From owner-svn-src-stable@FreeBSD.ORG Wed Feb 18 08:18:08 2009 Return-Path: Delivered-To: svn-src-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id EC7EE106566C; Wed, 18 Feb 2009 08:18:07 +0000 (UTC) (envelope-from bms@incunabulum.net) Received: from out5.smtp.messagingengine.com (out5.smtp.messagingengine.com [66.111.4.29]) by mx1.freebsd.org (Postfix) with ESMTP id B79358FC15; Wed, 18 Feb 2009 08:18:07 +0000 (UTC) (envelope-from bms@incunabulum.net) Received: from compute1.internal (compute1.internal [10.202.2.41]) by out1.messagingengine.com (Postfix) with ESMTP id 86E38299991; Wed, 18 Feb 2009 03:18:06 -0500 (EST) Received: from heartbeat2.messagingengine.com ([10.202.2.161]) by compute1.internal (MEProxy); Wed, 18 Feb 2009 03:18:06 -0500 X-Sasl-enc: 9VbU2RwHv594ZFsVm+gAl7DYpB7x1cGKod1xWkeizewT 1234945086 Received: from [192.168.123.18] (82-35-112-254.cable.ubr07.dals.blueyonder.co.uk [82.35.112.254]) by mail.messagingengine.com (Postfix) with ESMTPSA id A5E4720617; Wed, 18 Feb 2009 03:18:05 -0500 (EST) Message-ID: <499BC43B.6030701@incunabulum.net> Date: Wed, 18 Feb 2009 08:18:03 +0000 From: Bruce Simpson User-Agent: Thunderbird 2.0.0.19 (Windows/20081209) MIME-Version: 1.0 To: John Baldwin References: <200902171957.n1HJvqk8026145@svn.freebsd.org> In-Reply-To: <200902171957.n1HJvqk8026145@svn.freebsd.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: svn-src-stable@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org, svn-src-stable-7@freebsd.org Subject: Re: svn commit: r188727 - in stable/7: sys sys/contrib/pf sys/dev/ath/ath_hal sys/dev/cxgb sys/kern sys/modules/sem sys/sys tools/regression/posixsem usr.bin/procstat X-BeenThere: svn-src-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for all the -stable branches of the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 18 Feb 2009 08:18:09 -0000 John Baldwin wrote: > Author: jhb > Date: Tue Feb 17 19:57:52 2009 > New Revision: 188727 > URL: http://svn.freebsd.org/changeset/base/188727 > > Log: > MFC: Rework the lifetime management of the kernel implementation of POSIX > semaphores. Specifically, semaphores are now represented as new file > descriptor type that is set to close on exec. This removes the need for > all of the manual process reference counting (and fork, exec, and exit > event handlers) as the normal file descriptor operations handle all of > that for us nicely. It is also suggested as one possible implementation > in the spec and at least one other OS (OS X) uses this approach. FYI: This change *may* fix Python 2.6's 'multiprocessing' module on FreeBSD 7-STABLE, which is known to have problems there; it depends on POSIX semaphores to synchronize its IPC between different fork()'s of the Python interpreter. If anyone else has an interest in ths they may wish to test, if not, I will try to get around to it eventually. cheers BMS