From patchwork Tue Nov 14 10:31:38 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Rutland X-Patchwork-Id: 118867 Delivered-To: patch@linaro.org Received: by 10.140.22.164 with SMTP id 33csp2866723qgn; Tue, 14 Nov 2017 02:32:10 -0800 (PST) X-Google-Smtp-Source: AGs4zMaCvkBDLrQ62Xz9JcoX4LMdnx/tc59OBuYePQVKb6Zd6vbDPMrox5Zg9cPNARciKI0slKnj X-Received: by 10.99.126.6 with SMTP id z6mr10431044pgc.305.1510655530548; Tue, 14 Nov 2017 02:32:10 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1510655530; cv=none; d=google.com; s=arc-20160816; b=fX7Gr6Gv7VRoy+wFcZp4u98L2Fir0fEhz4ePWsO4g+PC8yMyEnFJjCVMN1od3P5uQ1 ZQb8ohOGb6RqHs7ZXauWsMDCnzaWy9R80FdCu/P1aja8PYI7ruaZZIicBNZyEBNNI8Vh kKSSqVPX06Y3cHrqzGwAyr6vo/E64CgU7h03Nj8ZwTBxkg2DqYgTqXkgP17oA+8uNef1 AgBCzw1XWQTbZQ1Y1PA6WhMuTvsXrU6wVNBYNIth4SU45JbXii59N1/URJrR3u7aFi8o n0ZyiA9AGzoLksojsMcLtsNWiWCU+rbAzQq6MCRftujaNxRh/diWQF0gHvv6Sl9VS6W7 4fHQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:message-id:date:subject:cc:to:from :arc-authentication-results; bh=3ebmWDes3LRVj6QCF9qzULLTMm+kE315u5NPJiNzT+M=; b=IH9CajJK6hwws6tDUPBVhYKysqJw2ko6fgnmN0MplqJvnoxbJ8sI1DBcivNL+m8M+o U1NcpTw4kJPgU+I/iDQD6uwb2FAf4RsI30cDd6Y5/zrkp/tSi6E3uQR2N7/e2M3ioiQI NdvLlyOeV5Wz9l3GOvmNeJd4aiFMzbkvrXs4IwhCKzvXewhAyBbAQGrHqG/9QtR94STI xkKoHI0sWJ+sk8t+jQCB0iCmDrl1Dz0+YrQQimpA4VPA1DHCp6R/w7+04tpRL7837yWH 14y06i8OzVB4sp/edFaa0HNYBgQD25+Lan92U6J+wbAnxFINj1/G/TpEV1muSeFapKig 5wZA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id t64si4434319pfj.332.2017.11.14.02.32.10; Tue, 14 Nov 2017 02:32:10 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754806AbdKNKcH (ORCPT + 27 others); 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 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6F53D1435; Tue, 14 Nov 2017 02:31:48 -0800 (PST) Received: from localhost.localdomain (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 1943C3F58F; Tue, 14 Nov 2017 02:31:46 -0800 (PST) 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 Precedence: bulk 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. -- 2.11.0 Reviewed-by: Paul E. McKenney 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; }