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=-8.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 B0B16C433E0 for ; Thu, 16 Jul 2020 05:23:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 795B02067D for ; Thu, 16 Jul 2020 05:23:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="OstnAz+k" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726027AbgGPFW7 (ORCPT ); Thu, 16 Jul 2020 01:22:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47906 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725270AbgGPFW6 (ORCPT ); Thu, 16 Jul 2020 01:22:58 -0400 Received: from mail-pg1-x544.google.com (mail-pg1-x544.google.com [IPv6:2607:f8b0:4864:20::544]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7A62CC061755 for ; Wed, 15 Jul 2020 22:22:58 -0700 (PDT) Received: by mail-pg1-x544.google.com with SMTP id d4so4263797pgk.4 for ; Wed, 15 Jul 2020 22:22:58 -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:user-agent; bh=aw4OnsBnQ1ZIF1KX9lKuewx7m/jmsDZj2NNKkOvAmmo=; b=OstnAz+kmVxmVY/pV/REV0jbtqLRwPw8QmSZNb7DyqWS5efrtsTr5dXHD1jMz94Kzy 7feHtFTcHS4mdfpN1EEfwwzm81QIHzCk/SE52lfYe5kLAoU/EM/Sx5LiupOUsvAeX31F fxhfzpYagDFZNVe767d03rY6Mk3BzieN8OOgtC1PrLymM0JXNh+VRjInChygocN2gUSO JJSZn6Fzz0Pl2jKhTiELdjXrnGtSMRYOL76tYeBa2zWuwvuSDfSoHoT9DC7NVDqqg1E0 NQD4Z21GCwjV1GHJc7w76zxZBEVgGCa3+cMLSJpcaUPTwPQf3TmyHsO1bzk6zHPJN74Y ebxg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=aw4OnsBnQ1ZIF1KX9lKuewx7m/jmsDZj2NNKkOvAmmo=; b=OHTZoXLYo8Nl6bXs8VcVMnat1sqVOktsV0OezTHLBpnLFz1ld7F8Y1x098kMGQB2op fCnRmEkjgTmU90gwXQVURyIPesBO38fWeJ3oYBXKE0HWl4rc+Q7Y6EmB/id0A0Cc0gS+ xcRrH9WNRZawwZ3KRQRWTsQF+2xaZC4bVc/KD/JUqHqtEZrfl5o5bbHBpuFh/XrvlBr7 wZCHU8c6fc+M84IP59hTkfgDCEzvcKLmvTWHprVO0qfDnyadQOHFwEd0Xqxjx+zs94sh O8+t2jksZA4dKKRCntbNKrHqA2GTL5fgbYftKiiP3kvY++/UD87zhUfSItwIclE6pHhA zHRw== X-Gm-Message-State: AOAM532dtYPLJv2pAlQ2g+Cp4/9lFy6i8oUNqvjLX9tPM7CKWhjfsQmm 0l+U+tJngSEn0K0Fwme1mblqhA== X-Google-Smtp-Source: ABdhPJxNS3pgzDl97JFTDGbzH4ABBUnQVIs7N/AYeuFcDWEnn+XYab5nOhXpMtE23d76Im8PSkpEig== X-Received: by 2002:a63:84c3:: with SMTP id k186mr2705193pgd.394.1594876977998; Wed, 15 Jul 2020 22:22:57 -0700 (PDT) Received: from leoy-ThinkPad-X240s ([2600:3c01::f03c:91ff:fe8a:bb03]) by smtp.gmail.com with ESMTPSA id d18sm3584122pjz.11.2020.07.15.22.22.55 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Wed, 15 Jul 2020 22:22:57 -0700 (PDT) Date: Thu, 16 Jul 2020 13:22:59 +0800 From: Leo Yan To: Peter Zijlstra Cc: "Ahmed S. Darwish" , Thomas Gleixner , Will Deacon , John Ogness , "Sebastian A. Siewior" , LKML Subject: Re: [PATCH] time/sched_clock: Use raw_read_seqcount_latch() Message-ID: <20200716052259.GA4660@leoy-ThinkPad-X240s> References: <20200715095220.GH10769@hirez.programming.kicks-ass.net> <20200715115901.515956-1-a.darwish@linutronix.de> <20200715152926.GA16686@leoy-ThinkPad-X240s> <20200715155850.GL10769@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200715155850.GL10769@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Peter, Ahemd, On Wed, Jul 15, 2020 at 05:58:50PM +0200, Peter Zijlstra wrote: [...] > > > diff --git a/kernel/time/sched_clock.c b/kernel/time/sched_clock.c > > > index fa3f800d7d76..ea007928d681 100644 > > > --- a/kernel/time/sched_clock.c > > > +++ b/kernel/time/sched_clock.c > > > @@ -100,7 +100,7 @@ unsigned long long notrace sched_clock(void) > > > struct clock_read_data *rd; > > > > > > do { > > > - seq = raw_read_seqcount(&cd.seq); > > > + seq = raw_read_seqcount_latch(&cd.seq); > > > > Understand this is doing the same thing with __ktime_get_fast_ns() and > > I saw Peter acked to make change for this. > > > > Just want to confirm, since this patch introduces conflict with the > > patch set "arm64: perf: Proper cap_user_time* support" [1], I should > > rebase the patch set on top of this patch, right? > > Or rebase this patch on top of yours and include it, either way. Have rebased this patch and included it in the patch set v3 for "arm64: perf: Proper cap_user_time* support" [1]. Thanks! Leo [1] https://lore.kernel.org/linux-arm-kernel/20200716051130.4359-3-leo.yan@linaro.org/T/#u