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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 AE940C4332E for ; Thu, 19 Mar 2020 19:00:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7E2D32072C for ; Thu, 19 Mar 2020 19:00:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Wuji1qBo" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727188AbgCSTAq (ORCPT ); Thu, 19 Mar 2020 15:00:46 -0400 Received: from us-smtp-delivery-74.mimecast.com ([63.128.21.74]:54281 "EHLO us-smtp-delivery-74.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726589AbgCSTAq (ORCPT ); Thu, 19 Mar 2020 15:00:46 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1584644444; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=1t0CDXQGrkOTO7FpbdWrJYK+C3q0cC+jstTgkRHjIMg=; b=Wuji1qBoLapCm81NjNW3KKqXvE/fufBXdh+ZbEsujjgH5gAhfLN67J/N6rQWMALR4Jrd10 UA2DxylbSMhoVeY8ILJJeAW59PL1VYfuQOjzhGE9pvrAhEm8rqwUmmLpetQbMIW9T1V4Iq O1mne7bhLuvdXEXG72/R4miYkt0kBMU= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-340-OD2bujDXMLe31JPoO6ISew-1; Thu, 19 Mar 2020 15:00:40 -0400 X-MC-Unique: OD2bujDXMLe31JPoO6ISew-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4E6D218FE868; Thu, 19 Mar 2020 19:00:38 +0000 (UTC) Received: from llong.remote.csb (ovpn-113-139.rdu2.redhat.com [10.10.113.139]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6CE0F6EFAB; Thu, 19 Mar 2020 19:00:36 +0000 (UTC) Subject: Re: Hard lockups due to "tick/common: Make tick_periodic() check for missing ticks" To: Qian Cai , Thomas Gleixner , Stephen Rothwell Cc: "Joel Fernandes (Google)" , "Paul E. McKenney" , rcu@vger.kernel.org, LKML , Peter Zijlstra , Will Deacon , Ingo Molnar , Frederic Weisbecker References: <11BEA1A5-2E93-4E01-A05C-A6BA73A74CEB@lca.pw> From: Waiman Long Organization: Red Hat Message-ID: <218eed57-27c8-12c0-6f5f-111874798c21@redhat.com> Date: Thu, 19 Mar 2020 15:00:35 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <11BEA1A5-2E93-4E01-A05C-A6BA73A74CEB@lca.pw> Content-Type: text/plain; charset=utf-8 Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Content-Transfer-Encoding: quoted-printable Sender: rcu-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org On 3/19/20 9:58 AM, Qian Cai wrote: > >> On Mar 6, 2020, at 10:33 PM, Qian Cai wrote: >> >> >> >>> On Mar 5, 2020, at 11:06 PM, Qian Cai wrote: >>> >> Using this config, >> >>> https://raw.githubusercontent.com/cailca/linux-mm/master/x86.config >> Reverted the linux-next commit d441dceb5dce (=E2=80=9Ctick/common: Mak= e tick_periodic() check for missing ticks=E2=80=9D) >> fixed the lockup that could easily happen during boot. > > Thomas or Stephen, can you back out this patch from linux-next while Wa= iman is getting to the bottom of it? > I can still reproduce it as today. I am fine for reverting the patch for now. I am still having some trouble reproducing it and I have other tasks to work on right now. I will get to the bottom of it and resubmit a new patch later on. Cheers, Longman