@@ -259,17 +259,22 @@ 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;
- 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;
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> --- Changes from RFD - discard CFS contribution only as stale (as suggested by Rafael) --- kernel/sched/cpufreq_schedutil.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-)