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 091E3C43462 for ; Thu, 1 Apr 2021 18:17:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D7BE960241 for ; Thu, 1 Apr 2021 18:17:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239011AbhDASPN (ORCPT ); Thu, 1 Apr 2021 14:15:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60810 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236065AbhDAR5R (ORCPT ); Thu, 1 Apr 2021 13:57:17 -0400 Received: from hr2.samba.org (hr2.samba.org [IPv6:2a01:4f8:192:486::2:0]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 60FFBC0D9426; Thu, 1 Apr 2021 07:53:23 -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=8jYVTSHcDUfHY7lSnRvxzqvV+XEOiioVeMCNkU5pL/U=; b=gmeqKFSfEmZMR4ikxGpeC9sR6z HstPDGcPczEeSWVvfeQryWdLv5R0S8Lvi/AS+peqlhACr6i8pQZvrjTYs8gXY5UGXcNAh11PcNS9h L4rOw1MMvCOPtEg7gPMyfgcuEIKpI+SsdA1FnVDympI0txP4z1iGSHrA3YpHoJjq1YCuDNAu04YSN GQ2RP1MO7lwug85uFQi7RCikLv5eL9DW8VmzFnPV9DVPXKQnQ68TODydm0GPBcNefySbrIi6JVebG dXpnluVTE8W71WJ5ORgMnuBsJlp3ot2ldpSPuXaP93I+7leTSMfTBM6j4kFtCrrlSJXRUyOiHxedD qhfjLZo0vOT54tB7E4WWwA/g60y9moxBetQSLwZklwq3ny8AgUd95GtqLA39O29qHkdA3J949aHsx TvowkICdfdpaqLCdV/7V2UtVaXPzLpt+qjNcX/xRDAcRPZBxJFt/tVQ3bK8XevOdoCql1pTR3Tpoy ArP01jTDNK8Xbe9/GkJ5X9Ae; 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 1lRyhE-0007Rp-QU; Thu, 01 Apr 2021 14:53:20 +0000 Subject: Re: [PATCH 2/8] kernel: unmask SIGSTOP for IO threads From: Stefan Metzmacher To: Jens Axboe , Oleg Nesterov Cc: io-uring@vger.kernel.org, torvalds@linux-foundation.org, ebiederm@xmission.com, linux-kernel@vger.kernel.org References: <20210326003928.978750-1-axboe@kernel.dk> <20210326003928.978750-3-axboe@kernel.dk> <20210326134840.GA1290@redhat.com> <8f2a4b48-77c9-393f-5194-100ed63c05fc@samba.org> <58f67a8b-166e-f19c-ccac-157153e4f17c@kernel.dk> Message-ID: Date: Thu, 1 Apr 2021 16:53:12 +0200 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: 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 Hi Jens, >>> I don't assume signals wanted by userspace should potentially handled in an io_thread... >>> e.g. things set with fcntl(fd, F_SETSIG,) used together with F_SETLEASE? >> >> I guess we do actually need it, if we're not fiddling with >> wants_signal() for them. To quell Oleg's concerns, we can just move it >> to post dup_task_struct(), that should eliminate any race concerns >> there. > > If that one is racy, don' we better also want this one? > https://lore.kernel.org/io-uring/438b738c1e4827a7fdfe43087da88bbe17eedc72.1616197787.git.metze@samba.org/T/#u > > And clear tsk->pf_io_worker ? As the workers don't clone other workers I guess it's fine to defer this to 5.13. metze