diff options
| author | Patrick Bellasi <patrick.bellasi@arm.com> | 2015-06-22 18:11:44 +0100 |
|---|---|---|
| committer | Amit Pundir <amit.pundir@linaro.org> | 2016-09-14 14:58:22 +0530 |
| commit | 724d562ae08905854c2940994950b68c2939db78 (patch) | |
| tree | 493ed70c2cfdd02b6cbd02f9b832a7a31b605d21 /kernel | |
| parent | f6201d94b085121184e694d00768a79bb5a13e9d (diff) | |
sched/tune: add sysctl interface to define a boost value
The current (CFS) scheduler implementation does not allow "to boost"
tasks performance by running them at a higher OPP compared to the
minimum required to meet their workload demands.
To support tasks performance boosting the scheduler should provide a
"knob" which allows to tune how much the system is going to be optimised
for energy efficiency vs performance.
This patch is the first of a series which provides a simple interface to
define a tuning knob. One system-wide "boost" tunable is exposed via:
/proc/sys/kernel/sched_cfs_boost
which can be configured in the range [0..100], to define a percentage
where:
- 0% boost requires to operate in "standard" mode by scheduling
tasks at the minimum capacities required by the workload demand
- 100% boost requires to push at maximum the task performances,
"regardless" of the incurred energy consumption
A boost value in between these two boundaries is used to bias the
power/performance trade-off, the higher the boost value the more the
scheduler is biased toward performance boosting instead of energy
efficiency.
cc: Ingo Molnar <mingo@redhat.com>
cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/Makefile | 1 | ||||
| -rw-r--r-- | kernel/sched/tune.c | 16 | ||||
| -rw-r--r-- | kernel/sysctl.c | 11 |
3 files changed, 28 insertions, 0 deletions
diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile index 0eabc9db4c3d..c6a85f813dfd 100644 --- a/kernel/sched/Makefile +++ b/kernel/sched/Makefile @@ -18,5 +18,6 @@ obj-$(CONFIG_SMP) += cpupri.o cpudeadline.o obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o obj-$(CONFIG_SCHEDSTATS) += stats.o obj-$(CONFIG_SCHED_DEBUG) += debug.o +obj-$(CONFIG_SCHED_TUNE) += tune.o obj-$(CONFIG_CGROUP_CPUACCT) += cpuacct.o obj-$(CONFIG_CPU_FREQ_GOV_SCHED) += cpufreq_sched.o diff --git a/kernel/sched/tune.c b/kernel/sched/tune.c new file mode 100644 index 000000000000..a93af9c2f267 --- /dev/null +++ b/kernel/sched/tune.c @@ -0,0 +1,16 @@ +#include "sched.h" + +unsigned int sysctl_sched_cfs_boost __read_mostly; + +int +sysctl_sched_cfs_boost_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, + loff_t *ppos) +{ + int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); + + if (ret || !write) + return ret; + + return 0; +} diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 11783ed47dd3..2cf1f8610ded 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -435,6 +435,17 @@ static struct ctl_table kern_table[] = { .extra1 = &one, }, #endif +#ifdef CONFIG_SCHED_TUNE + { + .procname = "sched_cfs_boost", + .data = &sysctl_sched_cfs_boost, + .maxlen = sizeof(sysctl_sched_cfs_boost), + .mode = 0644, + .proc_handler = &sysctl_sched_cfs_boost_handler, + .extra1 = &zero, + .extra2 = &one_hundred, + }, +#endif #ifdef CONFIG_PROVE_LOCKING { .procname = "prove_locking", |