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,URIBL_BLOCKED, 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 1D9ACC432BE for ; Mon, 9 Aug 2021 11:15:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 04671610A7 for ; Mon, 9 Aug 2021 11:15:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235039AbhHILPz (ORCPT ); Mon, 9 Aug 2021 07:15:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57094 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235003AbhHILPt (ORCPT ); Mon, 9 Aug 2021 07:15:49 -0400 Received: from mail-pj1-x102a.google.com (mail-pj1-x102a.google.com [IPv6:2607:f8b0:4864:20::102a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E3249C0613D3 for ; Mon, 9 Aug 2021 04:15:28 -0700 (PDT) Received: by mail-pj1-x102a.google.com with SMTP id j18-20020a17090aeb12b029017737e6c349so19006279pjz.0 for ; Mon, 09 Aug 2021 04:15:28 -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=Icy+Z5PUT8u8Dpc5dkfKGlMZmq16q7ysRKkB/tucaTI=; b=g/ZYxqNSVYfAFHS8Y3Q3LzN7lJVW0gpKxk0VOgH2xoHxQ2NKRV+6csjIvgyrBywe+R ltqX4DJvWgANRw6Nqe8rUwmSIG+EDpqswEY0E+CfJ/O//FkSNNgnONSqBD52NBgheHqf IL+wA/2mBW0nWKRFKTNOTKsUawDafYB7PEly8exN+kIZ5jNUcK1KLqO9Dv498JOnhgtn lOPBbeeSBqs5TUIxc7BkRpvOakIRWVcxw0bGa7bs44s7HueWVPIuULbCQwrnovXyAjN4 iEqu1DIH3tJr1THGFTL8yGEUVs6AytYqfeczR72X6Dpe58kkFXlTkoE8PmF6NpOpUN4G elHw== 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=Icy+Z5PUT8u8Dpc5dkfKGlMZmq16q7ysRKkB/tucaTI=; b=D7Htgogpfbtqk+VYBu837zuIhaNVHHbbln668gZBEgOyScCA2HTYe+Wr8rZG1eoJQW aHqTUKRoSm5EcKJ/y6JgNvVFUNDe8hemSxi433/EJzISTcvhRT7eHRDvHFmhmge2OuzE OttJu4QCEeY4ZPEKFCz59v1Kjn52wlTDjoroZj/4HSIqBI5uE9T9m+6W7K8YH6FrxGA3 K/ALcMAjFjCg6OnOmO1iyP2IzibAiPANmr4qYD40ydihlZ/qoejAodqx/gK5S0aD3+Hq yfPhtFu0GrSahirY9/EhB28NQ/5mOcAhrgq+hQtOyVo65vF7a9W0TegbRKj3OA15xhF6 adFg== X-Gm-Message-State: AOAM531P1g8c2Mcesw/0eM+KHbftjKj0S5v6kzNa9BTT6CcRSNpU7tcb yZ/BJ0f9j4zJqjGwZWn5ROnpiA== X-Google-Smtp-Source: ABdhPJyNV8pgx/xOzD9VU7toSF2rH3xwT8aKSjCPECncWnnPs/WlkFT7R4RMV2uLO/EZwqlldYgXEg== X-Received: by 2002:a17:902:ce8f:b029:12c:c4e7:682d with SMTP id f15-20020a170902ce8fb029012cc4e7682dmr19964157plg.58.1628507728380; Mon, 09 Aug 2021 04:15:28 -0700 (PDT) Received: from localhost ([210.0.159.74]) by smtp.gmail.com with ESMTPSA id 136sm23941683pge.77.2021.08.09.04.15.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 09 Aug 2021 04:15:27 -0700 (PDT) From: Leo Yan To: Arnaldo Carvalho de Melo , Peter Zijlstra , Adrian Hunter , Ingo Molnar , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Thomas Gleixner , Borislav Petkov , "H. Peter Anvin" , Mathieu Poirier , Suzuki K Poulose , Mike Leach , Michael Petlan , "Frank Ch. Eigler" , Song Liu , x86@kernel.org, =?UTF-8?q?Daniel=20D=C3=ADaz?= , Andrii Nakryiko , Alexei Starovoitov , Sedat Dilek , Andi Kleen , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, coresight@lists.linaro.org Cc: Leo Yan Subject: [PATCH v5 4/9] perf/x86: Add compiler barrier after updating BTS Date: Mon, 9 Aug 2021 19:14:02 +0800 Message-Id: <20210809111407.596077-5-leo.yan@linaro.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210809111407.596077-1-leo.yan@linaro.org> References: <20210809111407.596077-1-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 Since BTS is coherent, simply add a compiler barrier to separate the BTS update and aux_head store. Signed-off-by: Leo Yan --- arch/x86/events/intel/bts.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/x86/events/intel/bts.c b/arch/x86/events/intel/bts.c index 6320d2cfd9d3..974e917e65b2 100644 --- a/arch/x86/events/intel/bts.c +++ b/arch/x86/events/intel/bts.c @@ -209,6 +209,12 @@ static void bts_update(struct bts_ctx *bts) } else { local_set(&buf->data_size, head); } + + /* + * Since BTS is coherent, just add compiler barrier to ensure + * BTS updating is ordered against bts::handle::event. + */ + barrier(); } static int -- 2.25.1