From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422951AbcBQM1i (ORCPT ); Wed, 17 Feb 2016 07:27:38 -0500 Received: from terminus.zytor.com ([198.137.202.10]:56706 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422887AbcBQM1M (ORCPT ); Wed, 17 Feb 2016 07:27:12 -0500 Date: Wed, 17 Feb 2016 04:24:31 -0800 From: tip-bot for Thomas Gleixner Message-ID: Cc: jolsa@redhat.com, vincent.weaver@maine.edu, eranian@google.com, torvalds@linux-foundation.org, acme@redhat.com, hpa@zytor.com, peterz@infradead.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@kernel.org Reply-To: vincent.weaver@maine.edu, jolsa@redhat.com, eranian@google.com, peterz@infradead.org, hpa@zytor.com, acme@redhat.com, torvalds@linux-foundation.org, tglx@linutronix.de, mingo@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20160209201007.763417379@linutronix.de> References: <20160209201007.763417379@linutronix.de> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] perf/core: Remove the bogus and dangerous CPU_DOWN_FAILED hotplug state Git-Commit-ID: 27ca9236c96f4a21b72a2b4f08260efeab951bd0 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 27ca9236c96f4a21b72a2b4f08260efeab951bd0 Gitweb: http://git.kernel.org/tip/27ca9236c96f4a21b72a2b4f08260efeab951bd0 Author: Thomas Gleixner AuthorDate: Tue, 9 Feb 2016 20:11:26 +0000 Committer: Ingo Molnar CommitDate: Wed, 17 Feb 2016 10:37:29 +0100 perf/core: Remove the bogus and dangerous CPU_DOWN_FAILED hotplug state If CPU_DOWN_PREPARE fails the perf hotplug notifier is called for CPU_DOWN_FAILED and calls perf_event_init_cpu(), which checks whether the swhash is referenced. If yes it allocates a new hash and stores the pointer in the per cpu data structure. But at this point the cpu is still online, so there must be a valid hash already. By overwriting the pointer the existing hash is not longer accessible. Remove the CPU_DOWN_FAILED state, as there is nothing to (re)allocate. Signed-off-by: Thomas Gleixner Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Vince Weaver Link: http://lkml.kernel.org/r/20160209201007.763417379@linutronix.de Signed-off-by: Ingo Molnar --- kernel/events/core.c | 1 - 1 file changed, 1 deletion(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 474ffea..4aa64a8 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9282,7 +9282,6 @@ perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) switch (action & ~CPU_TASKS_FROZEN) { case CPU_UP_PREPARE: - case CPU_DOWN_FAILED: perf_event_init_cpu(cpu); break;