sched/cpufreq: Align trace event behavior of fast switching

BugLink: https://bugs.launchpad.net/bugs/1848046
[ Upstream commit 77c84dd1881d0f0176cb678d770bfbda26c54390 ]

Fast switching path only emits an event for the CPU of interest, whereas the
regular path emits an event for all the CPUs that had their frequency changed,
i.e. all the CPUs sharing the same policy.

With the current behavior, looking at cpu_frequency event for a given CPU that
is using the fast switching path will not give the correct frequency signal.

Signed-off-by: Douglas RAILLARD <douglas.raillard@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
index 867b4bb6d4beb541d1d9eb087711d1e52a446416..b03ca2f73713dfb516f5644bbd62d59151d6cd15 100644 (file)
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -117,6 +117,7 @@ static void sugov_fast_switch(struct sugov_policy *sg_policy, u64 time,
                              unsigned int next_freq)
 {
        struct cpufreq_policy *policy = sg_policy->policy;
+       int cpu;
 
        if (!sugov_update_next_freq(sg_policy, time, next_freq))
                return;
@@ -126,7 +127,11 @@ static void sugov_fast_switch(struct sugov_policy *sg_policy, u64 time,
                return;
 
        policy->cur = next_freq;
-       trace_cpu_frequency(next_freq, smp_processor_id());
+
+       if (trace_cpu_frequency_enabled()) {
+               for_each_cpu(cpu, policy->cpus)
+                       trace_cpu_frequency(next_freq, cpu);
+       }
 }
 
 static void sugov_deferred_update(struct sugov_policy *sg_policy, u64 time,