From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756727AbZETRTt (ORCPT ); Wed, 20 May 2009 13:19:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755247AbZETRTl (ORCPT ); Wed, 20 May 2009 13:19:41 -0400 Received: from hera.kernel.org ([140.211.167.34]:48371 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755785AbZETRTk (ORCPT ); Wed, 20 May 2009 13:19:40 -0400 Date: Wed, 20 May 2009 17:19:09 GMT From: tip-bot for Peter Zijlstra To: linux-tip-commits@vger.kernel.org Cc: linux-kernel@vger.kernel.org, acme@redhat.com, paulus@samba.org, hpa@zytor.com, mingo@redhat.com, jkacur@redhat.com, a.p.zijlstra@chello.nl, mtosatti@redhat.com, tglx@linutronix.de, cjashfor@linux.vnet.ibm.com, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, paulus@samba.org, acme@redhat.com, linux-kernel@vger.kernel.org, jkacur@redhat.com, a.p.zijlstra@chello.nl, mtosatti@redhat.com, tglx@linutronix.de, cjashfor@linux.vnet.ibm.com, mingo@elte.hu In-Reply-To: <20090520102553.388185031@chello.nl> References: <20090520102553.388185031@chello.nl> Subject: [tip:perfcounters/core] perf_counter: Optimize disable of time based sw counters Message-ID: Git-Commit-ID: b986d7ec0f8b7ea3cc7366d80a137fbe839df227 X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Wed, 20 May 2009 17:19:10 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: b986d7ec0f8b7ea3cc7366d80a137fbe839df227 Gitweb: http://git.kernel.org/tip/b986d7ec0f8b7ea3cc7366d80a137fbe839df227 Author: Peter Zijlstra AuthorDate: Wed, 20 May 2009 12:21:21 +0200 Committer: Ingo Molnar CommitDate: Wed, 20 May 2009 12:43:33 +0200 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 files changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index db02eb1..473ed2c 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); }