From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755596Ab2JPH7f (ORCPT ); Tue, 16 Oct 2012 03:59:35 -0400 Received: from e23smtp05.au.ibm.com ([202.81.31.147]:44493 "EHLO e23smtp05.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755520Ab2JPH7d (ORCPT ); Tue, 16 Oct 2012 03:59:33 -0400 From: "Srivatsa S. Bhat" Subject: [RESEND PATCH 2/2] perf, cpu hotplug: Use cached value of smp_processor_id() To: peterz@infradead.org, acme@ghostprotocols.net Cc: mingo@kernel.org, tglx@linutronix.de, akpm@linux-foundation.org, paulmck@linux.vnet.ibm.com, srivatsa.bhat@linux.vnet.ibm.com, linux-kernel@vger.kernel.org Date: Tue, 16 Oct 2012 13:28:17 +0530 Message-ID: <20121016075817.3572.76733.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20121016075809.3572.47848.stgit@srivatsabhat.in.ibm.com> References: <20121016075809.3572.47848.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: 12101607-1396-0000-0000-000002009ABB 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 file changed, 4 insertions(+), 3 deletions(-) diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 0647805..6bfb2faa 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -803,15 +803,16 @@ 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)