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=-6.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 50AACC433ED for ; Mon, 17 May 2021 23:55:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 29A796108C for ; Mon, 17 May 2021 23:55:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344682AbhEQX4o (ORCPT ); Mon, 17 May 2021 19:56:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55634 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239438AbhEQX4l (ORCPT ); Mon, 17 May 2021 19:56:41 -0400 Received: from mail-pg1-x52f.google.com (mail-pg1-x52f.google.com [IPv6:2607:f8b0:4864:20::52f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5A22AC061573 for ; Mon, 17 May 2021 16:55:23 -0700 (PDT) Received: by mail-pg1-x52f.google.com with SMTP id 6so5731751pgk.5 for ; Mon, 17 May 2021 16:55:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=Dt/9En1bGh9mqV5EDahzJAJYX6uZITBcCbOiK+du0JQ=; b=REtaxFuOq2C7rrWmKN8QPNMb56kHx90r/ZLUD5LtniukPNpoviGx1VVxzCMPE8FXpu cB/PqjB02JKjhWZTFMl/lF/b4tZK39vXd+kLpH+jprVFn9iLAhG0VhsifsZtcIjT8jbR xwJtd+AnwnzUHHj8pSaxUFgPdF4U1P7Ep45y8= 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; bh=Dt/9En1bGh9mqV5EDahzJAJYX6uZITBcCbOiK+du0JQ=; b=mENPWdubYvN87mVpsTErw0gbaGG7bqTZowd/VnkT/TjGk3yGjS5I1KsRm2WaE//sQz LfJOZU0Gou7/r3IhU+1UAIcQmK+JlJ+S/1OiNSNGmoqLvYCBXQlLsZzSO1ppCZWoWdxg 2wNQt56fQJ0tVjbzxnZKLStd5gMQnxECoAr6R3i6M3B0Yjra/C0UCk+3b9+b6vLI3gdO lX12NZNds/iZG30612J/dHYusukqa4whFh5xtcOlCZmGgoX+xKACB5nIzC8/nIrsk/6p ag4VFWjY8FFsmj5+jK/+I0iiQHZnJOR5/9CkaNNoppB1GnMQA0vn+/YmUi8SV99AQSDl DWMA== X-Gm-Message-State: AOAM532iMnGTN7B+/kWCufPU51otO01VVmPNxbBOnc/KeWVx21Smu09Y OYz5KyUpacGs2mBk2Dg9Yik5Fw== X-Google-Smtp-Source: ABdhPJzjWUTAiFLfgQZeKKCkY0XQYoEwCLqRSutkBu75r4AjWSrcVDD7G8M3LXAo9+FSKhhLEaVj7g== X-Received: by 2002:a63:79c5:: with SMTP id u188mr2084699pgc.198.1621295722925; Mon, 17 May 2021 16:55:22 -0700 (PDT) Received: from google.com ([2409:10:2e40:5100:1f25:dd29:abb6:257a]) by smtp.gmail.com with ESMTPSA id 11sm6015257pfh.182.2021.05.17.16.55.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 17 May 2021 16:55:22 -0700 (PDT) Date: Tue, 18 May 2021 08:55:17 +0900 From: Sergey Senozhatsky To: Petr Mladek Cc: Greg Kroah-Hartman , linux-kernel@vger.kernel.org, stable@vger.kernel.org, Ingo Molnar , Laurence Oberman , Michal Hocko , Peter Zijlstra , Thomas Gleixner , Vincent Whitchurch , Andrew Morton , Linus Torvalds , Sergey Senozhatsky , Sasha Levin Subject: Re: [PATCH 5.12 123/363] watchdog: cleanup handling of false positives Message-ID: References: <20210517140302.508966430@linuxfoundation.org> <20210517140306.783130885@linuxfoundation.org> 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-kernel@vger.kernel.org On (21/05/17 16:30), Petr Mladek wrote: > On Mon 2021-05-17 15:59:49, Greg Kroah-Hartman wrote: > > From: Petr Mladek > > > > [ Upstream commit 9bf3bc949f8aeefeacea4b1198db833b722a8e27 ] > > > > Commit d6ad3e286d2c ("softlockup: Add sched_clock_tick() to avoid kernel > > warning on kgdb resume") introduced touch_softlockup_watchdog_sync(). > > [...] > > > Make the code more straightforward: > > > > 1. Always call kvm_check_and_clear_guest_paused() at the very > > beginning to handle PVCLOCK_GUEST_STOPPED. It touches the watchdog > > when the quest did sleep. > > > > 2. Handle the situation when the watchdog has been touched > > (SOFTLOCKUP_DELAY_REPORT is set). > > > > Call sched_clock_tick() when touch_*sync() variant was used. It makes > > sure that the timestamp will be up to date even when it has been > > touched in atomic context or quest did sleep. > > > > As a result, kvm_check_and_clear_guest_paused() is called on a single > > location. And the right timestamp is always set when returning from the > > timer callback. > > > > Link: https://lkml.kernel.org/r/20210311122130.6788-7-pmladek@suse.com > > Please, remove this patch from the stable backport. It might > cause false softlockup reports, see Oh, I didn't know about the stable backport. Thank you for taking care of it.