Date: Wed, 18 Feb 2009 09:49:32 -0500 From: John Baldwin <jhb@freebsd.org> To: Bruce Simpson <bms@incunabulum.net> 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 Message-ID: <200902180949.32691.jhb@freebsd.org> In-Reply-To: <499BC43B.6030701@incunabulum.net> References: <200902171957.n1HJvqk8026145@svn.freebsd.org> <499BC43B.6030701@incunabulum.net>
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On Wednesday 18 February 2009 3:18:03 am Bruce Simpson wrote: > 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. When Kris tested it, it made things significantly better. I'm not sure if it resolved all the issues though. -- John Baldwin
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