On 13-11-25, 19:41, Samuel Wu wrote: > On Wed, Nov 12, 2025 at 10:45 PM Viresh Kumar <[email protected]> wrote: > > > > On 12-11-25, 15:51, Samuel Wu wrote: > > > The existing cpu_frequency trace_event can be verbose, emitting an event > > > for every CPU in the policy even when their frequencies are identical. > > > > > > This patch adds a new policy_frequency trace event, which provides a > > > more efficient alternative to cpu_frequency trace event. This option > > > allows users who only need frequency at a policy level more concise logs > > > with simpler analysis. > > > > > > Signed-off-by: Samuel Wu <[email protected]> > > > --- > > > drivers/cpufreq/cpufreq.c | 2 ++ > > > include/trace/events/power.h | 21 +++++++++++++++++++++ > > > 2 files changed, 23 insertions(+) > > > > > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > > > index 4472bb1ec83c..b65534a4fd9a 100644 > > > --- a/drivers/cpufreq/cpufreq.c > > > +++ b/drivers/cpufreq/cpufreq.c > > > @@ -345,6 +345,7 @@ static void cpufreq_notify_transition(struct > > > cpufreq_policy *policy, > > > pr_debug("FREQ: %u - CPUs: %*pbl\n", freqs->new, > > > cpumask_pr_args(policy->cpus)); > > > > > > + trace_policy_frequency(freqs->new, policy->cpu); > > > for_each_cpu(cpu, policy->cpus) > > > trace_cpu_frequency(freqs->new, cpu); > > > > I don't see much value in almost duplicate trace events. If we feel that a > > per-policy event is a better fit (which makes sens), then we can just drop > > the > > trace_cpu_frequency() events and print policy->cpus (or related_cpus) > > information along with the per-policy events. > > Thank you for the feedback Viresh. Fair enough, I've done some testing > and a single trace event should work and would be cleaner. Please let > me know what you think of this proposal for v2. > > We can append a bitmask of policy->cpus field to > trace_cpu_frequency(). This way we maintain backwards compatibility: > trace_cpu_frequency() is not removed, and its pre-existing fields are > not disturbed. > > Call flow wise, we can delete all the for_each_cpu() loops, and we > still retain the benefits of the trace emitting once per policy > instead of once per cpu.
Fine by me. I have added Scheduler maintainers in the loop to see if they have a different view. -- viresh
