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 59AF6C433EF for ; Sun, 26 Jun 2022 00:19:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233622AbiFZATi (ORCPT ); Sat, 25 Jun 2022 20:19:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46276 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229603AbiFZATh (ORCPT ); Sat, 25 Jun 2022 20:19:37 -0400 Received: from out02.mta.xmission.com (out02.mta.xmission.com [166.70.13.232]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C2E7013E8F for ; Sat, 25 Jun 2022 17:19:36 -0700 (PDT) Received: from in01.mta.xmission.com ([166.70.13.51]:41856) by out02.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1o5Fzz-009E2B-H2; Sat, 25 Jun 2022 18:19:35 -0600 Received: from ip68-227-174-4.om.om.cox.net ([68.227.174.4]:57626 helo=email.froward.int.ebiederm.org.xmission.com) by in01.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1o5Fzy-00AYHt-KI; Sat, 25 Jun 2022 18:19:35 -0600 From: "Eric W. Biederman" To: Linus Torvalds Cc: Christian Brauner , Tejun Heo , Petr Mladek , Lai Jiangshan , Michal Hocko , Linux Kernel Mailing List , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Andrew Morton , Oleg Nesterov References: <20220622140853.31383-1-pmladek@suse.com> <874k0863x8.fsf@email.froward.int.ebiederm.org> <87pmiw1fy6.fsf@email.froward.int.ebiederm.org> Date: Sat, 25 Jun 2022 19:19:27 -0500 In-Reply-To: (Linus Torvalds's message of "Sat, 25 Jun 2022 16:48:38 -0700") Message-ID: <87y1xkwa28.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 X-XM-SPF: eid=1o5Fzy-00AYHt-KI;;;mid=<87y1xkwa28.fsf@email.froward.int.ebiederm.org>;;;hst=in01.mta.xmission.com;;;ip=68.227.174.4;;;frm=ebiederm@xmission.com;;;spf=softfail X-XM-AID: U2FsdGVkX1/D80Oi4qTinv1YmPEUUSX8Os0cPZfAqnk= X-SA-Exim-Connect-IP: 68.227.174.4 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: Re: re. Spurious wakeup on a newly created kthread X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Linus Torvalds writes: > Anyway, the whole "don't wake up thread until it's all done" is a > separate and independent issue from the "odd use of kthreadd" issue. Yes. "don't wake up a kthread until it's all done" is a much easier change that will simplify things tremendously. Further it is necessary for Peter Zijlstra's rewrite of the kernel freezer. As anything that isn't a special stop state (which TASK_UNINTERRUPTIBLE is not) will receive a spurious wake up on when thawed out. Eric