From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753063AbZHPAx3 (ORCPT ); Sat, 15 Aug 2009 20:53:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752853AbZHPAx2 (ORCPT ); Sat, 15 Aug 2009 20:53:28 -0400 Received: from hera.kernel.org ([140.211.167.34]:41188 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751441AbZHPAx2 (ORCPT ); Sat, 15 Aug 2009 20:53:28 -0400 Message-ID: <4A875874.20401@kernel.org> Date: Sun, 16 Aug 2009 09:53:08 +0900 From: Tejun Heo User-Agent: Thunderbird 2.0.0.22 (X11/20090605) MIME-Version: 1.0 To: Guillaume Knispel CC: linux-kernel@vger.kernel.org, Miklos Szeredi , Andrew Morton , Linus Torvalds , Alexander Viro , Arjan van de Ven , Heiko Carstens , Thomas Gleixner , linux-fsdevel@vger.kernel.org Subject: Re: [PATCH] poll/select: initialize triggered field of struct poll_wqueues References: <20090815193024.121926e6@xilun.lan.proformatique.com> In-Reply-To: <20090815193024.121926e6@xilun.lan.proformatique.com> X-Enigmail-Version: 0.95.7 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Sun, 16 Aug 2009 00:53:08 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Guillaume Knispel wrote: > poll/select: initialize triggered field of struct poll_wqueues > > The triggered field of struct poll_wqueues introduced in commit > 5f820f648c92a5ecc771a96b3c29aa6e90013bba "poll: allow f_op->poll to > sleep" was set to 1 in pollwake() (now __pollwake() ), tested and > later set to 0 in poll_schedule_timeout(), but not initialized before. > As a result when the process needs to sleep, triggered was likely to be > non-zero even if pollwake() is not called before the first > poll_schedule_timeout(), meaning schedule_hrtimeout_range() would not > be called and an extra loop calling all ->poll() would be done. > > This patch initialize triggered to 0 in poll_initwait() so the ->poll() > are not called twice before the process goes to sleep when it needs to. > > Signed-off-by: Guillaume Knispel Ah... nice spotting. Acked-by: Tejun Heo Thanks. -- tejun