diff options
| author | Andy Lutomirski <[email protected]> | 2014-06-04 10:31:15 -0700 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2014-06-05 12:09:50 +0200 |
| commit | dfc68f29ae67f2a6e799b44e6a4eb3417dffbfcd (patch) | |
| tree | 3c91426549e3e5e5c04104f083150e8aa7994cdc | |
| parent | 84c407084137d4e491b07ea5ff8665d19106a5ac (diff) | |
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 <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: David Ahern <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/16205aee116772aa686814f9b13bccb562108047.1401902905.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <[email protected]>
| -rw-r--r-- | include/trace/events/sched.h | 20 | ||||
| -rw-r--r-- | kernel/sched/core.c | 4 |
2 files changed, 24 insertions, 0 deletions
diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h index 67e1bbf83695..0a68d5ae584e 100644 --- a/include/trace/events/sched.h +++ b/include/trace/events/sched.h @@ -530,6 +530,26 @@ TRACE_EVENT(sched_swap_numa, __entry->dst_pid, __entry->dst_tgid, __entry->dst_ngid, __entry->dst_cpu, __entry->dst_nid) ); + +/* + * Tracepoint for waking a polling cpu without an IPI. + */ +TRACE_EVENT(sched_wake_idle_without_ipi, + + TP_PROTO(int cpu), + + TP_ARGS(cpu), + + TP_STRUCT__entry( + __field( int, cpu ) + ), + + TP_fast_assign( + __entry->cpu = cpu; + ), + + TP_printk("cpu=%d", __entry->cpu) +); #endif /* _TRACE_SCHED_H */ /* This part must be outside protection */ 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) |