From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757930AbZFWKFA (ORCPT ); Tue, 23 Jun 2009 06:05:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757421AbZFWKEf (ORCPT ); Tue, 23 Jun 2009 06:04:35 -0400 Received: from hera.kernel.org ([140.211.167.34]:33670 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757840AbZFWKEd (ORCPT ); Tue, 23 Jun 2009 06:04:33 -0400 Date: Tue, 23 Jun 2009 10:04:11 GMT From: tip-bot for Peter Zijlstra To: linux-tip-commits@vger.kernel.org Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, a.p.zijlstra@chello.nl, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl, tglx@linutronix.de, mingo@elte.hu In-Reply-To: References: Subject: [tip:perfcounters/urgent] perf_counter: Optimize perf_counter_alloc()'s inherit case Message-ID: Git-Commit-ID: f344011ccb85469445369153c3d27c4ee4bc2ac8 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]); Tue, 23 Jun 2009 10:04:12 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: f344011ccb85469445369153c3d27c4ee4bc2ac8 Gitweb: http://git.kernel.org/tip/f344011ccb85469445369153c3d27c4ee4bc2ac8 Author: Peter Zijlstra AuthorDate: Mon, 22 Jun 2009 13:58:35 +0200 Committer: Ingo Molnar CommitDate: Tue, 23 Jun 2009 11:42:46 +0200 perf_counter: Optimize perf_counter_alloc()'s inherit case We don't need to add usage counts for swcounter and attr usage models for inherited counters since the parent counter will always have one, which suffices to generate the needed output. This avoids up to 3 global atomic increments per inherited counter. LKML-Reference: Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar --- kernel/perf_counter.c | 32 ++++++++++++++++++++------------ 1 files changed, 20 insertions(+), 12 deletions(-) diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 0a45490..c2b19c1 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -1508,11 +1508,13 @@ static void free_counter(struct perf_counter *counter) { perf_pending_sync(counter); - atomic_dec(&nr_counters); - if (counter->attr.mmap) - atomic_dec(&nr_mmap_counters); - if (counter->attr.comm) - atomic_dec(&nr_comm_counters); + if (!counter->parent) { + atomic_dec(&nr_counters); + if (counter->attr.mmap) + atomic_dec(&nr_mmap_counters); + if (counter->attr.comm) + atomic_dec(&nr_comm_counters); + } if (counter->destroy) counter->destroy(counter); @@ -3515,6 +3517,8 @@ static void sw_perf_counter_destroy(struct perf_counter *counter) { u64 event = counter->attr.config; + WARN_ON(counter->parent); + atomic_dec(&perf_swcounter_enabled[event]); } @@ -3551,8 +3555,10 @@ static const struct pmu *sw_perf_counter_init(struct perf_counter *counter) case PERF_COUNT_SW_PAGE_FAULTS_MAJ: case PERF_COUNT_SW_CONTEXT_SWITCHES: case PERF_COUNT_SW_CPU_MIGRATIONS: - atomic_inc(&perf_swcounter_enabled[event]); - counter->destroy = sw_perf_counter_destroy; + if (!counter->parent) { + atomic_inc(&perf_swcounter_enabled[event]); + counter->destroy = sw_perf_counter_destroy; + } pmu = &perf_ops_generic; break; } @@ -3663,11 +3669,13 @@ done: counter->pmu = pmu; - atomic_inc(&nr_counters); - if (counter->attr.mmap) - atomic_inc(&nr_mmap_counters); - if (counter->attr.comm) - atomic_inc(&nr_comm_counters); + if (!counter->parent) { + atomic_inc(&nr_counters); + if (counter->attr.mmap) + atomic_inc(&nr_mmap_counters); + if (counter->attr.comm) + atomic_inc(&nr_comm_counters); + } return counter; }