From 0fdcccfafcffac70b452b3127cc3d981f0117655 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 13 May 2021 01:29:23 +0200 Subject: [PATCH] tick/nohz: Call tick_nohz_task_switch() with interrupts disabled Call tick_nohz_task_switch() slightly earlier after the context switch to benefit from disabled IRQs. This way the function doesn't need to disable them once more. Signed-off-by: Peter Zijlstra Signed-off-by: Frederic Weisbecker Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20210512232924.150322-10-frederic@kernel.org --- kernel/sched/core.c | 2 +- kernel/time/tick-sched.c | 7 +------ 2 files changed, 2 insertions(+), 7 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 78e480f..8f86ac2 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4212,6 +4212,7 @@ static struct rq *finish_task_switch(struct task_struct *prev) vtime_task_switch(prev); perf_event_task_sched_in(prev, current); finish_task(prev); + tick_nohz_task_switch(); finish_lock_switch(rq); finish_arch_post_lock_switch(); kcov_finish_switch(current); @@ -4257,7 +4258,6 @@ static struct rq *finish_task_switch(struct task_struct *prev) put_task_struct_rcu_user(prev); } - tick_nohz_task_switch(); return rq; } diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 197a3bd..6ea619d 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -487,13 +487,10 @@ void tick_nohz_dep_clear_signal(struct signal_struct *sig, enum tick_dep_bits bi */ void __tick_nohz_task_switch(void) { - unsigned long flags; struct tick_sched *ts; - local_irq_save(flags); - if (!tick_nohz_full_cpu(smp_processor_id())) - goto out; + return; ts = this_cpu_ptr(&tick_cpu_sched); @@ -502,8 +499,6 @@ void __tick_nohz_task_switch(void) atomic_read(¤t->signal->tick_dep_mask)) tick_nohz_full_kick(); } -out: - local_irq_restore(flags); } /* Get the boot-time nohz CPU list from the kernel parameters. */ -- 2.7.4