>From ae6eb75162f11674cbdc569466e3def4e0eed077 Mon Sep 17 00:00:00 2001 From: Steve Muckle Date: Tue, 12 Apr 2016 15:19:34 -0700 Subject: [PATCH 2/2] sched/fair: call cpufreq hook for remote wakeups Without calling the cpufreq hook for a remote wakeup it is possible for such a wakeup to go unnoticed by cpufreq on the target CPU for up to a full tick. Signed-off-by: Steve Muckle --- kernel/sched/fair.c | 8 +++----- kernel/sched/sched.h | 7 ++++--- 2 files changed, 7 insertions(+), 8 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index b06c1e938cb9..d21a80a44b6e 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2826,15 +2826,13 @@ static inline void cfs_rq_util_change(struct cfs_rq *cfs_rq) struct rq *rq = rq_of(cfs_rq); int cpu = cpu_of(rq); - if (cpu == smp_processor_id() && &rq->cfs == cfs_rq) { + if (&rq->cfs == cfs_rq) { unsigned long max = rq->cpu_capacity_orig; /* * There are a few boundary cases this might miss but it should * get called often enough that that should (hopefully) not be - * a real problem -- added to that it only calls on the local - * CPU, so if we enqueue remotely we'll miss an update, but - * the next tick/schedule should update. + * a real problem. * * It will not get called when we go idle, because the idle * thread is a different class (!fair), nor will the utilization @@ -2845,7 +2843,7 @@ static inline void cfs_rq_util_change(struct cfs_rq *cfs_rq) * * See cpu_util(). */ - cpufreq_update_util(rq_clock(rq), + cpufreq_update_util(cpu, rq_clock(rq), min(cfs_rq->avg.util_avg, max), max); } } diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 921d6e5d33b7..01faa0781099 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1808,11 +1808,12 @@ DECLARE_PER_CPU(struct update_util_data *, cpufreq_update_util_data); * * It can only be called from RCU-sched read-side critical sections. */ -static inline void cpufreq_update_util(u64 time, unsigned long util, unsigned long max) +static inline void cpufreq_update_util(int cpu, u64 time, unsigned long util, + unsigned long max) { struct update_util_data *data; - data = rcu_dereference_sched(*this_cpu_ptr(&cpufreq_update_util_data)); + data = rcu_dereference_sched(per_cpu(cpufreq_update_util_data, cpu)); if (data) data->func(data, time, util, max); } @@ -1835,7 +1836,7 @@ static inline void cpufreq_update_util(u64 time, unsigned long util, unsigned lo */ static inline void cpufreq_trigger_update(u64 time) { - cpufreq_update_util(time, ULONG_MAX, 0); + cpufreq_update_util(smp_processor_id(), time, ULONG_MAX, 0); } #else static inline void cpufreq_update_util(u64 time, unsigned long util, unsigned long max) {} -- 2.4.10