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 7BD08C47082 for ; Mon, 7 Jun 2021 10:37:21 +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 4727C611C0 for ; Mon, 7 Jun 2021 10:37:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4727C611C0 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=wqHQea1jBD2JApxUb1co5LGndyroq2LiytPHGVYUBeE=; b=ohq8wnJxjrjTwN64JQVsjgtIIX 26wFDhgtDGQFl6ZJXZyZJCtMlVR5U0p0uYK34StCkQP595yay0xp5oQEj1wemJ1DaenbHB0H7u1ra acVP2NH1w0X4SIpVQy2Ldm7pAUoFhxt2OE8ZaEiflblPnZ8LoGDgs5zhdfSDalhHdemcfpDdW2oQu hdVn+gs+1B/BdTkDPT4+/gkoM1dZk/0w/6j2o2ArIwZmQh/ttLQsvpjwcAmGZlQjLWX7P9DrZIYcZ T+JgmcPFOmpTvVNa4pFrMTwG5vwEM88kd2fkHoitireYHjnI3ebe4ME6SnGJfxPsoPWxveW4WDP5K 1vf7cH1A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1lqCbG-002xwp-QA; Mon, 07 Jun 2021 10:35:19 +0000 Received: from mga03.intel.com ([134.134.136.65]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1lqC5e-002m13-ED for linux-arm-kernel@lists.infradead.org; Mon, 07 Jun 2021 10:02:43 +0000 IronPort-SDR: NA5Qf3aOVXu3r5QcsMdGBhr1ebvXOd7BiC0KLEnZu3Q6DIqwhXM/lcE58KUS4NRA5YzIZbdb6x 4wESFVaMt0nA== X-IronPort-AV: E=McAfee;i="6200,9189,10007"; a="204614888" X-IronPort-AV: E=Sophos;i="5.83,254,1616482800"; d="scan'208";a="204614888" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Jun 2021 03:02:37 -0700 IronPort-SDR: n/77u5nQ23NkboK2RAmtfAn0Ro78k9O/tBE31r6buWmyj1Zh4y4nqUH4tyaCC8JRH3VvcYUnlh 9RwcHSPmZaUw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.83,254,1616482800"; d="scan'208";a="484722858" 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 03:02:32 -0700 Subject: Re: [PATCH v2 5/8] perf auxtrace: Change to use SMP memory barriers 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> <20210602103007.184993-6-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 13:02:50 +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: <20210602103007.184993-6-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_030238_543911_0C5C4E89 X-CRM114-Status: GOOD ( 22.08 ) 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: > The kernel and the userspace tool can access the AUX ring buffer head > and tail from different CPUs, thus SMP class of barriers are required > on SMP system. > > This patch changes to use SMP barriers to replace mb() and rmb() > barriers. > > Signed-off-by: Leo Yan Acked-by: Adrian Hunter > --- > tools/perf/util/auxtrace.h | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/tools/perf/util/auxtrace.h b/tools/perf/util/auxtrace.h > index a4fbb33b7245..42b7ef811bde 100644 > --- a/tools/perf/util/auxtrace.h > +++ b/tools/perf/util/auxtrace.h > @@ -444,7 +444,7 @@ static inline u64 auxtrace_mmap__read_snapshot_head(struct auxtrace_mmap *mm) > u64 head = READ_ONCE(pc->aux_head); > > /* Ensure all reads are done after we read the head */ > - rmb(); > + smp_rmb(); > return head; > } > > @@ -458,7 +458,7 @@ static inline u64 auxtrace_mmap__read_head(struct auxtrace_mmap *mm) > #endif > > /* Ensure all reads are done after we read the head */ > - rmb(); > + smp_rmb(); > return head; > } > > @@ -470,7 +470,7 @@ static inline void auxtrace_mmap__write_tail(struct auxtrace_mmap *mm, u64 tail) > #endif > > /* Ensure all reads are done before we write the tail out */ > - mb(); > + smp_mb(); > #if BITS_PER_LONG == 64 || !defined(HAVE_SYNC_COMPARE_AND_SWAP_SUPPORT) > pc->aux_tail = tail; > #else > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel