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| 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 /init | |
| 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 'init')
| -rw-r--r-- | init/Kconfig | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/init/Kconfig b/init/Kconfig index e1d1d6936f92..ee1dd90254b7 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1237,6 +1237,32 @@ config SCHED_AUTOGROUP desktop applications. Task group autogeneration is currently based upon task session. +config SCHED_TUNE + bool "Boosting for CFS tasks (EXPERIMENTAL)" + help + This option enables the system-wide support for task boosting. + When this support is enabled a new sysctl interface is exposed to + userspace via: + /proc/sys/kernel/sched_cfs_boost + which allows to set a system-wide boost value in range [0..100]. + + The currently boosting strategy is implemented in such a way that: + - a 0% boost value requires to operate in "standard" mode by + scheduling all tasks at the minimum capacities required by their + workload demand + - a 100% boost value 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. + + Since this support exposes a single system-wide knob, the specified + boost value is applied to all (CFS) tasks in the system. + + If unsure, say N. + config SYSFS_DEPRECATED bool "Enable deprecated sysfs features to support old userspace tools" depends on SYSFS |