From 38d4ea229d25d30be6bf41bcd6cd663a587866ca Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 22 Mar 2017 18:32:47 +0100 Subject: [PATCH] cpufreq: schedutil: Trace frequency only if it has changed sugov_update_commit() calls trace_cpu_frequency() to record the current CPU frequency if it has not changed in the fast switch case to prevent utilities from getting confused (they may report that the CPU is idle if the frequency has not been recorded for too long, for example). However, that may cause the tracepoint to be triggered quite often for no real reason (if the frequency doesn't change, we will not modify the last update time stamp and governor computations may run again shortly when that happens), so don't do that (arguably, it is done to work around a utilities bug anyway). That allows code duplication in sugov_update_commit() to be reduced somewhat too. Signed-off-by: Rafael J. Wysocki Acked-by: Viresh Kumar --- kernel/sched/cpufreq_schedutil.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index c1ffb5d..1054f86 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -98,22 +98,20 @@ static void sugov_update_commit(struct sugov_policy *sg_policy, u64 time, { struct cpufreq_policy *policy = sg_policy->policy; + if (sg_policy->next_freq == next_freq) + return; + + sg_policy->next_freq = next_freq; + sg_policy->last_freq_update_time = time; + if (policy->fast_switch_enabled) { - if (sg_policy->next_freq == next_freq) { - trace_cpu_frequency(policy->cur, smp_processor_id()); - return; - } - sg_policy->next_freq = next_freq; - sg_policy->last_freq_update_time = time; next_freq = cpufreq_driver_fast_switch(policy, next_freq); if (next_freq == CPUFREQ_ENTRY_INVALID) return; policy->cur = next_freq; trace_cpu_frequency(next_freq, smp_processor_id()); - } else if (sg_policy->next_freq != next_freq) { - sg_policy->next_freq = next_freq; - sg_policy->last_freq_update_time = time; + } else { sg_policy->work_in_progress = true; irq_work_queue(&sg_policy->irq_work); } -- 2.7.4