig | 13 +++ drivers/devfreq/devfreq.c | 126 +++++++++++++++++++++++++++++ drivers/devfreq/governor.h | 3 + drivers/devfreq/governor_passive.c | 2 + include/linux/devfreq.h | 1 + 5 files changed, 145 insertions(+)