From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754321AbcHXLpp (ORCPT ); Wed, 24 Aug 2016 07:45:45 -0400 Received: from mga03.intel.com ([134.134.136.65]:25546 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753937AbcHXLpn (ORCPT ); Wed, 24 Aug 2016 07:45:43 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.28,570,1464678000"; d="scan'208";a="870396030" From: Alexander Shishkin To: Will Deacon Cc: Vince Weaver , Linux Kernel Mailing List , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo Subject: Re: perf: WARNING: kernel/events/core.c:4893 perf_mmap_close In-Reply-To: <20160824091905.GA16944@arm.com> References: <87k2fqmska.fsf@ashishki-desk.ger.corp.intel.com> <20160823151239.GA29462@arm.com> <87vayrl8fs.fsf@ashishki-desk.ger.corp.intel.com> <20160824091905.GA16944@arm.com> User-Agent: Notmuch/0.21 (http://notmuchmail.org) Emacs/24.5.1 (x86_64-pc-linux-gnu) Date: Wed, 24 Aug 2016 14:44:12 +0300 Message-ID: <87pooyl7cj.fsf@ashishki-desk.ger.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Will Deacon writes: > A little bit of digging suggests that the preempt count isn't balanced > across the call to perf_pmu_output_stop from perf_mmap_close. Further > digging revealed the unbalanced get_cpu_ptr in __perf_pmu_output_stop. > Fix below! Oh gee, that's embarrassing. Thanks! > This patch uses this_cpu_ptr instead of get_cpu_ptr, since preemption is > already disabled by the caller. > > Fixes: 95ff4ca26c49 ("perf/core: Free AUX pages in unmap path") > Cc: Alexander Shishkin > Cc: Peter Zijlstra > Signed-off-by: Will Deacon Reviewed-by: Alexander Shishkin Regards, -- Alex