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| author | Vincent Guittot <vincent.guittot@linaro.org> | 2019-01-23 18:26:54 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2019-02-04 11:13:21 +0300 |
| commit | 10a35e6812aa0953f02a956c499d23fe4e68af4a (patch) | |
| tree | 11c866b0777d735f814a0886e91eb0139f7cc4e4 /kernel/sched/sched.h | |
| parent | 23127296889fe84b0762b191b5d041e8ba6f2599 (diff) | |
| download | linux-10a35e6812aa0953f02a956c499d23fe4e68af4a.tar.xz | |
sched/pelt: Skip updating util_est when utilization is higher than CPU's capacity
util_est is mainly meant to be a lower-bound for tasks utilization.
That's why task_util_est() returns the actual util_avg when it's higher
than the estimated utilization.
With new invaraince signal and without any special check on samples
collection, if a task is limited because of thermal capping for
example, we could end up overestimating its utilization and thus
perhaps generating an unwanted frequency spike when the capping is
relaxed... and (even worst) it will take some more activations for the
estimated utilization to converge back to the actual utilization.
Since we cannot easily know if there is idle time in a CPU when a task
completes an activation with a utilization higher then the CPU capacity,
we skip the sampling when utilization is higher than CPU's capacity.
Suggested-by: Patrick Bellasi <patrick.bellasi@arm.com>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Morten.Rasmussen@arm.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bsegall@google.com
Cc: dietmar.eggemann@arm.com
Cc: pjt@google.com
Cc: pkondeti@codeaurora.org
Cc: quentin.perret@arm.com
Cc: rjw@rjwysocki.net
Cc: srinivas.pandruvada@linux.intel.com
Cc: thara.gopinath@linaro.org
Link: https://lkml.kernel.org/r/1548257214-13745-4-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched/sched.h')
| -rw-r--r-- | kernel/sched/sched.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index fe31bc472f3e..99e2a7772d16 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -2230,6 +2230,13 @@ static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {} # define arch_scale_freq_invariant() false #endif +#ifdef CONFIG_SMP +static inline unsigned long capacity_orig_of(int cpu) +{ + return cpu_rq(cpu)->cpu_capacity_orig; +} +#endif + #ifdef CONFIG_CPU_FREQ_GOV_SCHEDUTIL /** * enum schedutil_type - CPU utilization type |