From dfc68f29ae67f2a6e799b44e6a4eb3417dffbfcd Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Wed, 4 Jun 2014 10:31:15 -0700 Subject: sched, trace: Add a tracepoint for IPI-less remote wakeups Remote wakeups of polling CPUs are a valuable performance improvement; add a tracepoint to make it much easier to verify that they're working. Signed-off-by: Andy Lutomirski Signed-off-by: Peter Zijlstra Cc: nicolas.pitre@linaro.org Cc: daniel.lezcano@linaro.org Cc: umgwanakikbuti@gmail.com Cc: David Ahern Cc: Frederic Weisbecker Cc: Linus Torvalds Cc: Mel Gorman Cc: Oleg Nesterov Cc: Steven Rostedt Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/16205aee116772aa686814f9b13bccb562108047.1401902905.git.luto@amacapital.net Signed-off-by: Ingo Molnar --- kernel/sched/core.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'kernel') diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 5976ca579d3e..e4c0ddd3db8e 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -564,6 +564,8 @@ void resched_task(struct task_struct *p) if (set_nr_and_not_polling(p)) smp_send_reschedule(cpu); + else + trace_sched_wake_idle_without_ipi(cpu); } void resched_cpu(int cpu) @@ -647,6 +649,8 @@ static void wake_up_idle_cpu(int cpu) smp_mb(); if (!tsk_is_polling(rq->idle)) smp_send_reschedule(cpu); + else + trace_sched_wake_idle_without_ipi(cpu); } static bool wake_up_full_nohz_cpu(int cpu) -- cgit v1.2.3