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 DC5E9C433F5 for ; Thu, 3 Mar 2022 14:37:15 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 195198D0002; Thu, 3 Mar 2022 09:37:15 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 11CA58D0001; Thu, 3 Mar 2022 09:37:15 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 00DE48D0002; Thu, 3 Mar 2022 09:37:14 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.a.hostedemail.com [64.99.140.24]) by kanga.kvack.org (Postfix) with ESMTP id E6AD58D0001 for ; Thu, 3 Mar 2022 09:37:14 -0500 (EST) Received: from smtpin09.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id B40FF672 for ; Thu, 3 Mar 2022 14:37:14 +0000 (UTC) X-FDA: 79203327588.09.C217AF1 Received: from outgoing.mit.edu (outgoing-auth-1.mit.edu [18.9.28.11]) by imf29.hostedemail.com (Postfix) with ESMTP id 32A57120012 for ; Thu, 3 Mar 2022 14:37:13 +0000 (UTC) Received: from cwcc.thunk.org (pool-108-7-220-252.bstnma.fios.verizon.net [108.7.220.252]) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id 223EaQU4027851 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 3 Mar 2022 09:36:27 -0500 Received: by cwcc.thunk.org (Postfix, from userid 15806) id F15C115C0038; Thu, 3 Mar 2022 09:36:25 -0500 (EST) Date: Thu, 3 Mar 2022 09:36:25 -0500 From: "Theodore Ts'o" To: Byungchul Park 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: 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: <1646285013-3934-1-git-send-email-byungchul.park@lge.com> X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 32A57120012 X-Stat-Signature: md7fbtnwpyp1e5qtyhikx11pb4ijyrw4 Authentication-Results: imf29.hostedemail.com; dkim=none; spf=none (imf29.hostedemail.com: domain of tytso@mit.edu has no SPF policy when checking 18.9.28.11) smtp.mailfrom=tytso@mit.edu; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=mit.edu (policy=none) X-HE-Tag: 1646318233-554610 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 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? - Ted