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=-2.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_NEOMUTT 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 249B3C4646C for ; Tue, 25 Jun 2019 03:03:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 02F8920663 for ; Tue, 25 Jun 2019 03:03:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730679AbfFYDDv (ORCPT ); Mon, 24 Jun 2019 23:03:51 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58510 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729502AbfFYDDu (ORCPT ); Mon, 24 Jun 2019 23:03:50 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 177533082133; Tue, 25 Jun 2019 03:03:49 +0000 (UTC) Received: from treble (ovpn-126-66.rdu2.redhat.com [10.10.126.66]) by smtp.corp.redhat.com (Postfix) with ESMTPS id DC3C119722; Tue, 25 Jun 2019 03:03:47 +0000 (UTC) Date: Mon, 24 Jun 2019 22:03:45 -0500 From: Josh Poimboeuf To: Linus Torvalds Cc: Chris Wilson , Linux List Kernel Mailing , Steven Rostedt , Thomas Gleixner Subject: Re: NMI hardlock stacktrace deadlock [was Re: Linux 5.2-rc5] Message-ID: <20190625030345.dwbydi2w67mpp4zq@treble> References: <156094799629.21217.4574572565333265288@skylake-alporthouse-com> <156097197830.664.13418742301997062555@skylake-alporthouse-com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180716 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.42]); Tue, 25 Jun 2019 03:03:50 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 19, 2019 at 01:42:53PM -0700, Linus Torvalds wrote: > On Wed, Jun 19, 2019 at 12:19 PM Chris Wilson wrote: > > > > > Do you have the oops itself at all? > > > > An example at > > https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6310/fi-kbl-x1275/dmesg0.log > > https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6310/fi-kbl-x1275/boot0.log > > > > The bug causing the oops is clearly a driver problem. The rc5 fallout > > just seems to be because of some shrinker changes affecting some object > > reaping that were unfortunately still active. What perturbed the CI > > team was the machine failed to panic & reboot. > > Hmm. It's hard to guess at the cause of that. The oopses themselves > don't look like they are happening in any particularly bad context, so > all the normal reboot-on-oops etc stuff _should_ work. Looking at the dmesg, panic_on_oops doesn't seem to be enabled: it went through the rewind_stack_do_exit() path instead of the panic() path. So the system is apparently not configured to reboot on oops. So I'd say the hang was presumably caused by a lock held by the oopsing code. So it looks normal to me, other than the original oops. -- Josh