Commit-ID: 6f2b04524f0b38bfbb8413f98d2d6af234508309 Gitweb: http://git.kernel.org/tip/6f2b04524f0b38bfbb8413f98d2d6af234508309 Author: Dietmar Eggemann <dietmar.eggem...@arm.com> AuthorDate: Mon, 7 Sep 2015 14:57:22 +0100 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Sun, 13 Sep 2015 09:53:01 +0200
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.eggem...@arm.com> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Cc: Juri Lelli <juri.le...@arm.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Mike Galbraith <efa...@gmx.de> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: daniel.lezc...@linaro.org <daniel.lezc...@linaro.org> Cc: mturque...@baylibre.com <mturque...@baylibre.com> Cc: pang.xun...@zte.com.cn <pang.xun...@zte.com.cn> Cc: r...@rjwysocki.net <r...@rjwysocki.net> Cc: sgurrapp...@nvidia.com <sgurrapp...@nvidia.com> Cc: vincent.guit...@linaro.org <vincent.guit...@linaro.org> Cc: yuyang...@intel.com <yuyang...@intel.com> Link: http://lkml.kernel.org/r/55eda2e9.8040...@arm.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- kernel/sched/fair.c | 6 ++++-- 1 file 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) { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
