| Message ID | 20171130114723.29210-4-patrick.bellasi@arm.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v3,1/6] cpufreq: schedutil: reset sg_cpus's flags at IDLE enter | expand |
Hi, On 30/11/17 11:47, Patrick Bellasi wrote: > Currently the utilization of the FAIR class is collected before locking > the policy. Although that should not be a big issue for most cases, we > also don't really know how much latency there can be between the > utilization reading and its usage. > > Let's get the FAIR utilization right before its usage to be better in > sync with the current status of a CPU. > > Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com> > Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > Cc: Viresh Kumar <viresh.kumar@linaro.org> > Cc: linux-kernel@vger.kernel.org > Cc: linux-pm@vger.kernel.org > > --- > Changes from v2: > - rebased on v4.15-rc1 > > Change-Id: I9291a560bcad7db76894e3f0fcdb917511d0479e > --- > kernel/sched/cpufreq_schedutil.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c > index 448f49de5335..40521d59630b 100644 > --- a/kernel/sched/cpufreq_schedutil.c > +++ b/kernel/sched/cpufreq_schedutil.c > @@ -351,10 +351,9 @@ static void sugov_update_shared(struct update_util_data *hook, u64 time, > unsigned int next_f; > bool rt_mode; > > - sugov_get_util(&util, &max, sg_cpu->cpu); > - > raw_spin_lock(&sg_policy->update_lock); > > + sugov_get_util(&util, &max, sg_cpu->cpu); > sg_cpu->util = util; > sg_cpu->max = max; Patch looks good. Reviewed-by: Juri Lelli <juri.lelli@redhat.com> However, not sure $SUBJECT is really in sync with what the patch does? CFS gets "used" before and after the patch... last paragraph of the changelog looks more like it. :) Best, Juri
On 07-Dec 10:45, Viresh Kumar wrote: > On 30-11-17, 15:57, Patrick Bellasi wrote: > > Yes, that's a pretty trivial update with a confusing changelog. > > > > If we think it's worth to keep (and correct as well) I'll update the > > commit message. > > We also need to update the commit log based on feedback from Vikram on > V2. Which said that the utilization can't change around the lock here > as we are within rq lock section, though max can change (maybe). So > this patch only takes care of locking before reading max. Ok, right... will do. Thus you are still of the opinion to keep this patch in the series? -- #include <best/regards.h> Patrick Bellasi
diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 448f49de5335..40521d59630b 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -351,10 +351,9 @@ static void sugov_update_shared(struct update_util_data *hook, u64 time, unsigned int next_f; bool rt_mode; - sugov_get_util(&util, &max, sg_cpu->cpu); - raw_spin_lock(&sg_policy->update_lock); + sugov_get_util(&util, &max, sg_cpu->cpu); sg_cpu->util = util; sg_cpu->max = max;