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authorDietmar Eggemann <dietmar.eggemann@arm.com>2015-09-07 14:57:22 +0100
committerIngo Molnar <mingo@kernel.org>2015-09-13 09:53:01 +0200
commit6f2b04524f0b38bfbb8413f98d2d6af234508309 (patch)
tree9801d81b972f0993fdd2fdbe05e03dca4a27943c /kernel
parent6115c793ca1a6e39c7c15159cbb47baa04009cb8 (diff)
downloadop-kernel-dev-6f2b04524f0b38bfbb8413f98d2d6af234508309.zip
op-kernel-dev-6f2b04524f0b38bfbb8413f98d2d6af234508309.tar.gz
sched/fair: Defer calling scaling functions
Do not call the scaling functions in case time goes backwards or the last update of the sched_avg structure has happened less than 1024ns ago. Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Juri Lelli <Juri.Lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: daniel.lezcano@linaro.org <daniel.lezcano@linaro.org> Cc: mturquette@baylibre.com <mturquette@baylibre.com> Cc: pang.xunlei@zte.com.cn <pang.xunlei@zte.com.cn> Cc: rjw@rjwysocki.net <rjw@rjwysocki.net> Cc: sgurrappadi@nvidia.com <sgurrappadi@nvidia.com> Cc: vincent.guittot@linaro.org <vincent.guittot@linaro.org> Cc: yuyang.du@intel.com <yuyang.du@intel.com> Link: http://lkml.kernel.org/r/55EDA2E9.8040900@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/sched/fair.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index c3c5585..fc835fa 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2552,8 +2552,7 @@ __update_load_avg(u64 now, int cpu, struct sched_avg *sa,
u64 delta, scaled_delta, periods;
u32 contrib;
unsigned int delta_w, scaled_delta_w, decayed = 0;
- unsigned long scale_freq = arch_scale_freq_capacity(NULL, cpu);
- unsigned long scale_cpu = arch_scale_cpu_capacity(NULL, cpu);
+ unsigned long scale_freq, scale_cpu;
delta = now - sa->last_update_time;
/*
@@ -2574,6 +2573,9 @@ __update_load_avg(u64 now, int cpu, struct sched_avg *sa,
return 0;
sa->last_update_time = now;
+ scale_freq = arch_scale_freq_capacity(NULL, cpu);
+ scale_cpu = arch_scale_cpu_capacity(NULL, cpu);
+
/* delta_w is the amount already accumulated against our next period */
delta_w = sa->period_contrib;
if (delta + delta_w >= 1024) {
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