[RFD PATCH 4/5] sched/cpufreq_schedutil: always consider all CPUs when deciding next freq

[Juri Lelli]

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.

Signed-off-by: Juri Lelli <juri.lelli@xxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Cc: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
Cc: Luca Abeni <luca.abeni@xxxxxxxxxxxxxxx>
Cc: Claudio Scordino <claudio@xxxxxxxxxxxxxxx>
---
 kernel/sched/cpufreq_schedutil.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
index da67a1cf91e7..40f30373b709 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -233,14 +233,13 @@ static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu)
 		 * 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).
+		 * enough, reset iowait_boost, as it probably is not boosted
+		 * anymore now.
 		 */
 		delta_ns = last_freq_update_time - j_sg_cpu->last_update;
-		if (delta_ns > TICK_NSEC) {
+		if (delta_ns > TICK_NSEC)
 			j_sg_cpu->iowait_boost = 0;
-			continue;
-		}
+
 		if (j_sg_cpu->flags & SCHED_CPUFREQ_RT)
 			return policy->cpuinfo.max_freq;
 
-- 
2.10.0