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authorAndy Lutomirski <luto@amacapital.net>2014-06-04 10:31:15 -0700
committerIngo Molnar <mingo@kernel.org>2014-06-05 12:09:50 +0200
commitdfc68f29ae67f2a6e799b44e6a4eb3417dffbfcd (patch)
tree3c91426549e3e5e5c04104f083150e8aa7994cdc /kernel
parent84c407084137d4e491b07ea5ff8665d19106a5ac (diff)
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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 <luto@amacapital.net> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: nicolas.pitre@linaro.org Cc: daniel.lezcano@linaro.org Cc: umgwanakikbuti@gmail.com Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/16205aee116772aa686814f9b13bccb562108047.1401902905.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/sched/core.c4
1 files changed, 4 insertions, 0 deletions
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)