| Message ID | 20200114014540.31490-1-cw00.choi@samsung.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Chanwoo Choi |
| Headers | show |
| Series | [v3] PM / devfreq: Add debugfs support with devfreq_summary file | expand |
14.01.2020 04:45, Chanwoo Choi пишет: > Add debugfs interface to provide debugging information of devfreq device. > It contains 'devfreq_summary' entry to show the summary of registered > devfreq devices as following and the additional debugfs file will be added. > - /sys/kernel/debug/devfreq/devfreq_summary > > [Detailed description of each field of 'devfreq_summary' debugfs file] > - 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. Otherwise, show 'null'. > - governor : Devfreq governor. > - polling_ms : If devfreq device uses the simple_ondemand governor, > polling_ms is necessary for the period. (unit: millisecond) > - cur_freq_Hz : Current Frequency (unit: Hz) > - 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_summary > dev_name dev parent_dev governor polling_ms cur_freq_Hz min_freq_Hz max_freq_Hz > ------------------------------ ---------- ---------- --------------- ---------- ------------ ------------ ------------ > 10c20000.memory-controller devfreq0 null simple_ondemand 0 165000000 165000000 825000000 > soc:bus_wcore devfreq1 null simple_ondemand 50 532000000 88700000 532000000 > soc:bus_noc devfreq2 devfreq1 passive 0 111000000 66600000 111000000 > soc:bus_fsys_apb devfreq3 devfreq1 passive 0 222000000 111000000 222000000 > soc:bus_fsys devfreq4 devfreq1 passive 0 200000000 75000000 200000000 > soc:bus_fsys2 devfreq5 devfreq1 passive 0 200000000 75000000 200000000 > soc:bus_mfc devfreq6 devfreq1 passive 0 333000000 83250000 333000000 > soc:bus_gen devfreq7 devfreq1 passive 0 266000000 88700000 266000000 > soc:bus_peri devfreq8 devfreq1 passive 0 66600000 66600000 66600000 > soc:bus_g2d devfreq9 devfreq1 passive 0 333000000 83250000 333000000 > soc:bus_g2d_acp devfreq10 devfreq1 passive 0 266000000 66500000 266000000 > soc:bus_jpeg devfreq11 devfreq1 passive 0 300000000 75000000 300000000 > soc:bus_jpeg_apb devfreq12 devfreq1 passive 0 166500000 83250000 166500000 > soc:bus_disp1_fimd devfreq13 devfreq1 passive 0 200000000 120000000 200000000 > soc:bus_disp1 devfreq14 devfreq1 passive 0 300000000 120000000 300000000 > soc:bus_gscl_scaler devfreq15 devfreq1 passive 0 300000000 150000000 300000000 > soc:bus_mscl devfreq16 devfreq1 passive 0 666000000 84000000 666000000 > > [lkp: Reported the build error] > Reported-by: kbuild test robot <lkp@intel.com> > Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> > --- > Changes from v2: > - Show 'null' at 'parent_dev' field when governor of devfreq device > is not passive > Changes from v1: > - Drop the patch about 'devfreq_transitions' debugfs file > - Modify from 'hz' to 'Hz' > - Edit the indentation of 'devfreq_summary' when show summary > - Exchange sequence between PTR_ERR and IS_ERR when debugfs_create_dir > > drivers/devfreq/devfreq.c | 84 +++++++++++++++++++++++++++++++++++++++ > 1 file changed, 84 insertions(+) > > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c > index 89260b17598f..c5ef2d194b1b 100644 > --- a/drivers/devfreq/devfreq.c > +++ b/drivers/devfreq/devfreq.c > @@ -10,6 +10,7 @@ > #include <linux/kernel.h> > #include <linux/kmod.h> > #include <linux/sched.h> > +#include <linux/debugfs.h> > #include <linux/errno.h> > #include <linux/err.h> > #include <linux/init.h> > @@ -33,6 +34,7 @@ > #define HZ_PER_KHZ 1000 > > static struct class *devfreq_class; > +static struct dentry *devfreq_debugfs; > > /* > * devfreq core provides delayed work based load monitoring helper > @@ -1643,6 +1645,79 @@ static struct attribute *devfreq_attrs[] = { > }; > ATTRIBUTE_GROUPS(devfreq); > > +/** > + * devfreq_summary_show() - Show the summary of the devfreq devices > + * @s: seq_file instance to show the summary of devfreq devices > + * @data: not used > + * > + * Show the summary of the devfreq devices via 'devfreq_summary' debugfs file. > + * It helps that user can know the detailed information of the devfreq devices. > + * > + * Return 0 always because it shows the information without any data change. > + */ > +static int devfreq_summary_show(struct seq_file *s, void *data) > +{ > + struct devfreq *devfreq; > + struct devfreq *p_devfreq = NULL; > + unsigned long cur_freq, min_freq, max_freq; > + unsigned int polling_ms; > + > + seq_printf(s, "%-30s %-10s %-10s %-15s %10s %12s %12s %12s\n", > + "dev_name", > + "dev", > + "parent_dev", > + "governor", > + "polling_ms", > + "cur_freq_Hz", > + "min_freq_Hz", > + "max_freq_Hz"); > + seq_printf(s, "%30s %10s %10s %15s %10s %12s %12s %12s\n", > + "------------------------------", > + "----------", > + "----------", > + "---------------", > + "----------", > + "------------", > + "------------", > + "------------"); > + > + mutex_lock(&devfreq_list_lock); > + > + list_for_each_entry_reverse(devfreq, &devfreq_list, node) { > + 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; > + } > + > + mutex_lock(&devfreq->lock); > + cur_freq = devfreq->previous_freq, > + get_freq_range(devfreq, &min_freq, &max_freq); > + polling_ms = devfreq->profile->polling_ms, > + mutex_unlock(&devfreq->lock); > + > + seq_printf(s, > + "%-30s %-10s %-10s %-15s %10d %12ld %12ld %12ld\n", > + dev_name(devfreq->dev.parent), > + dev_name(&devfreq->dev), > + p_devfreq ? dev_name(&p_devfreq->dev) : "null", > + devfreq->governor_name, > + polling_ms, > + cur_freq, > + min_freq, > + max_freq); > + } > + > + mutex_unlock(&devfreq_list_lock); > + > + return 0; > +} > +DEFINE_SHOW_ATTRIBUTE(devfreq_summary); > + > static int __init devfreq_init(void) > { > devfreq_class = class_create(THIS_MODULE, "devfreq"); > @@ -1659,6 +1734,15 @@ static int __init devfreq_init(void) > } > devfreq_class->dev_groups = devfreq_groups; > > + devfreq_debugfs = debugfs_create_dir("devfreq", NULL); > + if (IS_ERR(devfreq_debugfs) && PTR_ERR(devfreq_debugfs) != -ENODEV) { > + pr_warn("%s: couldn't create debugfs dir\n", __FILE__); If you'll take a look at [1], you may notice that it could fail only in a single place in the code and in that case the error message is already printed. [1] https://elixir.bootlin.com/linux/v5.5-rc6/source/fs/debugfs/inode.c#L543 > + } else { > + debugfs_create_file("devfreq_summary", 0444, > + devfreq_debugfs, NULL, > + &devfreq_summary_fops); If you'll you'll take a look at [2], you may notice notice that it checks whether devfreq_debugfs IS_ERR [3] and then bails out. [2] https://elixir.bootlin.com/linux/v5.5-rc6/source/fs/debugfs/inode.c#L432 [3] https://elixir.bootlin.com/linux/v5.5-rc6/source/fs/debugfs/inode.c#L316 Thus you could simply remove the above error handling, making code to look cleaner.
