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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 40E60C433F5 for ; Tue, 14 Sep 2021 10:05:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B9B1610A6 for ; Tue, 14 Sep 2021 10:05:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229907AbhINKGq (ORCPT ); Tue, 14 Sep 2021 06:06:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60922 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230223AbhINKGp (ORCPT ); Tue, 14 Sep 2021 06:06:45 -0400 Received: from mail-pj1-x1035.google.com (mail-pj1-x1035.google.com [IPv6:2607:f8b0:4864:20::1035]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 69C95C061574 for ; Tue, 14 Sep 2021 03:05:28 -0700 (PDT) Received: by mail-pj1-x1035.google.com with SMTP id f3-20020a17090a638300b00199097ddf1aso1759949pjj.0 for ; Tue, 14 Sep 2021 03:05:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=z1muzdOPWzB0ytDKcRa+QFyNrcjjCHiCUrUvKj8zYFM=; b=ZV9YpuPTdGrvhLZWC7YTDjzQ+oyE4Tnvnl2GIQvc69ojO1KtUMsUfiP9jbd3N04ASM JSv+PVbTCW622AwkynaZ0Dj/sHs9nNGOzTgnmEOuguzXMzE+UMuDLtnQA+7BM07LZfB6 q5TmSMD1rnsXyGKCFILbsVrXFHZn1SlA0lfUa4GVO25uojNy0n+O0Y7EMjBj8B0HaVFX 0r81qzhcYX1QCmSPgFTKdnq6ytpycu4hgs/q7/XFqfX/4g8tGPY2dALaQtmcn44vk8I+ DPDSduio6Ba8YeMc1isvG99CxKGYwUeAoBDymzxWpAI2oHcMj/2uqQduBfu6/o7PUv61 NS2w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=z1muzdOPWzB0ytDKcRa+QFyNrcjjCHiCUrUvKj8zYFM=; b=cAw3toRRgy/+gImYrMgfSEk1QVpepOLuBOZQ3dRhzVVddbc1L3qsbzj/QCLAfMm919 d4Vh+4QVekZMehPe8gS0RD3EKTBMC6QZ/pUtjQnjkvMgLrT483sH+SmSByXfB9z2qZeM ZTOKz7hu9wa92UJMMrk1VpncLTt/t1rJhpD1n5MIC8WbHbWx5IZ9NlYjFCCNVIgzptc2 pS84VNnldV/naPwa+/fX1HNibeXe6V/H8hZsgKoZfBzLSJMWyGbd/gdfONiYDkG1MZBf QcrW5pcUcz6ayarEgC/nnSI0OV7xctJW2U0T6OHp4c0hB5xuZCfp6CAAjzAmgk/whQRO +unw== X-Gm-Message-State: AOAM532fv6z7YtyEDJjynLiZnbKZDALKQSSA2Hc5DWDSza/Mt2MTqv2o x8DGu3G2Y107aF3FAHqrHOfYig== X-Google-Smtp-Source: ABdhPJw9bLFl5o1rEO6GGn86+0NLilPqU7PnCPV4PRYgtLRqPF5710VvVQ1ig7++JmoZFGHm1n8mQQ== X-Received: by 2002:a17:90a:b392:: with SMTP id e18mr1151791pjr.205.1631613927864; Tue, 14 Sep 2021 03:05:27 -0700 (PDT) Received: from leoy-ThinkPad-X240s ([204.124.181.224]) by smtp.gmail.com with ESMTPSA id d5sm1082133pjs.53.2021.09.14.03.05.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 14 Sep 2021 03:05:27 -0700 (PDT) Date: Tue, 14 Sep 2021 18:05:17 +0800 From: Leo Yan To: Peter Zijlstra Cc: Arnaldo Carvalho de Melo , 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, Daniel =?iso-8859-1?Q?D=EDaz?= , Andrii Nakryiko , Alexei Starovoitov , Sedat Dilek , Andi Kleen , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, coresight@lists.linaro.org Subject: Re: [PATCH v5 4/9] perf/x86: Add compiler barrier after updating BTS Message-ID: <20210914100517.GC1538480@leoy-ThinkPad-X240s> References: <20210809111407.596077-1-leo.yan@linaro.org> <20210809111407.596077-5-leo.yan@linaro.org> <20210829105657.GC14461@leoy-ThinkPad-X240s> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org Hi Peter, On Tue, Sep 14, 2021 at 11:51:36AM +0200, Peter Zijlstra wrote: > On Sun, Aug 29, 2021 at 06:56:57PM +0800, Leo Yan wrote: > > Hi Peter, or any x86 maintainer, > > > > On Mon, Aug 09, 2021 at 07:14:02PM +0800, Leo Yan wrote: > > > Since BTS is coherent, simply add a compiler barrier to separate the BTS > > > update and aux_head store. > > > > Could you reivew this patch and check if BTS needs the comipler > > barrier in this case? Thanks. > > Yes, a compiler barrier is sufficient. > > You want me to pick it up? Maybe other maintainers are more suitable than me to answer this :) Yeah, I think it's great if you could pick it. Thanks, Leo