From 75e0678e7095c486a1b39ea560f8eb51a2714d6d Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sun, 10 May 2015 01:23:35 +0200 Subject: [PATCH] PM / tick: Add tracepoints for suspend-to-idle diagnostics Add suspend/resume tracepoints to tick_freeze() and tick_unfreeze() to catch when timekeeping is suspended and resumed during suspend-to-idle so as to be able to check whether or not we enter the "frozen" state and to measure the time spent in it. Signed-off-by: Rafael J. Wysocki Acked-by: Thomas Gleixner --- kernel/time/tick-common.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c index 3ae6afa1eb98..80c043052487 100644 --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -19,6 +19,7 @@ #include #include #include +#include #include @@ -457,10 +458,13 @@ void tick_freeze(void) raw_spin_lock(&tick_freeze_lock); tick_freeze_depth++; - if (tick_freeze_depth == num_online_cpus()) + if (tick_freeze_depth == num_online_cpus()) { + trace_suspend_resume(TPS("timekeeping_freeze"), + smp_processor_id(), true); timekeeping_suspend(); - else + } else { tick_suspend_local(); + } raw_spin_unlock(&tick_freeze_lock); } @@ -478,10 +482,13 @@ void tick_unfreeze(void) { raw_spin_lock(&tick_freeze_lock); - if (tick_freeze_depth == num_online_cpus()) + if (tick_freeze_depth == num_online_cpus()) { timekeeping_resume(); - else + trace_suspend_resume(TPS("timekeeping_freeze"), + smp_processor_id(), false); + } else { tick_resume_local(); + } tick_freeze_depth--; -- 2.20.1