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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id E5EFDC433F5 for ; Fri, 4 Mar 2022 03:50:30 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6CE718D0002; Thu, 3 Mar 2022 22:50:30 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 67E8D8D0001; Thu, 3 Mar 2022 22:50:30 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 594E38D0002; Thu, 3 Mar 2022 22:50:30 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0209.hostedemail.com [216.40.44.209]) by kanga.kvack.org (Postfix) with ESMTP id 4C6D18D0001 for ; Thu, 3 Mar 2022 22:50:30 -0500 (EST) Received: from smtpin30.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 0A92A8249980 for ; Fri, 4 Mar 2022 03:50:30 +0000 (UTC) X-FDA: 79205326620.30.4A6FC33 Received: from lgeamrelo11.lge.com (lgeamrelo13.lge.com [156.147.23.53]) by imf04.hostedemail.com (Postfix) with ESMTP id B95DB4000F for ; Fri, 4 Mar 2022 03:50:27 +0000 (UTC) Received: from unknown (HELO lgeamrelo01.lge.com) (156.147.1.125) by 156.147.23.53 with ESMTP; 4 Mar 2022 12:20:25 +0900 X-Original-SENDERIP: 156.147.1.125 X-Original-MAILFROM: byungchul.park@lge.com Received: from unknown (HELO X58A-UD3R) (10.177.244.38) by 156.147.1.125 with ESMTP; 4 Mar 2022 12:20:24 +0900 X-Original-SENDERIP: 10.177.244.38 X-Original-MAILFROM: byungchul.park@lge.com Date: Fri, 4 Mar 2022 12:20:02 +0900 From: Byungchul Park To: Theodore Ts'o Cc: damien.lemoal@opensource.wdc.com, linux-ide@vger.kernel.org, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, torvalds@linux-foundation.org, mingo@redhat.com, linux-kernel@vger.kernel.org, peterz@infradead.org, will@kernel.org, tglx@linutronix.de, rostedt@goodmis.org, joel@joelfernandes.org, sashal@kernel.org, daniel.vetter@ffwll.ch, chris@chris-wilson.co.uk, duyuyang@gmail.com, johannes.berg@intel.com, tj@kernel.org, willy@infradead.org, david@fromorbit.com, amir73il@gmail.com, bfields@fieldses.org, gregkh@linuxfoundation.org, kernel-team@lge.com, linux-mm@kvack.org, akpm@linux-foundation.org, mhocko@kernel.org, minchan@kernel.org, hannes@cmpxchg.org, vdavydov.dev@gmail.com, sj@kernel.org, jglisse@redhat.com, dennis@kernel.org, cl@linux.com, penberg@kernel.org, rientjes@google.com, vbabka@suse.cz, ngupta@vflare.org, linux-block@vger.kernel.org, paolo.valente@linaro.org, josef@toxicpanda.com, linux-fsdevel@vger.kernel.org, viro@zeniv.linux.org.uk, jack@suse.cz, jack@suse.com, jlayton@kernel.org, dan.j.williams@intel.com, hch@infradead.org, djwong@kernel.org, dri-devel@lists.freedesktop.org, airlied@linux.ie, rodrigosiqueiramelo@gmail.com, melissa.srw@gmail.com, hamohammed.sa@gmail.com Subject: Re: Report 2 in ext4 and journal based on v5.17-rc1 Message-ID: <20220304032002.GD6112@X58A-UD3R> References: <1646285013-3934-1-git-send-email-byungchul.park@lge.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-Rspamd-Queue-Id: B95DB4000F X-Stat-Signature: 4bzhj77tyqy8ucbr8bseihrzi6a1a1ku X-Rspam-User: Authentication-Results: imf04.hostedemail.com; dkim=none; spf=pass (imf04.hostedemail.com: domain of byungchul.park@lge.com designates 156.147.23.53 as permitted sender) smtp.mailfrom=byungchul.park@lge.com; dmarc=none X-Rspamd-Server: rspam07 X-HE-Tag: 1646365827-139975 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Mar 03, 2022 at 09:36:25AM -0500, Theodore Ts'o wrote: > On Thu, Mar 03, 2022 at 02:23:33PM +0900, Byungchul Park wrote: > > I totally agree with you. *They aren't really locks but it's just waits > > and wakeups.* That's exactly why I decided to develop Dept. Dept is not > > interested in locks unlike Lockdep, but fouces on waits and wakeup > > sources itself. I think you get Dept wrong a lot. Please ask me more if > > you have things you doubt about Dept. > > So the question is this --- do you now understand why, even though > there is a circular dependency, nothing gets stalled in the > interactions between the two wait channels? I found a point that the two wait channels don't lead a deadlock in some cases thanks to Jan Kara. I will fix it so that Dept won't complain it. Thanks, Byungchul > > - Ted