On 1/14/20 10:45 AM, Dmitry Osipenko wrote: > 14.01.2020 04:45, Chanwoo Choi пишет: >> Add debugfs interface to provide debugging information of devfreq device. >> It contains 'devfreq_summary' entry to show the summary of registered >> devfreq devices as following and the additional debugfs file will be added. >> - /sys/kernel/debug/devfreq/devfreq_summary >> >> [Detailed description of each field of 'devfreq_summary' debugfs file] >> - 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. Otherwise, show 'null'. >> - governor : Devfreq governor. >> - polling_ms : If devfreq device uses the simple_ondemand governor, >> polling_ms is necessary for the period. (unit: millisecond) >> - cur_freq_Hz : Current Frequency (unit: Hz) >> - 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_summary >> dev_name dev parent_dev governor polling_ms cur_freq_Hz min_freq_Hz max_freq_Hz >> ------------------------------ ---------- ---------- --------------- ---------- ------------ ------------ ------------ >> 10c20000.memory-controller devfreq0 null simple_ondemand 0 165000000 165000000 825000000 >> soc:bus_wcore devfreq1 null simple_ondemand 50 532000000 88700000 532000000 >> soc:bus_noc devfreq2 devfreq1 passive 0 111000000 66600000 111000000 >> soc:bus_fsys_apb devfreq3 devfreq1 passive 0 222000000 111000000 222000000 >> soc:bus_fsys devfreq4 devfreq1 passive 0 200000000 75000000 200000000 >> soc:bus_fsys2 devfreq5 devfreq1 passive 0 200000000 75000000 200000000 >> soc:bus_mfc devfreq6 devfreq1 passive 0 333000000 83250000 333000000 >> soc:bus_gen devfreq7 devfreq1 passive 0 266000000 88700000 266000000 >> soc:bus_peri devfreq8 devfreq1 passive 0 66600000 66600000 66600000 >> soc:bus_g2d devfreq9 devfreq1 passive 0 333000000 83250000 333000000 >> soc:bus_g2d_acp devfreq10 devfreq1 passive 0 266000000 66500000 266000000 >> soc:bus_jpeg devfreq11 devfreq1 passive 0 300000000 75000000 300000000 >> soc:bus_jpeg_apb devfreq12 devfreq1 passive 0 166500000 83250000 166500000 >> soc:bus_disp1_fimd devfreq13 devfreq1 passive 0 200000000 120000000 200000000 >> soc:bus_disp1 devfreq14 devfreq1 passive 0 300000000 120000000 300000000 >> soc:bus_gscl_scaler devfreq15 devfreq1 passive 0 300000000 150000000 300000000 >> soc:bus_mscl devfreq16 devfreq1 passive 0 666000000 84000000 666000000 >> >> [lkp: Reported the build error] >> Reported-by: kbuild test robot <lkp@intel.com> >> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> >> --- >> Changes from v2: >> - Show 'null' at 'parent_dev' field when governor of devfreq device >> is not passive >> Changes from v1: >> - Drop the patch about 'devfreq_transitions' debugfs file >> - Modify from 'hz' to 'Hz' >> - Edit the indentation of 'devfreq_summary' when show summary >> - Exchange sequence between PTR_ERR and IS_ERR when debugfs_create_dir >> >> drivers/devfreq/devfreq.c | 84 +++++++++++++++++++++++++++++++++++++++ >> 1 file changed, 84 insertions(+) >> >> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c >> index 89260b17598f..c5ef2d194b1b 100644 >> --- a/drivers/devfreq/devfreq.c >> +++ b/drivers/devfreq/devfreq.c >> @@ -10,6 +10,7 @@ >> #include <linux/kernel.h> >> #include <linux/kmod.h> >> #include <linux/sched.h> >> +#include <linux/debugfs.h> >> #include <linux/errno.h> >> #include <linux/err.h> >> #include <linux/init.h> >> @@ -33,6 +34,7 @@ >> #define HZ_PER_KHZ 1000 >> >> static struct class *devfreq_class; >> +static struct dentry *devfreq_debugfs; >> >> /* >> * devfreq core provides delayed work based load monitoring helper >> @@ -1643,6 +1645,79 @@ static struct attribute *devfreq_attrs[] = { >> }; >> ATTRIBUTE_GROUPS(devfreq); >> >> +/** >> + * devfreq_summary_show() - Show the summary of the devfreq devices >> + * @s: seq_file instance to show the summary of devfreq devices >> + * @data: not used >> + * >> + * Show the summary of the devfreq devices via 'devfreq_summary' debugfs file. >> + * It helps that user can know the detailed information of the devfreq devices. >> + * >> + * Return 0 always because it shows the information without any data change. >> + */ >> +static int devfreq_summary_show(struct seq_file *s, void *data) >> +{ >> + struct devfreq *devfreq; >> + struct devfreq *p_devfreq = NULL; >> + unsigned long cur_freq, min_freq, max_freq; >> + unsigned int polling_ms; >> + >> + seq_printf(s, "%-30s %-10s %-10s %-15s %10s %12s %12s %12s\n", >> + "dev_name", >> + "dev", >> + "parent_dev", >> + "governor", >> + "polling_ms", >> + "cur_freq_Hz", >> + "min_freq_Hz", >> + "max_freq_Hz"); >> + seq_printf(s, "%30s %10s %10s %15s %10s %12s %12s %12s\n", >> + "------------------------------", >> + "----------", >> + "----------", >> + "---------------", >> + "----------", >> + "------------", >> + "------------", >> + "------------"); >> + >> + mutex_lock(&devfreq_list_lock); >> + >> + list_for_each_entry_reverse(devfreq, &devfreq_list, node) { >> + 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; >> + } >> + >> + mutex_lock(&devfreq->lock); >> + cur_freq = devfreq->previous_freq, >> + get_freq_range(devfreq, &min_freq, &max_freq); >> + polling_ms = devfreq->profile->polling_ms, >> + mutex_unlock(&devfreq->lock); >> + >> + seq_printf(s, >> + "%-30s %-10s %-10s %-15s %10d %12ld %12ld %12ld\n", >> + dev_name(devfreq->dev.parent), >> + dev_name(&devfreq->dev), >> + p_devfreq ? dev_name(&p_devfreq->dev) : "null", >> + devfreq->governor_name, >> + polling_ms, >> + cur_freq, >> + min_freq, >> + max_freq); >> + } >> + >> + mutex_unlock(&devfreq_list_lock); >> + >> + return 0; >> +} >> +DEFINE_SHOW_ATTRIBUTE(devfreq_summary); >> + >> static int __init devfreq_init(void) >> { >> devfreq_class = class_create(THIS_MODULE, "devfreq"); >> @@ -1659,6 +1734,15 @@ static int __init devfreq_init(void) >> } >> devfreq_class->dev_groups = devfreq_groups; >> >> + > If you'll you'll take a look at [2], you may notice notice that it > checks whether devfreq_debugfs IS_ERR [3] and then bails out. > > [2] https://protect2.fireeye.com/url?k=a5047d02-f8ca7cd1-a505f64d-000babff317b-ed64c541cd573190&u=https://elixir.bootlin.com/linux/v5.5-rc6/source/fs/debugfs/inode.c#L432 > [3] https://protect2.fireeye.com/url?k=0a43fffa-578dfe29-0a4274b5-000babff317b-1c1c1062bfaeb0fc&u=https://elixir.bootlin.com/linux/v5.5-rc6/source/fs/debugfs/inode.c#L316 > > Thus you could simply remove the above error handling, making code to > look cleaner. > > OK. I'll modify it as following: Do you agree? devfreq_debugfs = debugfs_create_dir("devfreq", NULL); debugfs_create_file("devfreq_summary", 0444, devfreq_debugfs, NULL, &devfreq_summary_fops);
14.01.2020 05:23, Chanwoo Choi пишет: > On 1/14/20 10:45 AM, Dmitry Osipenko wrote: >> 14.01.2020 04:45, Chanwoo Choi пишет: >>> Add debugfs interface to provide debugging information of devfreq device. >>> It contains 'devfreq_summary' entry to show the summary of registered >>> devfreq devices as following and the additional debugfs file will be added. >>> - /sys/kernel/debug/devfreq/devfreq_summary >>> >>> [Detailed description of each field of 'devfreq_summary' debugfs file] >>> - 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. Otherwise, show 'null'. >>> - governor : Devfreq governor. >>> - polling_ms : If devfreq device uses the simple_ondemand governor, >>> polling_ms is necessary for the period. (unit: millisecond) >>> - cur_freq_Hz : Current Frequency (unit: Hz) >>> - 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_summary >>> dev_name dev parent_dev governor polling_ms cur_freq_Hz min_freq_Hz max_freq_Hz >>> ------------------------------ ---------- ---------- --------------- ---------- ------------ ------------ ------------ >>> 10c20000.memory-controller devfreq0 null simple_ondemand 0 165000000 165000000 825000000 >>> soc:bus_wcore devfreq1 null simple_ondemand 50 532000000 88700000 532000000 >>> soc:bus_noc devfreq2 devfreq1 passive 0 111000000 66600000 111000000 >>> soc:bus_fsys_apb devfreq3 devfreq1 passive 0 222000000 111000000 222000000 >>> soc:bus_fsys devfreq4 devfreq1 passive 0 200000000 75000000 200000000 >>> soc:bus_fsys2 devfreq5 devfreq1 passive 0 200000000 75000000 200000000 >>> soc:bus_mfc devfreq6 devfreq1 passive 0 333000000 83250000 333000000 >>> soc:bus_gen devfreq7 devfreq1 passive 0 266000000 88700000 266000000 >>> soc:bus_peri devfreq8 devfreq1 passive 0 66600000 66600000 66600000 >>> soc:bus_g2d devfreq9 devfreq1 passive 0 333000000 83250000 333000000 >>> soc:bus_g2d_acp devfreq10 devfreq1 passive 0 266000000 66500000 266000000 >>> soc:bus_jpeg devfreq11 devfreq1 passive 0 300000000 75000000 300000000 >>> soc:bus_jpeg_apb devfreq12 devfreq1 passive 0 166500000 83250000 166500000 >>> soc:bus_disp1_fimd devfreq13 devfreq1 passive 0 200000000 120000000 200000000 >>> soc:bus_disp1 devfreq14 devfreq1 passive 0 300000000 120000000 300000000 >>> soc:bus_gscl_scaler devfreq15 devfreq1 passive 0 300000000 150000000 300000000 >>> soc:bus_mscl devfreq16 devfreq1 passive 0 666000000 84000000 666000000 >>> >>> [lkp: Reported the build error] >>> Reported-by: kbuild test robot <lkp@intel.com> >>> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> >>> --- >>> Changes from v2: >>> - Show 'null' at 'parent_dev' field when governor of devfreq device >>> is not passive >>> Changes from v1: >>> - Drop the patch about 'devfreq_transitions' debugfs file >>> - Modify from 'hz' to 'Hz' >>> - Edit the indentation of 'devfreq_summary' when show summary >>> - Exchange sequence between PTR_ERR and IS_ERR when debugfs_create_dir >>> >>> drivers/devfreq/devfreq.c | 84 +++++++++++++++++++++++++++++++++++++++ >>> 1 file changed, 84 insertions(+) >>> >>> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c >>> index 89260b17598f..c5ef2d194b1b 100644 >>> --- a/drivers/devfreq/devfreq.c >>> +++ b/drivers/devfreq/devfreq.c >>> @@ -10,6 +10,7 @@ >>> #include <linux/kernel.h> >>> #include <linux/kmod.h> >>> #include <linux/sched.h> >>> +#include <linux/debugfs.h> >>> #include <linux/errno.h> >>> #include <linux/err.h> >>> #include <linux/init.h> >>> @@ -33,6 +34,7 @@ >>> #define HZ_PER_KHZ 1000 >>> >>> static