On Thursday, March 09, 2017 05:15:15 PM Viresh Kumar wrote: > From: Steve Muckle <[email protected]> > > Upcoming support for remote callbacks from the scheduler into schedutil > requires that the CPU identified in the hook structure be used to > indicate the CPU being operated on, rather than relying on > smp_processor_id(). > > Note that policy->cpu is passed to trace_cpu_frequency() in fast switch > path, as it is safe to use any CPU which is managed by the current > policy.
This should be commented about in the code too IMO. > > Signed-off-by: Steve Muckle <[email protected]> > [ vk: updated commit log, minor code cleanups and use policy->cpu for > traces ] > Signed-off-by: Viresh Kumar <[email protected]> > --- > kernel/sched/cpufreq_schedutil.c | 14 +++++++------- > 1 file changed, 7 insertions(+), 7 deletions(-) > > diff --git a/kernel/sched/cpufreq_schedutil.c > b/kernel/sched/cpufreq_schedutil.c > index a418544c51b1..b168c31f1c8f 100644 > --- a/kernel/sched/cpufreq_schedutil.c > +++ b/kernel/sched/cpufreq_schedutil.c > @@ -96,7 +96,7 @@ static void sugov_fast_switch(struct cpufreq_policy *policy, > return; > > policy->cur = next_freq; > - trace_cpu_frequency(next_freq, smp_processor_id()); > + trace_cpu_frequency(next_freq, policy->cpu); > } > > static void sugov_update_commit(struct sugov_policy *sg_policy, u64 time, > @@ -106,7 +106,7 @@ static void sugov_update_commit(struct sugov_policy > *sg_policy, u64 time, > > if (policy->fast_switch_enabled) { > if (sg_policy->next_freq == next_freq) { > - trace_cpu_frequency(policy->cur, smp_processor_id()); > + trace_cpu_frequency(policy->cur, policy->cpu); > return; > } > sg_policy->next_freq = next_freq; > @@ -157,12 +157,12 @@ static unsigned int get_next_freq(struct sugov_policy > *sg_policy, > return cpufreq_driver_resolve_freq(policy, freq); > } > > -static void sugov_get_util(unsigned long *util, unsigned long *max) > +static void sugov_get_util(unsigned long *util, unsigned long *max, int cpu) > { > - struct rq *rq = this_rq(); > + struct rq *rq = cpu_rq(cpu); > unsigned long cfs_max; > > - cfs_max = arch_scale_cpu_capacity(NULL, smp_processor_id()); > + cfs_max = arch_scale_cpu_capacity(NULL, cpu); > > *util = min(rq->cfs.avg.util_avg, cfs_max); > *max = cfs_max; > @@ -216,7 +216,7 @@ static void sugov_update_single(struct update_util_data > *hook, u64 time, > if (flags & SCHED_CPUFREQ_RT_DL) { > next_f = policy->cpuinfo.max_freq; > } else { > - sugov_get_util(&util, &max); > + sugov_get_util(&util, &max, hook->cpu); Why is this not racy? > sugov_iowait_boost(sg_cpu, &util, &max); > next_f = get_next_freq(sg_policy, util, max); > } > @@ -272,7 +272,7 @@ static void sugov_update_shared(struct update_util_data > *hook, u64 time, > unsigned long util, max; > unsigned int next_f; > > - sugov_get_util(&util, &max); > + sugov_get_util(&util, &max, hook->cpu); > And here? > raw_spin_lock(&sg_policy->update_lock); > > Thanks, Rafael
