From 466a2b42d67644447a1765276259a3ea5531ddff Mon Sep 17 00:00:00 2001 From: Joel Fernandes Date: Thu, 21 Dec 2017 02:22:45 +0100 Subject: cpufreq: schedutil: Use idle_calls counter of the remote CPU Since the recent remote cpufreq callback work, its possible that a cpufreq update is triggered from a remote CPU. For single policies however, the current code uses the local CPU when trying to determine if the remote sg_cpu entered idle or is busy. This is incorrect. To remedy this, compare with the nohz tick idle_calls counter of the remote CPU. Fixes: 674e75411fc2 (sched: cpufreq: Allow remote cpufreq callbacks) Acked-by: Viresh Kumar Acked-by: Peter Zijlstra (Intel) Signed-off-by: Joel Fernandes Cc: 4.14+ # 4.14+ Signed-off-by: Rafael J. Wysocki --- kernel/time/tick-sched.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'kernel/time/tick-sched.c') diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 99578f06c8d4..77555faf6fbc 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -985,6 +985,19 @@ ktime_t tick_nohz_get_sleep_length(void) return ts->sleep_length; } +/** + * tick_nohz_get_idle_calls_cpu - return the current idle calls counter value + * for a particular CPU. + * + * Called from the schedutil frequency scaling governor in scheduler context. + */ +unsigned long tick_nohz_get_idle_calls_cpu(int cpu) +{ + struct tick_sched *ts = tick_get_tick_sched(cpu); + + return ts->idle_calls; +} + /** * tick_nohz_get_idle_calls - return the current idle calls counter value * -- cgit v1.2.3