struct class *devfreq_class; >>> +static struct dentry *devfreq_debugfs; >>> >>> /* >>> * devfreq core provides delayed work based load monitoring helper >>> @@ -1643,6 +1645,79 @@ static struct attribute *devfreq_attrs[] = { >>> }; >>> ATTRIBUTE_GROUPS(devfreq); >>> >>> +/** >>> + * devfreq_summary_show() - Show the summary of the devfreq devices >>> + * @s: seq_file instance to show the summary of devfreq devices >>> + * @data: not used >>> + * >>> + * Show the summary of the devfreq devices via 'devfreq_summary' debugfs file. >>> + * It helps that user can know the detailed information of the devfreq devices. >>> + * >>> + * Return 0 always because it shows the information without any data change. >>> + */ >>> +static int devfreq_summary_show(struct seq_file *s, void *data) >>> +{ >>> + struct devfreq *devfreq; >>> + struct devfreq *p_devfreq = NULL; Looks like there is no need to pre-initialize the p_devfreq, please see below. >>> + unsigned long cur_freq, min_freq, max_freq; >>> + unsigned int polling_ms; >>> + >>> + seq_printf(s, "%-30s %-10s %-10s %-15s %10s %12s %12s %12s\n", >>> + "dev_name", >>> + "dev", >>> + "parent_dev", >>> + "governor", >>> + "polling_ms", >>> + "cur_freq_Hz", >>> + "min_freq_Hz", >>> + "max_freq_Hz"); >>> + seq_printf(s, "%30s %10s %10s %15s %10s %12s %12s %12s\n", >>> + "------------------------------", >>> + "----------", >>> + "----------", >>> + "---------------", >>> + "----------", >>> + "------------", >>> + "------------", >>> + "------------"); >>> + >>> + mutex_lock(&devfreq_list_lock); >>> + >>> + list_for_each_entry_reverse(devfreq, &devfreq_list, node) { >>> + 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; Otherwise p_devfreq will be reused from a previous devfreq device if that device has the data->parent. >>> + } else { >>> + p_devfreq = NULL; >>> + } >>> + >>> + mutex_lock(&devfreq->lock); >>> + cur_freq = devfreq->previous_freq, >>> + get_freq_range(devfreq, &min_freq, &max_freq); >>> + polling_ms = devfreq->profile->polling_ms, >>> + mutex_unlock(&devfreq->lock); >>> + >>> + seq_printf(s, >>> + "%-30s %-10s %-10s %-15s %10d %12ld %12ld %12ld\n", >>> + dev_name(devfreq->dev.parent), >>> + dev_name(&devfreq->dev), >>> + p_devfreq ? dev_name(&p_devfreq->dev) : "null", >>> + devfreq->governor_name, >>> + polling_ms, >>> + cur_freq, >>> + min_freq, >>> + max_freq); >>> + } >>> + >>> + mutex_unlock(&devfreq_list_lock); >>> + >>> + return 0; >>> +} >>> +DEFINE_SHOW_ATTRIBUTE(devfreq_summary); >>> + >>> static int __init devfreq_init(void) >>> { >>> devfreq_class = class_create(THIS_MODULE, "devfreq"); >>> @@ -1659,6 +1734,15 @@ static int __init devfreq_init(void) >>> } >>> devfreq_class->dev_groups = devfreq_groups; >>> >>> + >> If you'll you'll take a look at [2], you may notice notice that it >> checks whether devfreq_debugfs IS_ERR [3] and then bails out. >> >> [2] https://protect2.fireeye.com/url?k=a5047d02-f8ca7cd1-a505f64d-000babff317b-ed64c541cd573190&u=https://elixir.bootlin.com/linux/v5.5-rc6/source/fs/debugfs/inode.c#L432 >> [3] https://protect2.fireeye.com/url?k=0a43fffa-578dfe29-0a4274b5-000babff317b-1c1c1062bfaeb0fc&u=https://elixir.bootlin.com/linux/v5.5-rc6/source/fs/debugfs/inode.c#L316 >> >> Thus you could simply remove the above error handling, making code to >> look cleaner. >> >> > > OK. I'll modify it as following: Do you agree? Looks good, thanks. > devfreq_debugfs = debugfs_create_dir("devfreq", NULL); I'd also add a newline here, to ease reading of the code. > debugfs_create_file("devfreq_summary", 0444, > devfreq_debugfs, NULL, > &devfreq_summary_fops); > >
On 1/14/20 11:51 AM, Dmitry Osipenko wrote: > 14.01.2020 05:23, Chanwoo Choi пишет: >> On 1/14/20 10:45 AM, Dmitry Osipenko wrote: >>> 14.01.2020 04:45, Chanwoo Choi пишет: >>>> Add debugfs interface to provide debugging information of devfreq device. >>>> It contains 'devfreq_summary' entry to show the summary of registered >>>> devfreq devices as following and the additional debugfs file will be added. >>>> - /sys/kernel/debug/devfreq/devfreq_summary >>>> >>>> [Detailed description of each field of 'devfreq_summary' debugfs file] >>>> - 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. Otherwise, show 'null'. >>>> - governor : Devfreq governor. >>>> - polling_ms : If devfreq device uses the simple_ondemand governor, >>>> polling_ms is necessary for the period. (unit: millisecond) >>>> - cur_freq_Hz : Current Frequency (unit: Hz) >>>> - 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_summary >>>> dev_name dev parent_dev governor polling_ms cur_freq_Hz min_freq_Hz max_freq_Hz >>>> ------------------------------ ---------- ---------- --------------- ---------- ------------ ------------ ------------ >>>> 10c20000.memory-controller devfreq0 null simple_ondemand 0 165000000 165000000 825000000 >>>> soc:bus_wcore devfreq1 null simple_ondemand 50 532000000 88700000 532000000 >>>> soc:bus_noc devfreq2 devfreq1 passive 0 111000000 66600000 111000000 >>>> soc:bus_fsys_apb devfreq3 devfreq1 passive 0 222000000 