Messages in this thread Patch in this message | | | From | Juri Lelli <> | Subject | [RFC PATCH v2 5/8] sched/cpufreq_schedutil: always consider all CPUs when deciding next freq | Date | Mon, 4 Dec 2017 11:23:22 +0100 |
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From: Juri Lelli <juri.lelli@arm.com>
No assumption can be made upon the rate at which frequency updates get triggered, as there are scheduling policies (like SCHED_DEADLINE) which don't trigger them so frequently.
Remove such assumption from the code, by always considering SCHED_DEADLINE utilization signal as not stale.
Signed-off-by: Juri Lelli <juri.lelli@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Luca Abeni <luca.abeni@santannapisa.it> Cc: Claudio Scordino <claudio@evidence.eu.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> --- kernel/sched/cpufreq_schedutil.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index a3072f24dc16..b7a576c8dcaa 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -318,17 +318,21 @@ static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, u64 time) s64 delta_ns; /* - * If the CPU utilization was last updated before the previous - * frequency update and the time elapsed between the last update - * of the CPU utilization and the last frequency update is long - * enough, don't take the CPU into account as it probably is - * idle now (and clear iowait_boost for it). + * If the CFS CPU utilization was last updated before the + * previous frequency update and the time elapsed between the + * last update of the CPU utilization and the last frequency + * update is long enough, reset iowait_boost and util_cfs, as + * they are now probably stale. However, still consider the + * CPU contribution if it has some DEADLINE utilization + * (util_dl). */ delta_ns = time - j_sg_cpu->last_update; if (delta_ns > TICK_NSEC) { j_sg_cpu->iowait_boost = 0; j_sg_cpu->iowait_boost_pending = false; - continue; + j_sg_cpu->util_cfs = 0; + if (j_sg_cpu->util_dl == 0) + continue; } if (j_sg_cpu->flags & SCHED_CPUFREQ_RT) return policy->cpuinfo.max_freq; -- 2.14.3
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