On Fri, 3 Mar 2017 09:11:25 +0530 Viresh Kumar <viresh.ku...@linaro.org> wrote:
> On 02-03-17, 15:45, Patrick Bellasi wrote: > > diff --git a/include/linux/sched.h b/include/linux/sched.h > > index e2ed46d..739b29d 100644 > > --- a/include/linux/sched.h > > +++ b/include/linux/sched.h > > @@ -3653,6 +3653,7 @@ static inline unsigned long rlimit_max(unsigned int > > limit) > > #define SCHED_CPUFREQ_RT (1U << 0) > > #define SCHED_CPUFREQ_DL (1U << 1) > > #define SCHED_CPUFREQ_IOWAIT (1U << 2) > > +#define SCHED_CPUFREQ_IDLE (1U << 3) > > > > #define SCHED_CPUFREQ_RT_DL (SCHED_CPUFREQ_RT | SCHED_CPUFREQ_DL) > > > > diff --git a/kernel/sched/cpufreq_schedutil.c > > b/kernel/sched/cpufreq_schedutil.c > > index fd46593..084a98b 100644 > > --- a/kernel/sched/cpufreq_schedutil.c > > +++ b/kernel/sched/cpufreq_schedutil.c > > @@ -281,6 +281,12 @@ static void sugov_update_shared(struct > > update_util_data *hook, u64 time, > > > > raw_spin_lock(&sg_policy->update_lock); > > > > + /* CPU is entering IDLE, reset flags without triggering an update */ > > + if (flags & SCHED_CPUFREQ_IDLE) { > > Will "flags == SCHED_CPUFREQ_IDLE" generate better assembly ? > Even if it does, a bit check and an equal check are pretty negligible in difference wrt execution time. I would choose whatever is the most readable to humans. flags == SCHED_CPUFREQ_IDLE will tell me (as a reviewer) that we expect no other flag to be set. flags & SCHED_CPUFREQ_IDLE will tell me that we only care about the IDLE flag. Which ever is the more meaningful is what should be used. -- Steve > > + sg_cpu->flags = 0; > > + goto done; > > + } > > + > > sg_cpu->util = util; > > sg_cpu->max = max; > > sg_cpu->flags = flags; > > @@ -293,6 +299,7 @@ static void sugov_update_shared(struct update_util_data > > *hook, u64 time, > > sugov_update_commit(sg_policy, time, next_f); > > } > > > > +done: > > raw_spin_unlock(&sg_policy->update_lock); > > } > > > > diff --git a/kernel/sched/idle_task.c b/kernel/sched/idle_task.c > > index 0c00172..a844c91 100644 > > --- a/kernel/sched/idle_task.c > > +++ b/kernel/sched/idle_task.c > > @@ -29,6 +29,10 @@ pick_next_task_idle(struct rq *rq, struct task_struct > > *prev, struct rq_flags *rf > > put_prev_task(rq, prev); > > update_idle_core(rq); > > schedstat_inc(rq->sched_goidle); > > + > > + /* kick cpufreq (see the comment in kernel/sched/sched.h). */ > > + cpufreq_update_this_cpu(rq, SCHED_CPUFREQ_IDLE); > > + > > return rq->idle; > > } > > > > -- > > 2.7.4 >