111000000 222000000 >>>> soc:bus_fsys devfreq4 devfreq1 passive 0 200000000 75000000 200000000 >>>> soc:bus_fsys2 devfreq5 devfreq1 passive 0 200000000 75000000 200000000 >>>> soc:bus_mfc devfreq6 devfreq1 passive 0 333000000 83250000 333000000 >>>> soc:bus_gen devfreq7 devfreq1 passive 0 266000000 88700000 266000000 >>>> soc:bus_peri devfreq8 devfreq1 passive 0 66600000 66600000 66600000 >>>> soc:bus_g2d devfreq9 devfreq1 passive 0 333000000 83250000 333000000 >>>> soc:bus_g2d_acp devfreq10 devfreq1 passive 0 266000000 66500000 266000000 >>>> soc:bus_jpeg devfreq11 devfreq1 passive 0 300000000 75000000 300000000 >>>> soc:bus_jpeg_apb devfreq12 devfreq1 passive 0 166500000 83250000 166500000 >>>> soc:bus_disp1_fimd devfreq13 devfreq1 passive 0 200000000 120000000 200000000 >>>> soc:bus_disp1 devfreq14 devfreq1 passive 0 300000000 120000000 300000000 >>>> soc:bus_gscl_scaler devfreq15 devfreq1 passive 0 300000000 150000000 300000000 >>>> soc:bus_mscl devfreq16 devfreq1 passive 0 666000000 84000000 666000000 >>>> >>>> [lkp: Reported the build error] >>>> Reported-by: kbuild test robot <lkp@intel.com> >>>> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> >>>> --- >>>> Changes from v2: >>>> - Show 'null' at 'parent_dev' field when governor of devfreq device >>>> is not passive >>>> Changes from v1: >>>> - Drop the patch about 'devfreq_transitions' debugfs file >>>> - Modify from 'hz' to 'Hz' >>>> - Edit the indentation of 'devfreq_summary' when show summary >>>> - Exchange sequence between PTR_ERR and IS_ERR when debugfs_create_dir >>>> >>>> drivers/devfreq/devfreq.c | 84 +++++++++++++++++++++++++++++++++++++++ >>>> 1 file changed, 84 insertions(+) >>>> >>>> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c >>>> index 89260b17598f..c5ef2d194b1b 100644 >>>> --- a/drivers/devfreq/devfreq.c >>>> +++ b/drivers/devfreq/devfreq.c >>>> @@ -10,6 +10,7 @@ >>>> #include <linux/kernel.h> >>>> #include <linux/kmod.h> >>>> #include <linux/sched.h> >>>> +#include <linux/debugfs.h> >>>> #include <linux/errno.h> >>>> #include <linux/err.h> >>>> #include <linux/init.h> >>>> @@ -33,6 +34,7 @@ >>>> #define HZ_PER_KHZ 1000 >>>> >>>> static struct class *devfreq_class; >>>> +static struct dentry *devfreq_debugfs; >>>> >>>> /* >>>> * devfreq core provides delayed work based load monitoring helper >>>> @@ -1643,6 +1645,79 @@ static struct attribute *devfreq_attrs[] = { >>>> }; >>>> ATTRIBUTE_GROUPS(devfreq); >>>> >>>> +/** >>>> + * devfreq_summary_show() - Show the summary of the devfreq devices >>>> + * @s: seq_file instance to show the summary of devfreq devices >>>> + * @data: not used >>>> + * >>>> + * Show the summary of the devfreq devices via 'devfreq_summary' debugfs file. >>>> + * It helps that user can know the detailed information of the devfreq devices. >>>> + * >>>> + * Return 0 always because it shows the information without any data change. >>>> + */ >>>> +static int devfreq_summary_show(struct seq_file *s, void *data) >>>> +{ >>>> + struct devfreq *devfreq; >>>> + struct devfreq *p_devfreq = NULL; > > Looks like there is no need to pre-initialize the p_devfreq, please see > below. > >>>> + unsigned long cur_freq, min_freq, max_freq; >>>> + unsigned int polling_ms; >>>> + >>>> + seq_printf(s, "%-30s %-10s %-10s %-15s %10s %12s %12s %12s\n", >>>> + "dev_name", >>>> + "dev", >>>> + "parent_dev", >>>> + "governor", >>>> + "polling_ms", >>>> + "cur_freq_Hz", >>>> + "min_freq_Hz", >>>> + "max_freq_Hz"); >>>> + seq_printf(s, "%30s %10s %10s %15s %10s %12s %12s %12s\n", >>>> + "------------------------------", >>>> + "----------", >>>> + "----------", >>>> + "---------------", >>>> + "----------", >>>> + "------------", >>>> + "------------", >>>> + "------------"); >>>> + >>>> + mutex_lock(&devfreq_list_lock); >>>> + >>>> + list_for_each_entry_reverse(devfreq, &devfreq_list, node) { #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; > > Otherwise p_devfreq will be reused from a previous devfreq device if > that device has the data->parent. This path has the problem. I'm missing that. 'struct devfreq_passive_data' is only defined when CONFIG_DEVFREQ_GOV_PASSIVE is enabled. In case of when CONFIG_DEVFREQ_GOV_PASSIVE is disabled, p_devfreq should be initialized with NULL as following: I'll modify this patch as following: struct devfreq *p_devfreq = NULL; #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 > >>>> + } else { >>>> + p_devfreq = NULL; >>>> + } >>>> + >>>> + mutex_lock(&devfreq->lock); >>>> + cur_freq = devfreq->previous_freq, >>>> + get_freq_range(devfreq, &min_freq, &max_freq); >>>> + polling_ms = devfreq->profile->polling_ms, >>>> + mutex_unlock(&devfreq->lock); >>>> + >>>> + seq_printf(s, >>>> + "%-30s %-10s %-10s %-15s %10d %12ld %12ld %12ld\n", >>>> + dev_name(devfreq->dev.parent), >>>> + dev_name(&devfreq->dev), >>>> + p_devfreq ? dev_name(&p_devfreq->dev) : "null", >>>> + devfreq->governor_name, >>>> + polling_ms, >>>> + cur_freq, >>>> + min_freq, >>>> + max_freq); >>>> + } >>>> + >>>> + mutex_unlock(&devfreq_list_lock); >>>> + >>>> + return 