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 A04C0C88CB2 for ; Mon, 12 Jun 2023 17:11:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230302AbjFLRLb convert rfc822-to-8bit (ORCPT ); Mon, 12 Jun 2023 13:11:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54934 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231252AbjFLRLb (ORCPT ); Mon, 12 Jun 2023 13:11:31 -0400 Received: from out02.mta.xmission.com (out02.mta.xmission.com [166.70.13.232]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 99B06113; Mon, 12 Jun 2023 10:11:30 -0700 (PDT) Received: from in02.mta.xmission.com ([166.70.13.52]:56964) by out02.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1q8l4i-008G1Y-7Y; Mon, 12 Jun 2023 11:11:28 -0600 Received: from ip68-110-29-46.om.om.cox.net ([68.110.29.46]:35692 helo=email.froward.int.ebiederm.org.xmission.com) by in02.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1q8l4h-00GGD8-4b; Mon, 12 Jun 2023 11:11:27 -0600 From: "Eric W. Biederman" To: Linus Torvalds Cc: Jens Axboe , "Darrick J. Wong" , Dave Chinner , Zorro Lang , linux-xfs@vger.kernel.org, Mike Christie , "Michael S. Tsirkin" , linux-kernel@vger.kernel.org References: <20230611124836.whfktwaumnefm5z5@zlang-mailbox> <20230612015145.GA11441@frogsfrogsfrogs> <20230612153629.GA11427@frogsfrogsfrogs> <13d9e4f2-17c5-0709-0cc0-6f92bfe9f30d@kernel.dk> <212a190c-f81e-2876-cf14-6d1e37d47192@kernel.dk> Date: Mon, 12 Jun 2023 12:11:19 -0500 In-Reply-To: (Linus Torvalds's message of "Mon, 12 Jun 2023 09:57:51 -0700") Message-ID: <87wn08ppvs.fsf@email.froward.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT X-XM-SPF: eid=1q8l4h-00GGD8-4b;;;mid=<87wn08ppvs.fsf@email.froward.int.ebiederm.org>;;;hst=in02.mta.xmission.com;;;ip=68.110.29.46;;;frm=ebiederm@xmission.com;;;spf=pass X-XM-AID: U2FsdGVkX19EY7Ho9kfWEUAJ7nVOKAACcXVbaQOg1IQ= X-SA-Exim-Connect-IP: 68.110.29.46 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: Re: [6.5-rc5 regression] core dump hangs (was Re: [Bug report] fstests generic/051 (on xfs) hang on latest linux v6.5-rc5+) X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org Linus Torvalds writes: > On Mon, Jun 12, 2023 at 9:45 AM Jens Axboe wrote: >> >> You snipped the suspicion in my reply on why that exists, to avoid >> io_wq_worker_sleeping() triggering. > > I'm not seeing why triggering io_wq_worker_sleeping() should even be a > problem in the first place. > > I suspect that is entirely historical too, and has to do with how it > used to do that > > struct io_worker *worker = kthread_data(tsk); > struct io_wqe *wqe = worker->wqe; > > back in the bad old days of kthreads. > > But yeah, I don't know that code. If it is a problem it looks like the thread shutdown can clear "worker->flags & IO_WORKER_F_UP" rather than "current->flags & PF_IO_WORKER". I don't see how it makes sense for the load balancing logic for a per-process thread pool to be running at that point. Eric