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=-15.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 0AD11C47094 for ; Mon, 7 Jun 2021 10:38:28 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C1C30610A2 for ; Mon, 7 Jun 2021 10:38:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C1C30610A2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date: Message-ID:From:References:To:Subject:Reply-To:Cc:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=RBkHXlmAzi9HX6X7mhGz7zeYmZcMXSFDtohsSjFfmsw=; b=loRal8j8euwGPO5zDYNzCVKHh9 JtgnNxxZlMh+Sj5zujGl898gBMKHf9f0XHekwgOAXEg/rwD9PyeO8uQ2UwyQ/asIoPRXIxIextGEU /P1bUxU1mguESQUkVBDTG5PIbZ5SjGys9ADzoz81i+qHDgCp5+d3L5laAJ0h7bt6VuRsgywzxMJBU XCVLb2Mrle1bsvkijElAH9S1ziR3wOx2aLHsVIoImRhTQ9GM3PqQ6KK+6a6mJhrK6aEu+TlBG1Aun BURmz3p5QPdvqLHAnTelwmT26+o7Hb4aRUCorRRjaaUUYv/7gHXHa+Q1XC2fLgjhjKQol1oHqcORB y3cU1Mpg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1lqCcI-002yZc-R1; Mon, 07 Jun 2021 10:36:23 +0000 Received: from mga09.intel.com ([134.134.136.24]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1lqC6C-002mBI-1i for linux-arm-kernel@lists.infradead.org; Mon, 07 Jun 2021 10:03:17 +0000 IronPort-SDR: qzAjwLGnZ7PClHPLEJzaNB3SrIw4JkM9EtpTT29XZiZb6eUPg06b4yo+RX5DaZC0ciiwVDa3te 5njtAULV9lCA== X-IronPort-AV: E=McAfee;i="6200,9189,10007"; a="204563534" X-IronPort-AV: E=Sophos;i="5.83,254,1616482800"; d="scan'208";a="204563534" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Jun 2021 03:03:10 -0700 IronPort-SDR: cbVVM/RFVTOe4XSIG7lwLwdbgOmk2k7ZtwC1WPlisFYzxgfhY0yfh0NbxQ3HFRKIJ9ZCrEnjrx gpWRjhYPNSrA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.83,254,1616482800"; d="scan'208";a="484723038" Received: from ahunter-desktop.fi.intel.com (HELO [10.237.72.174]) ([10.237.72.174]) by fmsmga002.fm.intel.com with ESMTP; 07 Jun 2021 03:03:06 -0700 Subject: Re: [PATCH v2 7/8] perf auxtrace: Use WRITE_ONCE() for updating aux_tail To: Leo Yan , Arnaldo Carvalho de Melo , Peter Zijlstra , Ingo Molnar , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Thomas Gleixner , x86@kernel.org, "H. Peter Anvin" , Mathieu Poirier , Suzuki K Poulose , Mike Leach , Andi Kleen , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org References: <20210602103007.184993-1-leo.yan@linaro.org> <20210602103007.184993-8-leo.yan@linaro.org> From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Message-ID: Date: Mon, 7 Jun 2021 13:03:24 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: <20210602103007.184993-8-leo.yan@linaro.org> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210607_030312_179524_34D2EE0E X-CRM114-Status: GOOD ( 19.79 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2/06/21 1:30 pm, Leo Yan wrote: > Use WRITE_ONCE() for updating aux_tail, so can avoid unexpected memory > behaviour. > > Signed-off-by: Leo Yan Acked-by: Adrian Hunter > --- > 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 e625bc76cdde..abc4282f5272 100644 > --- a/tools/perf/util/auxtrace.h > +++ b/tools/perf/util/auxtrace.h > @@ -458,7 +458,7 @@ 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(); > - pc->aux_tail = tail; > + WRITE_ONCE(pc->aux_tail, tail); > } > > int auxtrace_mmap__mmap(struct auxtrace_mmap *mm, > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel