From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5FD11C07E9B for ; Sun, 11 Jul 2021 10:41:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4DAE66127C for ; Sun, 11 Jul 2021 10:41:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232520AbhGKKoT (ORCPT ); Sun, 11 Jul 2021 06:44:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48540 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232490AbhGKKoR (ORCPT ); Sun, 11 Jul 2021 06:44:17 -0400 Received: from mail-pl1-x62f.google.com (mail-pl1-x62f.google.com [IPv6:2607:f8b0:4864:20::62f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6B7CDC0613DD for ; Sun, 11 Jul 2021 03:41:31 -0700 (PDT) Received: by mail-pl1-x62f.google.com with SMTP id u3so2363880plf.5 for ; Sun, 11 Jul 2021 03:41:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=u/h6y01vhaIboCmoU5QTv0ntWs0BLu7zaNEJjRy0DS4=; b=Zj4Ser95niZXysKWnByhPGn7HehGVUfl7nnW2uuuLdWtt8FvTDn1DJtkiYlqAnXvOM 7WCBS51r0hic0n23bnvsFNPevM4yPDsBKiSvWwSn6nKFqz0PWzZv+RJRknCjQCOzsDPP EuyR+YEhdCXDh2knglL4Cu/TkXTQyTnW1vqwwxc/d4uqpucKLc+vqGtouhD/lHT+TTI8 VT+K2XW6Icb+WrhYViyqeM+3Tm37FrkfBGFycyasGrpZuIa2WUVlspB/+2NUJDmRWuX8 jQypzUWDQ7ynkeWluJoJvOUOLYONU5hyByk9uTPe4CWIvrRD31gehKnInez5iF2XZ4z3 OnKQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=u/h6y01vhaIboCmoU5QTv0ntWs0BLu7zaNEJjRy0DS4=; b=bPpCQ4vsXJVPZqvW15LtcgaO/fznbc8RvPzdhYRxiMRpheWIp8F67M0pfqVRszPzFl TLAlAErETzTD6IxgSy8qH9DZRD/8XO5NFV405JebTzM7K9vOmRGsDMEFZE+j5jXI1YxD snV5gW916OZm3r4bTyuoz/y6W5rOXaLt4RhAYhMSeQf/riRo7iG/9EOq4dvUv0Dgo6UD DnnsJPFLGPT8UfOrbR1gfe8CaF1isBHsqjN9c87s9XHWAyGlIFaOMWRs8jPm1I+LcY5h t7SzGKzE6+5aOmAXp8RvU5NksN1yqLihW2ewc75+UIjkugWncKIkL6e9ge50btG0kYmu g9xg== X-Gm-Message-State: AOAM5332KuZWe++iBzX1DIa1xEGns2ww3BohxgOwdhvvEYkRTDkpsfX7 fqsmyAmO/ffl6TvkpZdUXrb+U9XpK1vKAe4m X-Google-Smtp-Source: ABdhPJx2ZkD3Ke+xwOEnTb++Cdto4iZATSeueTetnce3xcHV5VkEW1GhkVilI+3vLAFjAjrNQ7Ftgw== X-Received: by 2002:a17:903:1243:b029:ed:8298:7628 with SMTP id u3-20020a1709031243b02900ed82987628mr38413186plh.11.1626000090951; Sun, 11 Jul 2021 03:41:30 -0700 (PDT) Received: from localhost ([103.127.241.250]) by smtp.gmail.com with ESMTPSA id w6sm14036962pgh.56.2021.07.11.03.41.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 11 Jul 2021 03:41:30 -0700 (PDT) From: Leo Yan To: Arnaldo Carvalho de Melo , Adrian Hunter , Peter Zijlstra , Ingo Molnar , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Thomas Gleixner , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , Mathieu Poirier , Suzuki K Poulose , Mike Leach , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org Cc: Leo Yan Subject: [PATCH v4 05/11] perf auxtrace: Use WRITE_ONCE() for updating aux_tail Date: Sun, 11 Jul 2021 18:40:59 +0800 Message-Id: <20210711104105.505728-6-leo.yan@linaro.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210711104105.505728-1-leo.yan@linaro.org> References: <20210711104105.505728-1-leo.yan@linaro.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org Use WRITE_ONCE() for updating aux_tail, so can avoid unexpected memory behaviour. Signed-off-by: Leo Yan Acked-by: Adrian Hunter Acked-by: Peter Zijlstra (Intel) --- tools/perf/util/auxtrace.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/util/auxtrace.h b/tools/perf/util/auxtrace.h index cc1c1b9cec9c..79227b8864cd 100644 --- a/tools/perf/util/auxtrace.h +++ b/tools/perf/util/auxtrace.h @@ -480,7 +480,7 @@ static inline void auxtrace_mmap__write_tail(struct auxtrace_mmap *mm, u64 tail) /* Ensure all reads are done before we write the tail out */ smp_mb(); #if BITS_PER_LONG == 64 || !defined(HAVE_SYNC_COMPARE_AND_SWAP_SUPPORT) - pc->aux_tail = tail; + WRITE_ONCE(pc->aux_tail, tail); #else do { old_tail = __sync_val_compare_and_swap(&pc->aux_tail, 0, 0); -- 2.25.1