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=-2.3 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 5BF1AC47404 for ; Tue, 8 Oct 2019 03:16:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 284732067B for ; Tue, 8 Oct 2019 03:16:17 +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="EC8MmHG9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729730AbfJHDQQ (ORCPT ); Mon, 7 Oct 2019 23:16:16 -0400 Received: from mail-pf1-f196.google.com ([209.85.210.196]:37343 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729536AbfJHDQQ (ORCPT ); Mon, 7 Oct 2019 23:16:16 -0400 Received: by mail-pf1-f196.google.com with SMTP id y5so9948785pfo.4 for ; Mon, 07 Oct 2019 20:16:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-language:content-transfer-encoding; bh=poSeUmgsFcrtpobHMzRXdKMeRSGiKvfSXp6vT7FntzM=; b=EC8MmHG9FC6YdTgUY8O+2sWYnZ3kCo7s/m9v/l6q117ZinMXs8MDYsdyyOyBdSpqn7 3pKah4hWrMigWpyKw96dKQKk9jcBZ6rTForIQjYmrodIeQhx0xUp6YmeNWoiMNeh8fj6 aXSwXoM4+WcrzwrI/3QLatcAHwjfpY5coBnY6gTMzMeN8mC0iMhxoc6asdx680n9QBnj kQhwMNTb1OBsGLuR6/vdYhq2dZUudsVptvY5wHZN2DNVaSc0qMAhn4mW+ZQE+g01KaDM rLCOszqBWsXJzfVG5RCPEBJmYVpmkEO2BPiC0Arx5eeSgNjwomJoa+pAqSqox/L4XS5Z Gstw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=poSeUmgsFcrtpobHMzRXdKMeRSGiKvfSXp6vT7FntzM=; b=TlW9GicePyzDRVYmXRUJVlBc1uN4DPdfFt9d4nIwM506K+E5vokG9laO45bGFo+7IX liJChHXrk/fGYOm1K2U6KnlseEPm46rHm7vufnGfX4/PQTFGLSOoZJ9ejjK/TnuimUqY JUKg+3xiaqplGGR9E1kdbc7AJDuh2HKCLR3cPCfX/gS+Ze8Z5sQL42oiQ9RAbU25g1kx 2EMCvJNmc778u+Euk9BewUVTUkFi+KuOB/ZxROPhaMkOvDAZ1cYwP2YYx6SJAYSyXEtb DwTGKAgoygOT30XKhXmZ+SpasjYQrxRirpmTZvnDwdumJCN8RAU8Y7Q2hHSbJmyfl25a ikyQ== X-Gm-Message-State: APjAAAVRyF8JhAUixiLwJbRIyFulRnkGc+nARk6U+lVBeDJEzTFJxDBc k1NtFm0oBhD8rKljpRSpmcNwlsw3i11Mng== X-Google-Smtp-Source: APXvYqxI/PH0k5yN2ZewrIuX/p/y+QoJg1zBhrX+rYKTptAO/sK5tV4g7b/X5hI5cgPiijAdtrD4ww== X-Received: by 2002:a17:90a:5d0f:: with SMTP id s15mr2965996pji.126.1570504575619; Mon, 07 Oct 2019 20:16:15 -0700 (PDT) Received: from [192.168.1.188] ([66.219.217.79]) by smtp.gmail.com with ESMTPSA id l62sm20530031pfl.167.2019.10.07.20.16.14 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 07 Oct 2019 20:16:14 -0700 (PDT) Subject: Re: [PATCH] io_uring: remove wait loop spurious wakeups To: "Pavel Begunkov (Silence)" , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org References: <936cd758d6c694fe1b8b9de050e24cfecdc2e60d.1570489620.git.asml.silence@gmail.com> From: Jens Axboe Message-ID: Date: Mon, 7 Oct 2019 21:16:12 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <936cd758d6c694fe1b8b9de050e24cfecdc2e60d.1570489620.git.asml.silence@gmail.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 10/7/19 5:18 PM, Pavel Begunkov (Silence) wrote: > From: Pavel Begunkov > > Any changes interesting to tasks waiting in io_cqring_wait() are > commited with io_cqring_ev_posted(). However, io_ring_drop_ctx_refs() > also tries to do that but with no reason, that means spurious wakeups > every io_free_req() and io_uring_enter(). > > Just use percpu_ref_put() instead. Looks good, this is a leftover from when the ctx teardown used the waitqueue as well. -- Jens Axboe