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. This can occur if the target CPU is running a CPU-bound task.
Signed-off-by: Steve Muckle <[email protected]> --- kernel/sched/fair.c | 8 +++----- kernel/sched/sched.h | 17 ++++++++++------- 2 files changed, 13 insertions(+), 12 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..a8a1eb603263 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1799,6 +1799,7 @@ DECLARE_PER_CPU(struct update_util_data *, cpufreq_update_util_data); /** * cpufreq_update_util - Take a note about CPU utilization changes. + * @cpu: Target CPU. * @time: Current time. * @util: Current utilization. * @max: Utilization ceiling. @@ -1808,13 +1809,14 @@ 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; + struct update_util_data *data; - data = rcu_dereference_sched(*this_cpu_ptr(&cpufreq_update_util_data)); - if (data) - data->func(data, time, util, max); + data = rcu_dereference_sched(per_cpu(cpufreq_update_util_data, cpu)); + if (data) + data->func(data, time, util, max); } /** @@ -1835,10 +1837,11 @@ 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) {} +static inline void cpufreq_update_util(int cpu, u64 time, unsigned long util, + unsigned long max) {} static inline void cpufreq_trigger_update(u64 time) {} #endif /* CONFIG_CPU_FREQ */ -- 2.4.10
