From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932967AbdDRTvX (ORCPT ); Tue, 18 Apr 2017 15:51:23 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:53155 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932890AbdDRTvD (ORCPT ); Tue, 18 Apr 2017 15:51:03 -0400 Message-Id: <20170418170554.043759892@linutronix.de> User-Agent: quilt/0.63-1 Date: Tue, 18 Apr 2017 19:05:02 +0200 From: Thomas Gleixner To: LKML Cc: Peter Zijlstra , Ingo Molnar , Steven Rostedt , Sebastian Siewior Subject: [patch V2 20/24] perf/core: Remove redundant get_online_cpus() References: <20170418170442.665445272@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Disposition: inline; filename=perf--Remove-redundant-get_online_cpus--.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org SyS_perf_event_open() calls get_online_cpus() and eventually invokes swevent_hlist_get() which does it again. All callchains leading to swevent_hlist_get() originate from SyS_perf_event_open() so the extra protection is redundant. Remove it. Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra --- kernel/events/core.c | 5 ----- 1 file changed, 5 deletions(-) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7592,7 +7592,6 @@ static int swevent_hlist_get(void) { int err, cpu, failed_cpu; - get_online_cpus(); for_each_possible_cpu(cpu) { err = swevent_hlist_get_cpu(cpu); if (err) { @@ -7600,8 +7599,6 @@ static int swevent_hlist_get(void) goto fail; } } - put_online_cpus(); - return 0; fail: for_each_possible_cpu(cpu) { @@ -7609,8 +7606,6 @@ static int swevent_hlist_get(void) break; swevent_hlist_put_cpu(cpu); } - - put_online_cpus(); return err; }