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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 7035FC43219 for ; Fri, 3 May 2019 00:00:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 44BC32070B for ; Fri, 3 May 2019 00:00:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726327AbfECAAq (ORCPT ); Thu, 2 May 2019 20:00:46 -0400 Received: from mail-qt1-f195.google.com ([209.85.160.195]:42828 "EHLO mail-qt1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726053AbfECAAq (ORCPT ); Thu, 2 May 2019 20:00:46 -0400 Received: by mail-qt1-f195.google.com with SMTP id p20so4818905qtc.9 for ; Thu, 02 May 2019 17:00:45 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:subject:from:to:cc:date:in-reply-to :references:mime-version:content-transfer-encoding; bh=pPqKk1Nce9ulB47hrGMNOsWZDkTL1qhAM3SCFqkBmyg=; b=iIHP4ripfobNY9t2B9kaUxnPAmRH0HpTLVF6XctyYjvziP6Wqf1eJC5jI9X8n2kETM dlryxKTYPX3zzCBIsMQrQgKx09RX6lOBFtRqDtohNQLO2BNOqma+8bRhrGDkbx5EC1eB gLnCqa69UsU6bN5ZVUwdoBHNPRx95yppcrt90sjBZmZypK56nqFpsnLQSPUEQcis2qCg X4vL0jVmTgugr5Ir17bn9hSc1/7SbeAhh5PeKYcGOpl9aGSi1oz8jvScpdTwsXpGKeuG y48r7AV25eLiJoCLSQAL/mMyfx4bTP7yjEQYVXalxaJyWRxSEitYWLHWzRjv9bZdSdZi kmFg== X-Gm-Message-State: APjAAAUDl/IwdLUXxl014Glu3BLStMz7jgw4nm1z8EZ2HsyJ0uAxfzi0 eWKzJ8TN15tlYAxy3ADuWD8nOA== X-Google-Smtp-Source: APXvYqzAzN3fqk+Sn0S7PSCnrWs48hQdYqyQUYcdLogPdX2Kvo9EOJ9LoB1Ax20VDtUU5rkOZhdoDQ== X-Received: by 2002:ac8:1a41:: with SMTP id q1mr5928878qtk.185.1556841644635; Thu, 02 May 2019 17:00:44 -0700 (PDT) Received: from 2600-6c64-4e80-00f1-336a-6920-3806-8b87.dhcp6.chtrptr.net (2600-6c64-4e80-00f1-336a-6920-3806-8b87.dhcp6.chtrptr.net. [2600:6c64:4e80:f1:336a:6920:3806:8b87]) by smtp.gmail.com with ESMTPSA id o55sm553683qtj.14.2019.05.02.17.00.43 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 02 May 2019 17:00:43 -0700 (PDT) Message-ID: Subject: Re: [PATCH 2/2] RFC: soft/hardlookup: taint kernel From: Laurence Oberman To: Daniel Vetter , Intel Graphics Development Cc: LKML , Daniel Vetter , Thomas Gleixner , Ingo Molnar , Peter Zijlstra , Valdis Kletnieks , Vincent Whitchurch , Don Zickus , Andrew Morton , Sergey Senozhatsky , Sinan Kaya Date: Thu, 02 May 2019 20:00:42 -0400 In-Reply-To: <20190502194208.3535-2-daniel.vetter@ffwll.ch> References: <20190502194208.3535-1-daniel.vetter@ffwll.ch> <20190502194208.3535-2-daniel.vetter@ffwll.ch> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5 (3.28.5-2.el7) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2019-05-02 at 21:42 +0200, Daniel Vetter wrote: > There's the soft/hardlookup_panic sysctls, but that's a bit an > extreme > measure. As a fallback taint at least the machine. > > Our CI uses this to decide when a reboot is necessary, plus to figure > out whether the kernel is still happy. > > Signed-off-by: Daniel Vetter > Cc: Thomas Gleixner > Cc: Ingo Molnar > Cc: Peter Zijlstra > Cc: Valdis Kletnieks > Cc: Laurence Oberman > Cc: Vincent Whitchurch > Cc: Don Zickus > Cc: Andrew Morton > Cc: Sergey Senozhatsky > Cc: Sinan Kaya > Cc: Daniel Vetter > --- > kernel/watchdog.c | 2 ++ > kernel/watchdog_hld.c | 2 ++ > 2 files changed, 4 insertions(+) > > diff --git a/kernel/watchdog.c b/kernel/watchdog.c > index 6a5787233113..de7a60503517 100644 > --- a/kernel/watchdog.c > +++ b/kernel/watchdog.c > @@ -469,6 +469,8 @@ static enum hrtimer_restart > watchdog_timer_fn(struct hrtimer *hrtimer) > add_taint(TAINT_SOFTLOCKUP, LOCKDEP_STILL_OK); > if (softlockup_panic) > panic("softlockup: hung tasks"); > + else > + add_taint(TAINT_WARN, LOCKDEP_STILL_OK); > __this_cpu_write(soft_watchdog_warn, true); > } else > __this_cpu_write(soft_watchdog_warn, false); > diff --git a/kernel/watchdog_hld.c b/kernel/watchdog_hld.c > index 247bf0b1582c..cce46cf75d76 100644 > --- a/kernel/watchdog_hld.c > +++ b/kernel/watchdog_hld.c > @@ -154,6 +154,8 @@ static void watchdog_overflow_callback(struct > perf_event *event, > > if (hardlockup_panic) > nmi_panic(regs, "Hard LOCKUP"); > + else > + add_taint(TAINT_WARN, LOCKDEP_STILL_OK); > > __this_cpu_write(hard_watchdog_warn, true); > return; This looks OK to me, could be useful to know we would have triggered had the flags been set. Reviewed-by: Laurence Oberman