0; >>>> +} >>>> +DEFINE_SHOW_ATTRIBUTE(devfreq_summary); >>>> + >>>> static int __init devfreq_init(void) >>>> { >>>> devfreq_class = class_create(THIS_MODULE, "devfreq"); >>>> @@ -1659,6 +1734,15 @@ static int __init devfreq_init(void) >>>> } >>>> devfreq_class->dev_groups = devfreq_groups; >>>> >>>> + >>> If you'll you'll take a look at [2], you may notice notice that it >>> checks whether devfreq_debugfs IS_ERR [3] and then bails out. >>> >>> [2] https://protect2.fireeye.com/url?k=a5047d02-f8ca7cd1-a505f64d-000babff317b-ed64c541cd573190&u=https://elixir.bootlin.com/linux/v5.5-rc6/source/fs/debugfs/inode.c#L432 >>> [3] https://protect2.fireeye.com/url?k=0a43fffa-578dfe29-0a4274b5-000babff317b-1c1c1062bfaeb0fc&u=https://elixir.bootlin.com/linux/v5.5-rc6/source/fs/debugfs/inode.c#L316 >>> >>> Thus you could simply remove the above error handling, making code to >>> look cleaner. >>> >>> >> >> OK. I'll modify it as following: Do you agree? > > Looks good, thanks. > >> devfreq_debugfs = debugfs_create_dir("devfreq", NULL); > > I'd also add a newline here, to ease reading of the code. ok. > >> debugfs_create_file("devfreq_summary", 0444, >> devfreq_debugfs, NULL, >> &devfreq_summary_fops); >> >> > > >
On 1/14/20 1:02 PM, Chanwoo Choi wrote: > On 1/14/20 11:51 AM, Dmitry Osipenko wrote: >> 14.01.2020 05:23, Chanwoo Choi пишет: >>> On 1/14/20 10:45 AM, Dmitry Osipenko wrote: >>>> 14.01.2020 04:45, Chanwoo Choi пишет: >>>>> Add debugfs interface to provide debugging information of devfreq device. >>>>> It contains 'devfreq_summary' entry to show the summary of registered >>>>> devfreq devices as following and the additional debugfs file will be added. >>>>> - /sys/kernel/debug/devfreq/devfreq_summary >>>>> >>>>> [Detailed description of each field of 'devfreq_summary' debugfs file] >>>>> - 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. Otherwise, show 'null'. >>>>> - governor : Devfreq governor. >>>>> - polling_ms : If devfreq device uses the simple_ondemand governor, >>>>> polling_ms is necessary for the period. (unit: millisecond) >>>>> - cur_freq_Hz : Current Frequency (unit: Hz) >>>>> - 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_summary >>>>> dev_name dev parent_dev governor polling_ms cur_freq_Hz min_freq_Hz max_freq_Hz >>>>> ------------------------------ ---------- ---------- --------------- ---------- ------------ ------------ ------------ >>>>> 10c20000.memory-controller devfreq0 null simple_ondemand 0 165000000 165000000 825000000 >>>>> soc:bus_wcore devfreq1 null simple_ondemand 50 532000000 88700000 532000000 >>>>> soc:bus_noc devfreq2 devfreq1 passive 0 111000000 66600000 111000000 >>>>> soc:bus_fsys_apb devfreq3 devfreq1 passive 0 222000000 111000000 222000000 >>>>> soc:bus_fsys devfreq4 devfreq1 passive 0 200000000 75000000 200000000 >>>>> soc:bus_fsys2 devfreq5 devfreq1 passive 0 200000000 75000000 200000000 >>>>> soc:bus_mfc devfreq6 devfreq1 passive 0 333000000 83250000 333000000 >>>>> soc:bus_gen devfreq7 devfreq1 passive 0 266000000 88700000 266000000 >>>>> soc:bus_peri devfreq8 devfreq1 passive 0 66600000 66600000 66600000 >>>>> soc:bus_g2d devfreq9 devfreq1 passive 0 333000000 83250000 333000000 >>>>> soc:bus_g2d_acp devfreq10 devfreq1 passive 0 266000000 66500000 266000000 >>>>> soc:bus_jpeg devfreq11 devfreq1 passive 0 300000000 75000000 300000000 >>>>> soc:bus_jpeg_apb devfreq12 devfreq1 passive 0 166500000 83250000 166500000 >>>>> soc:bus_disp1_fimd devfreq13 devfreq1 passive 0 200000000 120000000 200000000 >>>>> soc:bus_disp1 devfreq14 devfreq1 passive 0 300000000 120000000 300000000 >>>>> soc:bus_gscl_scaler devfreq15 devfreq1 passive 0 300000000 150000000 300000000 >>>>> soc:bus_mscl devfreq16 devfreq1 passive 0 666000000 84000000 666000000 >>>>> >>>>> [lkp: Reported the build error] >>>>> Reported-by: kbuild test robot <lkp@intel.com> >>>>> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> >>>>> --- >>>>> Changes from v2: >>>>> - Show 'null' at 'parent_dev' field when governor of devfreq device >>>>> is not passive >>>>> Changes from v1: >>>>> - Drop the patch about 'devfreq_transitions' debugfs file >>>>> - Modify from 'hz' to 'Hz' >>>>> - Edit the indentation of 'devfreq_summary' when show summary >>>>> - Exchange sequence between PTR_ERR and IS_ERR when debugfs_create_dir >>>>> >>>>> drivers/devfreq/devfreq.c | 84 +++++++++++++++++++++++++++++++++++++++ >>>>> 1 file changed, 84 insertions(+) >>>>> >>>>> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c >>>>> index 89260b17598f..c5ef2d194b1b 100644 >>>>> --- a/drivers/devfreq/devfreq.c >>>>> +++ b/drivers/devfreq/devfreq.c >>>>> @@ -10,6 +10,7 @@ >>>>> #include <linux/kernel.h> >>>>> #include <linux/kmod.h> >>>>> #include <linux/sched.h> >>>>> +#include <linux/debugfs.h> >>>>> #include <linux/errno.h> >>>>> #include <linux/err.h> >>>>> #include <linux/init.h> >>>>> @@ -33,6 +34,7 @@ >>>>> #define HZ_PER_KHZ 1000 >>>>> >>>>> static struct class *devfreq_class; >>>>> +static struct dentry *devfreq_debugfs; >>>>> >>>>> /* >>>>> * devfreq core provides delayed work based load monitoring helper >>>>> @@ -1643,6 +1645,79 @@ static struct attribute *devfreq_attrs[] = { >>>>> }; >>>>> ATTRIBUTE_GROUPS(devfreq); >>>>> >>>>> +/** >>>>> + * devfreq_summary_show() - Show the summary of the devfreq devices >>>>> + * @s: seq_file instance to show the summary of devfreq devices >>>>> + * @data: not used >>>>> + * >>>>> + * Show the summary of the devfreq devices via 'devfreq_summary' debugfs file. >>>>> + * It helps that user can know the detailed information of the devfreq devices. >>>>> + * >>>>> + * Return 0 always because it shows the information without any data change. >>>>> + */ >>>>> +static int devfreq_summary_show(struct seq_file *s, void *data) >>>>> +{ >>>>> + struct devfreq *devfreq; >>>>> + struct devfreq *p_devfreq = NULL; >> >> Looks like there is no need to pre-initialize the p_devfreq, please see >> below. >> >>>>> + unsigned long cur_freq, min_freq, max_freq; >>>>> + unsigned int polling_ms; >>>>> + >>>>> + seq_printf(s, "%-30s %-10s %-10s %-15s %10s %12s %12s %12s\n", >>>>> + "dev_name", >>>>> + "dev", >>>>> + "parent_dev", >>>>> + "governor", >>>>> + "polling_ms", >>>>> + "cur_freq_Hz", >>>>> + "min_freq_Hz", >>>>> + "max_freq_Hz"); >>>>> + seq_printf(s, "%30s %10s %10s %15s %10s %12s %12s %12s\n", >>>>> + "------------------------------", >>>>> + "----------", >>>>> + "----------", >>>>> + "---------------", >>>>> + "----------", >>>>> + "------------", >>>>> + "------------", >>>>> + "------------"); >>>>> + >>>>> + mutex_lock(&devfreq_list_lock); >>>>> + >>>>> + list_for_each_entry_reverse(devfreq, &devfreq_list, node) { > > #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; >> >> Otherwise p_devfreq will be reused from a previous devfreq device if >> that device has the data->parent. > > This path has the problem. I'm missing that. > > 'struct devfreq_passive_data' is only defined > when CONFIG_DEVFREQ_GOV_PASSIVE is enabled. > > In case of when CONFIG_DEVFREQ_GOV_PASSIVE is disabled, > p_devfreq should be initialized with NULL as following: > I'll modify this patch as following: > > struct devfreq *p_devfreq = NULL; > > #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 > > >> >>>>> + } else { >>>>> + p_devfreq = NULL; >>>>> + } >>>>> + >>>>> + mutex_lock(&devfreq->lock); >>>>> + cur_freq = devfreq->previous_freq, >>>>> + get_freq_range(devfreq, &min_freq, &max_freq); >>>>> + polling_ms = devfreq->profile->polling_ms, >>>>> + mutex_unlock(&devfreq->lock); >>>>> + >>>>> + seq_printf(s, >>>>> + "%-30s %-10s %-10s %-15s %10d %12ld %12ld %12ld\n", >>>>> + dev_name(devfreq->dev.parent), >>>>> + dev_name(&devfreq->dev), >>>>> + p_devfreq ? dev_name(&p_devfreq->dev) : "null", >>>>> + devfreq->governor_name, >>>>> + polling_ms, >>>>> + cur_freq, >>>>> + min_freq, >>>>> + max_freq); >>>>> + } >>>>> + >>>>> + mutex_unlock(&devfreq_list_lock); >>>>> + >>>>> + return 0; >>>>> +} >>>>> +DEFINE_SHOW_ATTRIBUTE(devfreq_summary); >>>>> + >>>>> static int __init devfreq_init(void) >>>>> { >>>>> devfreq_class = class_create(THIS_MODULE, "devfreq"); >>>>> @@ -1659,6 +1734,15 @@ static int __init devfreq_init(void) >>>>> } >>>>> devfreq_class->dev_groups = devfreq_groups; >>>>> >>>>> + >>>> If you'll you'll take a look at [2], you may notice notice that it >>>> checks whether devfreq_debugfs IS_ERR [3] and then bails out. >>>> >>>> [2] https://protect2.fireeye.com/url?k=a5047d02-f8ca7cd1-a505f64d-000babff317b-ed64c541cd573190&u=https://elixir.bootlin.com/linux/v5.5-rc6/source/fs/debugfs/inode.c#L432 >>>> [3] https://protect2.fireeye.com/url?k=0a43fffa-578dfe29-0a4274b5-000babff317b-1c1c1062bfaeb0fc&u=https://elixir.bootlin.com/linux/v5.5-rc6/source/fs/debugfs/inode.c#L316 >>>> >>>> Thus you could simply remove the above error handling, making code to >>>> look cleaner. >>>> >>>> >>> >>> OK. I'll modify it as following: Do you agree? >> >> Looks good, thanks. >> >>> devfreq_debugfs = debugfs_create_dir("devfreq", NULL); >> >> I'd also add a newline here, to ease reading of the code. > > ok. > >> >>> debugfs_create_file("devfreq_summary", 0444, >>> devfreq_debugfs, NULL, >>> &devfreq_summary_fops); Because there is not checking of return value, I think that it is more proper instead of adding the newline between debugfs_create_dir and debugfs_create_file. devfreq_debugfs = debugfs_create_dir("devfreq", NULL); debugfs_create_file("devfreq_summary", 0444, devfreq_debugfs, NULL, &devfreq_summary_fops); >>> >>> >> >> >> > >
