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=-2.2 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 64A5FC3F2D1 for ; Wed, 4 Mar 2020 18:42:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3A78C24654 for ; Wed, 4 Mar 2020 18:42:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="1V8CEMS2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388290AbgCDSmm (ORCPT ); Wed, 4 Mar 2020 13:42:42 -0500 Received: from mail-io1-f65.google.com ([209.85.166.65]:35018 "EHLO mail-io1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388203AbgCDSmm (ORCPT ); Wed, 4 Mar 2020 13:42:42 -0500 Received: by mail-io1-f65.google.com with SMTP id h8so3579269iob.2 for ; Wed, 04 Mar 2020 10:42:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=aowmqH+jxIIMHfi6cwVjuOMBAQUGZOtVBythXJlq3wg=; b=1V8CEMS2GN8MJvUzIknKJZighpn0smIcGnGnvbOS0TIHXyZ56NJcxHzYemcc3pfQke IhWQa/jjgQJA0iN+8Pi3PmbvC0xibsjBFGVarOG6kgTFTfLtTiFST6bIFH7dtpdPEiMr PXDLO25Kyz34aDn88pu35XYZOSINx5EOUFgM6coZ1+YOaOup55jp1+zqVY3kEZxqNvze t+OU1lT3pEb5gk4PpPF+ZkqZAWpI6INeHxbf89go8rQ2DYwVWgd7l4+C+DXMidklJQGj NcmU+khDtpifCoXjr2XzIcS+yW3r/CeLCWA0jHPG30hrLQxEF7Ne0KLt8lkity9Bc5KS q30A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=aowmqH+jxIIMHfi6cwVjuOMBAQUGZOtVBythXJlq3wg=; b=YHJiowyZtAhU72ky7jTm18roInGDNyESPVIxOxBsskbmV/nX6ErmBwhbpeOs1HapDm vITUjU5nAl/289jCd06K80/LNy6KX/TJyGf+vlFgXWE8XzhLxIefU9OldpC/exY+Zpm5 CwFOhdyTg3SDSvVq3/cCpH8uzmqasg/3STrb8LuYejIMn2OgQGaE+Nm1XWJq7UeOB6DA sEnPMPbOB5p1JBbPGfo1b9MCu6mJGkKkjhCe1lUaCZ2sVO7K27McP45Sea2qo+46XTiP sA8t7xiZt0VaWGRHCRySy7vsS/Bl8uViEurztsLqNpR2vkkvC5UFWIWV+dm8xqicYbid 5EwQ== X-Gm-Message-State: ANhLgQ1yCqtHtwmchtLywJIyc6YtSC/y5XvRQU3fYy3OjIrNTO1V+Tt4 sjJwzS8orOUzbE9Tw9VFUpEmnw== X-Google-Smtp-Source: ADFU+vtNXdELHZMcZy9b77s22L7Z+lfjHm6Swz0+NNeBTzLXUJ1tqb7ebPuKv66GC+EtaS0Ndiyweg== X-Received: by 2002:a02:6a10:: with SMTP id l16mr3894513jac.77.1583347361774; Wed, 04 Mar 2020 10:42:41 -0800 (PST) Received: from [192.168.1.159] ([65.144.74.34]) by smtp.gmail.com with ESMTPSA id l18sm7105635ild.51.2020.03.04.10.42.40 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 04 Mar 2020 10:42:41 -0800 (PST) Subject: Re: [PATCH 1/2] bcache: ignore pending signals in bcache_device_init() To: Oleg Nesterov , Michal Hocko Cc: Coly Li , linux-bcache@vger.kernel.org, linux-block@vger.kernel.org, hare@suse.de, mkoutny@suse.com References: <20200302093450.48016-1-colyli@suse.de> <20200302093450.48016-2-colyli@suse.de> <20200302122748.GH4380@dhcp22.suse.cz> <20200302134919.GB9769@redhat.com> <20200303080544.GW4380@dhcp22.suse.cz> <20200303121918.GA27520@redhat.com> <20200303160307.GI4380@dhcp22.suse.cz> <20200304113613.GA13170@redhat.com> <20200304115330.GB13170@redhat.com> From: Jens Axboe Message-ID: <239a316b-3c43-019a-bef0-409110284789@kernel.dk> Date: Wed, 4 Mar 2020 11:42:39 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <20200304115330.GB13170@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 3/4/20 4:53 AM, Oleg Nesterov wrote: > On 03/04, Oleg Nesterov wrote: >> >> arch/arm/common/bL_switcher.c:bL_switcher_thread(). Why does it do >> flush_signals() ? signal_pending() must not be possible. It seems that >> people think that wait_event_interruptible() or even schedule() in >> TASK_INTERRUPTIBLE state can lead to a pending signal but this is not >> true. Of course, I could miss allow_signal() in bL_switch_to() paths... > > Jens, could you explain flush_signals() in io_sq_thread() ? I actually don't think that one is needed - the only one that io_uring needs, and which is valid, is flushing signals for the io-wq worker as we use that for cancelation. In any case, both are kthreads. -- Jens Axboe