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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3EDECC433EF for ; Thu, 21 Oct 2021 15:01:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 25A4260F9F for ; Thu, 21 Oct 2021 15:01:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230331AbhJUPEK (ORCPT ); Thu, 21 Oct 2021 11:04:10 -0400 Received: from smtp-out2.suse.de ([195.135.220.29]:33258 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229450AbhJUPEJ (ORCPT ); Thu, 21 Oct 2021 11:04:09 -0400 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id B6E681FDB6; Thu, 21 Oct 2021 15:01:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1634828512; h=from:from:reply-to: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=GP6CrJsowFn6A295uzld78nq0V0XLKgx7KI0Os/fPnY=; b=gAfz4/sndpuWdamoHWhcrwe7reywswCrtVBv4uE3RRXWe5guWl6sPeVK1CiRadP7rpYeok P5iBTS5IpDaqKXGAyCILYbO5qsTcId+LJsFy68By08Y5xxS6gEfvdJoPXUwBf2vQuUGvlH 6TLVUlodQBpjHekLw8s43oiZY/HccBc= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 71BF313AB0; Thu, 21 Oct 2021 15:01:52 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id yk05GeCAcWH4TAAAMHmgww (envelope-from ); Thu, 21 Oct 2021 15:01:52 +0000 Subject: Re: 5.14.9 aarch64 OOPS Workqueue: btrfs-delalloc btrfs_work_helper To: Chris Murphy Cc: Su Yue , Qu Wenruo , Qu Wenruo , Btrfs BTRFS References: <7de9iylb.fsf@damenly.su> <35owijrm.fsf@damenly.su> <2e18d933-a56e-198d-20c8-ab3038d3f390@suse.com> From: Nikolay Borisov Message-ID: <3c1ead76-e321-a3c1-755c-288ddd5fbeeb@suse.com> Date: Thu, 21 Oct 2021 18:01:51 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 21.10.21 г. 17:55, Chris Murphy wrote: > On Thu, Oct 21, 2021 at 10:51 AM Nikolay Borisov wrote: >> >> >> >> On 21.10.21 г. 17:48, Chris Murphy wrote: >>> [ 287.139760] Call trace: >>> [ 287.141784] submit_compressed_extents+0x38/0x3d0 >>> [ 287.145620] async_cow_submit+0x50/0xd0 >>> [ 287.148801] run_ordered_work+0xc8/0x280 >>> [ 287.152005] btrfs_work_helper+0x98/0x250 >>> [ 287.155450] process_one_work+0x1f0/0x4ac >>> [ 287.161577] worker_thread+0x188/0x504 >>> [ 287.167461] kthread+0x110/0x114 >>> [ 287.172872] ret_from_fork+0x10/0x18 >>> [ 287.178558] Code: a9056bf9 f8428437 f9401400 d108c2fa (f9400356) >>> [ 287.186268] ---[ end trace 41ec405ced3786b6 ]--- >>> [61620.974232] audit: audit_backlog=2976 > audit_backlog_limit=64 >>> [61620.978698] audit: audit_lost=1 audit_rate_limit=0 audit_backlog_limit=64 >>> >>> >>> So it's at least 17 hours later since the splat. Is it worth sysrq+c >>> now this long after? Or should I set it up like Nikolay suggests with >>> kernel.panic_on_warn = 1? Maybe I should also put /var/crash on XFS to >>> avoid problems dumping the kernel core file? >> >> Doing sysrq+c would not have yileded any useful information it was a red >> herring. In order to have actionable information the core dump needs to >> be initiated from offending context, this means either having a BUG_ON >> or a WARN which triggers the panic. > > > OK so I'll put /var/crash on XFS and set kernel.panic_on_warn = 1 and > try to reproduce the problem; and hopefully that triggers kdump. Just to be clear, when you initiate a crash with sysrq+c does it capture a crashdump? That's the basic test that needs to pass in order to ensure kdump works as expected. > >