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 89260b17598f..c5ef2d194b1b 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -10,6 +10,7 @@ #include <linux/kernel.h> #include <linux/kmod.h> #include <linux/sched.h> +#include <linux/debugfs.h> #include <linux/errno.h> #include <linux/err.h> #include <linux/init.h> @@ -33,6 +34,7 @@ #define HZ_PER_KHZ 1000 static struct class *devfreq_class; +static struct dentry *devfreq_debugfs; /* * devfreq core provides delayed work based load monitoring helper @@ -1643,6 +1645,79 @@ static struct attribute *devfreq_attrs[] = { }; ATTRIBUTE_GROUPS(devfreq); +/** + * devfreq_summary_show() - Show the summary of the devfreq devices + * @s: seq_file instance to show the summary of devfreq devices + * @data: not used + * + * Show the summary of the devfreq devices via 'devfreq_summary' debugfs file. + * It helps that user can know the detailed information of the devfreq devices. + * + * Return 0 always because it shows the information without any data change. + */ +static int devfreq_summary_show(struct seq_file *s, void *data) +{ + struct devfreq *devfreq; + struct devfreq *p_devfreq = NULL; + unsigned long cur_freq, min_freq, max_freq; + unsigned int polling_ms; + + seq_printf(s, "%-30s %-10s %-10s %-15s %10s %12s %12s %12s\n", + "dev_name", + "dev", + "parent_dev", + "governor", + "polling_ms", + "cur_freq_Hz", + "min_freq_Hz", + "max_freq_Hz"); + seq_printf(s, "%30s %10s %10s %15s %10s %12s %12s %12s\n", + "------------------------------", + "----------", + "----------", + "---------------", + "----------", + "------------", + "------------", + "------------"); + + mutex_lock(&devfreq_list_lock); + + list_for_each_entry_reverse(devfreq, &devfreq_list, node) { + 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; + } + + mutex_lock(&devfreq->lock); + cur_freq = devfreq->previous_freq, + get_freq_range(devfreq, &min_freq, &max_freq); + polling_ms = devfreq->profile->polling_ms, + mutex_unlock(&devfreq->lock); + + seq_printf(s, + "%-30s %-10s %-10s %-15s %10d %12ld %12ld %12ld\n", + dev_name(devfreq->dev.parent), + dev_name(&devfreq->dev), + p_devfreq ? dev_name(&p_devfreq->dev) : "null", + devfreq->governor_name, + polling_ms, + cur_freq, + min_freq, + max_freq); + } + + mutex_unlock(&devfreq_list_lock); + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(devfreq_summary); + static int __init devfreq_init(void) { devfreq_class = class_create(THIS_MODULE, "devfreq"); @@ -1659,6 +1734,15 @@ static int __init devfreq_init(void) } devfreq_class->dev_groups = devfreq_groups; + devfreq_debugfs = debugfs_create_dir("devfreq", NULL); + if (IS_ERR(devfreq_debugfs) && PTR_ERR(devfreq_debugfs) != -ENODEV) { + pr_warn("%s: couldn't create debugfs dir\n", __FILE__); + } else { + debugfs_create_file("devfreq_summary", 0444, + devfreq_debugfs, NULL, + &devfreq_summary_fops); + } + return 0; } subsys_initcall(devfreq_init);
Add debugfs interface to provide debugging information of devfreq device. It contains 'devfreq_summary' entry to show the summary of registered devfreq devices as following and the additional debugfs file will be added. - /sys/kernel/debug/devfreq/devfreq_summary [Detailed description of each field of 'devfreq_summary' debugfs file] - 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. Otherwise, show 'null'. - governor : Devfreq governor. - polling_ms : If devfreq device uses the simple_ondemand governor, polling_ms is necessary for the period. (unit: millisecond) - cur_freq_Hz : Current Frequency (unit: Hz) - 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_summary dev_name dev parent_dev governor polling_ms cur_freq_Hz min_freq_Hz max_freq_Hz ------------------------------ ---------- ---------- --------------- ---------- ------------ ------------ ------------ 10c20000.memory-controller devfreq0 null simple_ondemand 0 165000000 165000000 825000000 soc:bus_wcore devfreq1 null simple_ondemand 50 532000000 88700000 532000000 soc:bus_noc devfreq2 devfreq1 passive 0 111000000 66600000 111000000 soc:bus_fsys_apb devfreq3 devfreq1 passive 0 222000000 111000000 222000000 soc:bus_fsys devfreq4 devfreq1 passive 0 200000000 75000000 200000000 soc:bus_fsys2 devfreq5 devfreq1 passive 0 200000000 75000000 200000000 soc:bus_mfc devfreq6 devfreq1 passive 0 333000000 83250000 333000000 soc:bus_gen devfreq7 devfreq1 passive 0 266000000 88700000 266000000 soc:bus_peri devfreq8 devfreq1 passive 0 66600000 66600000 66600000 soc:bus_g2d devfreq9 devfreq1 passive 0 333000000 83250000 333000000 soc:bus_g2d_acp devfreq10 devfreq1 passive 0 266000000 66500000 266000000 soc:bus_jpeg devfreq11 devfreq1 passive 0 300000000 75000000 300000000 soc:bus_jpeg_apb devfreq12 devfreq1 passive 0 166500000 83250000 166500000 soc:bus_disp1_fimd devfreq13 devfreq1 passive 0 200000000 120000000 200000000 soc:bus_disp1 devfreq14 devfreq1 passive 0 300000000 120000000 300000000 soc:bus_gscl_scaler devfreq15 devfreq1 passive 0 300000000 150000000 300000000 soc:bus_mscl devfreq16 devfreq1 passive 0 666000000 84000000 666000000 [lkp: Reported the build error] Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> --- Changes from v2: - Show 'null' at 'parent_dev' field when governor of devfreq device is not passive Changes from v1: - Drop the patch about 'devfreq_transitions' debugfs file - Modify from 'hz' to 'Hz' - Edit the indentation of 'devfreq_summary' when show summary - Exchange sequence between PTR_ERR and IS_ERR when debugfs_create_dir drivers/devfreq/devfreq.c | 84 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 84 insertions(+)