From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754804AbdKNKcH (ORCPT ); Tue, 14 Nov 2017 05:32:07 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:55074 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753932AbdKNKbs (ORCPT ); Tue, 14 Nov 2017 05:31:48 -0500 From: Mark Rutland To: linux-kernel@vger.kernel.org Cc: Mark Rutland , Arnaldo Carvalho de Melo , Ingo Molnar , "Paul E . McKenney" , Peter Zijlstra Subject: [PATCH] perf mmap: Convert ACCESS_ONCE() to READ_ONCE() Date: Tue, 14 Nov 2017 10:31:38 +0000 Message-Id: <20171114103138.9931-1-mark.rutland@arm.com> X-Mailer: git-send-email 2.11.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Recently there was a treewide conversion of ACCESS_ONCE() to {READ,WRITE}_ONCE(), but a new use was introduced concurrently by commit: 1695849735752d2a ("perf mmap: Move perf_mmap and methods to separate mmap.[ch] files") Let's convert this over to READ_ONCE() so that we can remove the ACCESS_ONCE() definitions in subsequent patches. Signed-off-by: Mark Rutland Cc: Arnaldo Carvalho de Melo Cc: Ingo Molnar Cc: Paul E. McKenney Cc: Peter Zijlstra --- tools/perf/util/mmap.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Hi, Would it be possible for this to be taken as a fixup in an upcoming rc? That way we should be able to remove the ACCESS_ONCE() definitions prior to v4.15. Thanks, Mark. diff --git a/tools/perf/util/mmap.h b/tools/perf/util/mmap.h index efd78b827b05..3a5cb5a6e94a 100644 --- a/tools/perf/util/mmap.h +++ b/tools/perf/util/mmap.h @@ -70,7 +70,7 @@ void perf_mmap__read_catchup(struct perf_mmap *md); static inline u64 perf_mmap__read_head(struct perf_mmap *mm) { struct perf_event_mmap_page *pc = mm->base; - u64 head = ACCESS_ONCE(pc->data_head); + u64 head = READ_ONCE(pc->data_head); rmb(); return head; } -- 2.11.0