From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758089Ab2IMOnB (ORCPT ); Thu, 13 Sep 2012 10:43:01 -0400 Received: from e28smtp02.in.ibm.com ([122.248.162.2]:59055 "EHLO e28smtp02.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758077Ab2IMOm6 (ORCPT ); Thu, 13 Sep 2012 10:42:58 -0400 From: "Srivatsa S. Bhat" Subject: [PATCH 2/2] perf, cpu hotplug: Use cached value of smp_processor_id() To: a.p.zijlstra@chello.nl, acme@infradead.org Cc: mingo@kernel.org, paulus@samba.org, linux-kernel@vger.kernel.org, "Srivatsa S. Bhat" Date: Thu, 13 Sep 2012 20:12:26 +0530 Message-ID: <20120913144226.3426.93144.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20120913144220.3426.22392.stgit@srivatsabhat.in.ibm.com> References: <20120913144220.3426.22392.stgit@srivatsabhat.in.ibm.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit x-cbid: 12091314-5816-0000-0000-000004717E50 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The perf_cpu_notifier() macro invokes smp_processor_id() multiple times. Optimize it by using a local variable. Signed-off-by: Srivatsa S. Bhat --- include/linux/perf_event.h | 7 ++++--- 1 files changed, 4 insertions(+), 3 deletions(-) diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index cc4574d..5b5b017 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1346,15 +1346,16 @@ static inline void perf_event_task_tick(void) { } do { \ static struct notifier_block fn##_nb __cpuinitdata = \ { .notifier_call = fn, .priority = CPU_PRI_PERF }; \ + unsigned long cpu = smp_processor_id(); \ unsigned long flags; \ fn(&fn##_nb, (unsigned long)CPU_UP_PREPARE, \ - (void *)(unsigned long)smp_processor_id()); \ + (void *)(unsigned long)cpu); \ local_irq_save(flags); \ fn(&fn##_nb, (unsigned long)CPU_STARTING, \ - (void *)(unsigned long)smp_processor_id()); \ + (void *)(unsigned long)cpu); \ local_irq_restore(flags); \ fn(&fn##_nb, (unsigned long)CPU_ONLINE, \ - (void *)(unsigned long)smp_processor_id()); \ + (void *)(unsigned long)cpu); \ register_cpu_notifier(&fn##_nb); \ } while (0)