| Message ID | 20190515135322.19393-3-parth@linux.ibm.com (mailing list archive) |
|---|---|
| State | RFC, archived |
| Headers | show |
| Series | TurboSched: A scheduler for sustaining Turbo Frequencies for longer durations | expand |
On Wed, May 15, 2019 at 07:23:18PM +0530, Parth Shah wrote: > +void turbo_sched_get(void) > +{ > + spin_lock(&turbo_sched_lock); > + if (!turbo_sched_count++) > + static_branch_enable(&__turbo_sched_enabled); > + spin_unlock(&turbo_sched_lock); > +} Muwhahaha, you didn't test this code, did you?
On 5/15/19 10:00 PM, Peter Zijlstra wrote: > On Wed, May 15, 2019 at 07:23:18PM +0530, Parth Shah wrote: >> +void turbo_sched_get(void) >> +{ >> + spin_lock(&turbo_sched_lock); >> + if (!turbo_sched_count++) >> + static_branch_enable(&__turbo_sched_enabled); >> + spin_unlock(&turbo_sched_lock); >> +} > > Muwhahaha, you didn't test this code, did you? > yeah, I didn't see task-sleep problem coming in. I will change to mutex. Thanks for pointing out.
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 77aa4aee4478..facbedd2554e 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -60,6 +60,26 @@ __read_mostly int scheduler_running; */ int sysctl_sched_rt_runtime = 950000; +DEFINE_STATIC_KEY_FALSE(__turbo_sched_enabled); +static DEFINE_SPINLOCK(turbo_sched_lock); +static int turbo_sched_count; + +void turbo_sched_get(void) +{ + spin_lock(&turbo_sched_lock); + if (!turbo_sched_count++) + static_branch_enable(&__turbo_sched_enabled); + spin_unlock(&turbo_sched_lock); +} + +void turbo_sched_put(void) +{ + spin_lock(&turbo_sched_lock); + if (!--turbo_sched_count) + static_branch_disable(&__turbo_sched_enabled); + spin_unlock(&turbo_sched_lock); +} + /* * __task_rq_lock - lock the rq @p resides on. */ diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index e75ffaf3ff34..0339964cdf43 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -2437,3 +2437,10 @@ static inline bool sched_energy_enabled(void) static inline bool sched_energy_enabled(void) { return false; } #endif /* CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL */ + +DECLARE_STATIC_KEY_FALSE(__turbo_sched_enabled); + +static inline bool is_turbosched_enabled(void) +{ + return static_branch_unlikely(&__turbo_sched_enabled); +}
This patch creates a static key which allows to enable or disable TurboSched feature at runtime. This key is added in order to enable the TurboSched feature. The static key helps in optimizing the scheduler fast-path when the TurboSched feature is disabled. The patch also provides get/put methods to keep track of the cgroups using the TurboSched feature. This allows to enable the feature on adding first cgroup classified as jitter, similarly disable the feature on removal of such last cgroup. Signed-off-by: Parth Shah <parth@linux.ibm.com> --- kernel/sched/core.c | 20 ++++++++++++++++++++ kernel/sched/sched.h | 7 +++++++ 2 files changed, 27 insertions(+)