| Message ID | 20190122164247.19439-1-quentin.perret@arm.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Delegated to: | Rafael Wysocki |
| Headers | show |
| Series | [v2] PM / EM: Expose the Energy Model in debugfs | expand |
On Tue, Jan 22, 2019 at 04:42:47PM +0000, Quentin Perret wrote: > The recently introduced Energy Model (EM) framework manages power cost > tables of CPUs. These tables are currently only visible from kernel > space. However, in order to debug the behaviour of subsystems that use > the EM (EAS for example), it is often required to know what the power > costs are from userspace. > > For this reason, introduce under /sys/kernel/debug/energy_model a set of > directories representing the performance domains of the system. Each > performance domain contains a set of sub-directories representing the > different capacity states (cs) and their attributes, as well as a file > exposing the related CPUs. > > The resulting hierarchy is as follows on Arm juno r0 for example: > > /sys/kernel/debug/energy_model > ├── pd0 > │ ├── cpus > │ ├── cs:450000 > │ │ ├── cost > │ │ ├── frequency > │ │ └── power > │ ├── cs:575000 > │ │ ├── cost > │ │ ├── frequency > │ │ └── power > │ ├── cs:700000 > │ │ ├── cost > │ │ ├── frequency > │ │ └── power > │ ├── cs:775000 > │ │ ├── cost > │ │ ├── frequency > │ │ └── power > │ └── cs:850000 > │ ├── cost > │ ├── frequency > │ └── power > └── pd1 > ├── cpus > ├── cs:1100000 > │ ├── cost > │ ├── frequency > │ └── power > ├── cs:450000 > │ ├── cost > │ ├── frequency > │ └── power > ├── cs:625000 > │ ├── cost > │ ├── frequency > │ └── power > ├── cs:800000 > │ ├── cost > │ ├── frequency > │ └── power > └── cs:950000 > ├── cost > ├── frequency > └── power > > Signed-off-by: Quentin Perret <quentin.perret@arm.com> > > --- > > V2: removed check on return value of debugfs_create_* (Greg KH) > --- > kernel/power/energy_model.c | 57 +++++++++++++++++++++++++++++++++++++ > 1 file changed, 57 insertions(+) Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On Tuesday 22 Jan 2019 at 19:41:36 (+0100), Greg KH wrote: > On Tue, Jan 22, 2019 at 04:42:47PM +0000, Quentin Perret wrote: > > The recently introduced Energy Model (EM) framework manages power cost > > tables of CPUs. These tables are currently only visible from kernel > > space. However, in order to debug the behaviour of subsystems that use > > the EM (EAS for example), it is often required to know what the power > > costs are from userspace. > > > > For this reason, introduce under /sys/kernel/debug/energy_model a set of > > directories representing the performance domains of the system. Each > > performance domain contains a set of sub-directories representing the > > different capacity states (cs) and their attributes, as well as a file > > exposing the related CPUs. > > > > The resulting hierarchy is as follows on Arm juno r0 for example: > > > > /sys/kernel/debug/energy_model > > ├── pd0 > > │ ├── cpus > > │ ├── cs:450000 > > │ │ ├── cost > > │ │ ├── frequency > > │ │ └── power > > │ ├── cs:575000 > > │ │ ├── cost > > │ │ ├── frequency > > │ │ └── power > > │ ├── cs:700000 > > │ │ ├── cost > > │ │ ├── frequency > > │ │ └── power > > │ ├── cs:775000 > > │ │ ├── cost > > │ │ ├── frequency > > │ │ └── power > > │ └── cs:850000 > > │ ├── cost > > │ ├── frequency > > │ └── power > > └── pd1 > > ├── cpus > > ├── cs:1100000 > > │ ├── cost > > │ ├── frequency > > │ └── power > > ├── cs:450000 > > │ ├── cost > > │ ├── frequency > > │ └── power > > ├── cs:625000 > > │ ├── cost > > │ ├── frequency > > │ └── power > > ├── cs:800000 > > │ ├── cost > > │ ├── frequency > > │ └── power > > └── cs:950000 > > ├── cost > > ├── frequency > > └── power > > > > Signed-off-by: Quentin Perret <quentin.perret@arm.com> > > > > --- > > > > V2: removed check on return value of debugfs_create_* (Greg KH) > > --- > > kernel/power/energy_model.c | 57 +++++++++++++++++++++++++++++++++++++ > > 1 file changed, 57 insertions(+) > > Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Thanks ! Quentin
On Wednesday, January 23, 2019 10:28:36 AM CET Quentin Perret wrote: > On Tuesday 22 Jan 2019 at 19:41:36 (+0100), Greg KH wrote: > > On Tue, Jan 22, 2019 at 04:42:47PM +0000, Quentin Perret wrote: > > > The recently introduced Energy Model (EM) framework manages power cost > > > tables of CPUs. These tables are currently only visible from kernel > > > space. However, in order to debug the behaviour of subsystems that use > > > the EM (EAS for example), it is often required to know what the power > > > costs are from userspace. > > > > > > For this reason, introduce under /sys/kernel/debug/energy_model a set of > > > directories representing the performance domains of the system. Each > > > performance domain contains a set of sub-directories representing the > > > different capacity states (cs) and their attributes, as well as a file > > > exposing the related CPUs. > > > > > > The resulting hierarchy is as follows on Arm juno r0 for example: > > > > > > /sys/kernel/debug/energy_model > > > ├── pd0 > > > │ ├── cpus > > > │ ├── cs:450000 > > > │ │ ├── cost > > > │ │ ├── frequency > > > │ │ └── power > > > │ ├── cs:575000 > > > │ │ ├── cost > > > │ │ ├── frequency > > > │ │ └── power > > > │ ├── cs:700000 > > > │ │ ├── cost > > > │ │ ├── frequency > > > │ │ └── power > > > │ ├── cs:775000 > > > │ │ ├── cost > > > │ │ ├── frequency > > > │ │ └── power > > > │ └── cs:850000 > > > │ ├── cost > > > │ ├── frequency > > > │ └── power > > > └── pd1 > > > ├── cpus > > > ├── cs:1100000 > > > │ ├── cost > > > │ ├── frequency > > > │ └── power > > > ├── cs:450000 > > > │ ├── cost > > > │ ├── frequency > > > │ └── power > > > ├── cs:625000 > > > │ ├── cost > > > │ ├── frequency > > > │ └── power > > > ├── cs:800000 > > > │ ├── cost > > > │ ├── frequency > > > │ └── power > > > └── cs:950000 > > > ├── cost > > > ├── frequency > > > └── power > > > > > > Signed-off-by: Quentin Perret <quentin.perret@arm.com> > > > > > > --- > > > > > > V2: removed check on return value of debugfs_create_* (Greg KH) > > > --- > > > kernel/power/energy_model.c | 57 +++++++++++++++++++++++++++++++++++++ > > > 1 file changed, 57 insertions(+) > > > > Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Applied, thanks!
diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c index d9dc2c38764a..7d66ee68aaaf 100644 --- a/kernel/power/energy_model.c +++ b/kernel/power/energy_model.c @@ -10,6 +10,7 @@ #include <linux/cpu.h> #include <linux/cpumask.h> +#include <linux/debugfs.h> #include <linux/energy_model.h> #include <linux/sched/topology.h> #include <linux/slab.h> @@ -23,6 +24,60 @@ static DEFINE_PER_CPU(struct em_perf_domain *, em_data); */ static DEFINE_MUTEX(em_pd_mutex); +#ifdef CONFIG_DEBUG_FS +static struct dentry *rootdir; + +static void em_debug_create_cs(struct em_cap_state *cs, struct dentry *pd) +{ + struct dentry *d; + char name[24]; + + snprintf(name, sizeof(name), "cs:%lu", cs->frequency); + + /* Create per-cs directory */ + d = debugfs_create_dir(name, pd); + debugfs_create_ulong("frequency", 0444, d, &cs->frequency); + debugfs_create_ulong("power", 0444, d, &cs->power); + debugfs_create_ulong("cost", 0444, d, &cs->cost); +} + +static int em_debug_cpus_show(struct seq_file *s, void *unused) +{ + seq_printf(s, "%*pbl\n", cpumask_pr_args(to_cpumask(s->private))); + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(em_debug_cpus); + +static void em_debug_create_pd(struct em_perf_domain *pd, int cpu) +{ + struct dentry *d; + char name[8]; + int i; + + snprintf(name, sizeof(name), "pd%d", cpu); + + /* Create the directory of the performance domain */ + d = debugfs_create_dir(name, rootdir); + + debugfs_create_file("cpus", 0444, d, pd->cpus, &em_debug_cpus_fops); + + /* Create a sub-directory for each capacity state */ + for (i = 0; i < pd->nr_cap_states; i++) + em_debug_create_cs(&pd->table[i], d); +} + +static int __init em_debug_init(void) +{ + /* Create /sys/kernel/debug/energy_model directory */ + rootdir = debugfs_create_dir("energy_model", NULL); + + return 0; +} +core_initcall(em_debug_init); +#else /* CONFIG_DEBUG_FS */ +static void em_debug_create_pd(struct em_perf_domain *pd, int cpu) {} +#endif static struct em_perf_domain *em_create_pd(cpumask_t *span, int nr_states, struct em_data_callback *cb) { @@ -102,6 +157,8 @@ static struct em_perf_domain *em_create_pd(cpumask_t *span, int nr_states, pd->nr_cap_states = nr_states; cpumask_copy(to_cpumask(pd->cpus), span); + em_debug_create_pd(pd, cpu); + return pd; free_cs_table:
The recently introduced Energy Model (EM) framework manages power cost tables of CPUs. These tables are currently only visible from kernel space. However, in order to debug the behaviour of subsystems that use the EM (EAS for example), it is often required to know what the power costs are from userspace. For this reason, introduce under /sys/kernel/debug/energy_model a set of directories representing the performance domains of the system. Each performance domain contains a set of sub-directories representing the different capacity states (cs) and their attributes, as well as a file exposing the related CPUs. The resulting hierarchy is as follows on Arm juno r0 for example: /sys/kernel/debug/energy_model ├── pd0 │ ├── cpus │ ├── cs:450000 │ │ ├── cost │ │ ├── frequency │ │ └── power │ ├── cs:575000 │ │ ├── cost │ │ ├── frequency │ │ └── power │ ├── cs:700000 │ │ ├── cost │ │ ├── frequency │ │ └── power │ ├── cs:775000 │ │ ├── cost │ │ ├── frequency │ │ └── power │ └── cs:850000 │ ├── cost │ ├── frequency │ └── power └── pd1 ├── cpus ├── cs:1100000 │ ├── cost │ ├── frequency │ └── power ├── cs:450000 │ ├── cost │ ├── frequency │ └── power ├── cs:625000 │ ├── cost │ ├── frequency │ └── power ├── cs:800000 │ ├── cost │ ├── frequency │ └── power └── cs:950000 ├── cost ├── frequency └── power Signed-off-by: Quentin Perret <quentin.perret@arm.com> --- V2: removed check on return value of debugfs_create_* (Greg KH) --- kernel/power/energy_model.c | 57 +++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+)