From b986d7ec0f8b7ea3cc7366d80a137fbe839df227 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 20 May 2009 12:21:21 +0200 Subject: [PATCH] perf_counter: Optimize disable of time based sw counters Currently we call hrtimer_cancel() unconditionally on disable of time based software counters. Avoid when possible. [ Impact: micro-optimize the code ] Signed-off-by: Peter Zijlstra Cc: Paul Mackerras Cc: Corey Ashford Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Thomas Gleixner Cc: Marcelo Tosatti Cc: John Kacur LKML-Reference: <20090520102553.388185031@chello.nl> Signed-off-by: Ingo Molnar --- kernel/perf_counter.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index db02eb16c777..473ed2cafbfc 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -2716,7 +2716,8 @@ static int cpu_clock_perf_counter_enable(struct perf_counter *counter) static void cpu_clock_perf_counter_disable(struct perf_counter *counter) { - hrtimer_cancel(&counter->hw.hrtimer); + if (counter->hw.irq_period) + hrtimer_cancel(&counter->hw.hrtimer); cpu_clock_perf_counter_update(counter); } @@ -2767,7 +2768,8 @@ static int task_clock_perf_counter_enable(struct perf_counter *counter) static void task_clock_perf_counter_disable(struct perf_counter *counter) { - hrtimer_cancel(&counter->hw.hrtimer); + if (counter->hw.irq_period) + hrtimer_cancel(&counter->hw.hrtimer); task_clock_perf_counter_update(counter, counter->ctx->time); }