Messages in this thread Patch in this message | | | From | Namhyung Kim <> | Subject | Re: [PATCH 20/24] nohz: Full dynticks mode | Date | Wed, 26 Dec 2012 16:02:18 +0900 |
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On Wed, 26 Dec 2012 15:12:22 +0900, Namhyung Kim wrote: > Hi Frederic, > > On Thu, 20 Dec 2012 19:33:07 +0100, Frederic Weisbecker wrote: >> When a CPU is in full dynticks mode, try to switch >> it to nohz mode from the interrupt exit path if it is >> running a single non-idle task. >> >> Then restart the tick if necessary if we are enqueuing a >> second task while the timer is stopped, so that the scheduler >> tick is rearmed. >> >> [TODO: Check remaining things to be done from scheduler_tick()] >> >> [ Included build fix from Geoff Levand ] > [snip] >> diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h >> index db3d4df..f3d8f4a 100644 >> --- a/kernel/sched/sched.h >> +++ b/kernel/sched/sched.h >> @@ -943,6 +943,14 @@ static inline u64 steal_ticks(u64 steal) >> static inline void inc_nr_running(struct rq *rq) >> { >> rq->nr_running++; >> + >> + if (rq->nr_running == 2) { >> + if (tick_nohz_full_cpu(rq->cpu)) { >> + /* Order rq->nr_running write against the IPI */ >> + smp_wmb(); >> + smp_send_reschedule(rq->cpu); >> + } >> + } > > This block should be guarded with #ifdef CONFIG_SMP, otherwise:
Or apply something like this:
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 0cd913ed29de..8de13ca88a17 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -957,10 +957,10 @@ static inline void inc_nr_running(struct rq *rq) rq->nr_running++; if (rq->nr_running == 2) { - if (tick_nohz_full_cpu(rq->cpu)) { + if (tick_nohz_full_cpu(cpu_of(rq))) { /* Order rq->nr_running write against the IPI */ smp_wmb(); - smp_send_reschedule(rq->cpu); + smp_send_reschedule(cpu_of(rq)); } } }
Thanks, Namhyung
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