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 X-Spam-Level: X-Spam-Status: No, score=-7.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 171B3C433E0 for ; Fri, 26 Mar 2021 14:46:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D8CF361A18 for ; Fri, 26 Mar 2021 14:46:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230138AbhCZOqC (ORCPT ); Fri, 26 Mar 2021 10:46:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54950 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230142AbhCZOpa (ORCPT ); Fri, 26 Mar 2021 10:45:30 -0400 Received: from hr2.samba.org (hr2.samba.org [IPv6:2a01:4f8:192:486::2:0]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 16E98C0613AA; Fri, 26 Mar 2021 07:45:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=samba.org; s=42; h=Date:Message-ID:Cc:To:From; bh=mtNIqPG9Q1dGrTRGe+RN+2nCiKVa40ParN2yl85CZag=; b=xMWEHeL0j0R9MXCbrX2fCj04af +xm+YVzki5Mb5SP/Xj8sJTfu8Ay3RxevoIKsYLEDMMj595h5yFFHX6awnGFK6+LEtBx3dm1ZMwkyq 4kGujtP10e1fpcqOxY/OfZdOGgo497qcYYQSSaSz4o0rYOvoC9jUM+BfpLpq7sY9sUjWf6gi17/Fc supOCeU/oVVpTD15UEsd8DlbHKgzmKBaBty3H206WVp8GWDYNyIpbNNA8AL419GHsXcttdVZNmbiY S8sEZ2OqJFc9FWAC2Sn8Ie4UJ+ZP/E5/ryTR78nrVFrmIw1GKEAQyKZ+1SOSFEMFQ1wRr0det6yxw fe9CJH+pFMmGFxU7DLnLhPWngALAihhH9D+RqlrMNhj/so5ySVa84ZOCQ5z/ayN8HjTn1bOcpAqxc O/oeaKXWs2RFj/W7sw6tCh+WvLcX3XOFGrbkJHzw4dCpiiUjByFB0aiXjgPLIym3rFRoKv1GbqGp9 +k5cSjJn4p7TB0sEeSp/4cnL; Received: from [127.0.0.2] (localhost [127.0.0.1]) by hr2.samba.org with esmtpsa (TLS1.3:ECDHE_RSA_CHACHA20_POLY1305:256) (Exim) id 1lPniK-00039z-F3; Fri, 26 Mar 2021 14:45:28 +0000 Subject: Re: [PATCH 0/6] Allow signals for IO threads From: Stefan Metzmacher To: Jens Axboe , io-uring@vger.kernel.org Cc: torvalds@linux-foundation.org, ebiederm@xmission.com, oleg@redhat.com, linux-kernel@vger.kernel.org References: <20210326003928.978750-1-axboe@kernel.dk> <8efd9977-003b-be65-8ae2-4b04d8dd1224@samba.org> <0c91d9e7-82cd-bec2-19ae-cc592ec757c6@kernel.dk> <66fa3cfc-4161-76fe-272e-160097f32a53@kernel.dk> <67a83ad5-1a94-39e5-34c7-6b2192eb7edb@samba.org> Message-ID: Date: Fri, 26 Mar 2021 15:45:25 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: <67a83ad5-1a94-39e5-34c7-6b2192eb7edb@samba.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 26.03.21 um 15:43 schrieb Stefan Metzmacher: > Am 26.03.21 um 15:38 schrieb Jens Axboe: >> On 3/26/21 7:59 AM, Jens Axboe wrote: >>> On 3/26/21 7:54 AM, Jens Axboe wrote: >>>>> The KILL after STOP deadlock still exists. >>>> >>>> In which tree? Sounds like you're still on the old one with that >>>> incremental you sent, which wasn't complete. >>>> >>>>> Does io_wq_manager() exits without cleaning up on SIGKILL? >>>> >>>> No, it should kill up in all cases. I'll try your stop + kill, I just >>>> tested both of them separately and didn't observe anything. I also ran >>>> your io_uring-cp example (and found a bug in the example, fixed and >>>> pushed), fwiw. >>> >>> I can reproduce this one! I'll take a closer look. >> >> OK, that one is actually pretty straight forward - we rely on cleaning >> up on exit, but for fatal cases, get_signal() will call do_exit() for us >> and never return. So we might need a special case in there to deal with >> that, or some other way of ensuring that fatal signal gets processed >> correctly for IO threads. > > And if (fatal_signal_pending(current)) doesn't prevent get_signal() from being called? Ah, we're still in the first get_signal() from SIGSTOP, correct? metze