From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 16 May 2001 10:04:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 16 May 2001 10:04:25 -0400 Received: from penguin.e-mind.com ([195.223.140.120]:34842 "EHLO penguin.e-mind.com") by vger.kernel.org with ESMTP id ; Wed, 16 May 2001 10:04:22 -0400 Date: Wed, 16 May 2001 16:04:12 +0200 From: Andrea Arcangeli To: dean gaudet Cc: linux-kernel@vger.kernel.org Subject: Re: 2.2.20pre2aa1 Message-ID: <20010516160412.B15796@athlon.random> In-Reply-To: <20010515235859.A2415@athlon.random> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: ; from dean-list-linux-kernel@arctic.org on Tue, May 15, 2001 at 08:33:05PM -0700 X-GnuPG-Key-URL: http://e-mind.com/~andrea/aa.gnupg.asc X-PGP-Key-URL: http://e-mind.com/~andrea/aa.asc Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 15, 2001 at 08:33:05PM -0700, dean gaudet wrote: > On Tue, 15 May 2001, Andrea Arcangeli wrote: > > > o fixed race in wake-one LIFO in accept(2). Apache must be compiled with > > -DSINGLE_LISTEN_UNSERIALIZED_ACCEPT to take advantage of that. > > > > 00_wake-one-4 > > > > Backport 2.4 waitqueues and in turn fixes an hanging condition in accept(2). > > > > (me) > > apache since 1.3.15 has defined SINGLE_LISTEN_UNSERIALIZED_ACCEPT ... That's definitely a good thing. > 'cause that's what you guys asked me to do :) does this mean there are > known hangs on linux 2.2.x without your fix? I never heard of anybody reproducing that but accpet() in 2.2 can _definitely_ miss events without the above 00_wake-one-4 patch because it wrongly considers a progress wakeing up two times the same exclusive task. Furthmore the exclusive wakeup logic with the exclusive information per-task and not per wait_queue_t will screwup if the tasks registers itself like a wakeall after it was just registered as wakeone somewhere else (however this second thing is more a theorical issue that shouldn't trigger in 2.2). Andrea