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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B1C54EB64D9 for ; Thu, 15 Jun 2023 12:55:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239345AbjFOMzw (ORCPT ); Thu, 15 Jun 2023 08:55:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51306 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238426AbjFOMzs (ORCPT ); Thu, 15 Jun 2023 08:55:48 -0400 X-Greylist: delayed 2087 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Thu, 15 Jun 2023 05:55:47 PDT Received: from mx.treblig.org (unknown [IPv6:2a00:1098:5b::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 14A3C1BC9 for ; Thu, 15 Jun 2023 05:55:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=treblig.org ; s=bytemarkmx; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID :Subject:Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID :Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To: Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe :List-Post:List-Owner:List-Archive; bh=GE+Tl63UN/bjw5brENYW6CUw4m+KlAeFUuic6M+A4KQ=; b=Zzqm9rAYDbhknznnSjOJWcljLf wp2WwiWtx9bk+Pe1ezTsZgJy8ZRdllWKm+6uR1DVrF1/fVzBk3EQPQsRL0x75BaBSKx72TVR+kcwz Tjh90buA+Y2Z60lDJBQSnGEp3pnLQMqwP1be4CG6zfZvpcnqsk/k+gfXPCcqit0NPfLIeU1p2QaGq +7AdP0x+Y3Gb9KkXs4buEyQijNQ2cWxZxZf0zVKZ9hNAY3b80Jtyk2x9bsZWg9ZSgqdAvq72ArhqQ Nk+tuzJa87jDtF7bef8E6eGMAx0zZJvXG8beVYJHbG/UNLK9pxSAlsaZ0s6wDOZp2UmT9N+Q3UX0d 3H8z2+5A==; Received: from dg by mx.treblig.org with local (Exim 4.94.2) (envelope-from ) id 1q9ly6-00EGxW-9x; Thu, 15 Jun 2023 12:20:50 +0000 Date: Thu, 15 Jun 2023 12:20:50 +0000 From: "Dr. David Alan Gilbert" To: "Richard W.M. Jones" Cc: YiFei Zhu , dev@aaront.org, linux-kernel@vger.kernel.org, peterz@infradead.org, zhuyifei1999@gmail.com Subject: Re: printk.time causes rare kernel boot hangs Message-ID: References: <20230614112625.GN7912@redhat.com> <20230615110429.2839058-1-zhuyifei@google.com> <20230615113108.GN7636@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20230615113108.GN7636@redhat.com> X-Chocolate: 70 percent or better cocoa solids preferably X-Operating-System: Linux/5.10.0-21-amd64 (x86_64) X-Uptime: 12:05:57 up 87 days, 22:40, 1 user, load average: 0.10, 0.04, 0.01 User-Agent: Mutt/2.0.5 (2021-01-21) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Richard W.M. Jones (rjones@redhat.com) wrote: > On Thu, Jun 15, 2023 at 11:04:29AM +0000, YiFei Zhu wrote: > > see if you can send a alt-sysrq-w to show stacks of > > blocked tasks. > > I guess this is a virtual console thing? I have to boot this hundreds > of times with a serial console to even get to the bug, so it's tricky. If you open a monitor device you should be able to do things to the qemu after you detect the hang; and then I think a : sendkey alt-sysrq-w on HMP should do it. However, some other thoughts: a) You could try taking a dump and then importing it into crash rather than using gdb; both ways are touchy, but that does mean you could give the dump to someone else who can't trigger the bug. b) You could try giving your kernel to someone who can't trigger it; if they can trigger it on their host with your kernel that would suggest something is different in your build environment of your kernel (e.g. compiler version or flags) rather than the host kernel. Dave > Rich. > > -- > Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones > Read my programming and virtualization blog: http://rwmj.wordpress.com > virt-builder quickly builds VMs from scratch > http://libguestfs.org/virt-builder.1.html > -- -----Open up your eyes, open up your mind, open up your code ------- / Dr. David Alan Gilbert | Running GNU/Linux | Happy \ \ dave @ treblig.org | | In Hex / \ _________________________|_____ http://www.treblig.org |_______/