From owner-freebsd-hackers Wed Feb 10 13:36:21 1999 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id NAA22206 for freebsd-hackers-outgoing; Wed, 10 Feb 1999 13:36:21 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from iquest3.iquest.net (iquest3.iquest.net [209.43.20.203]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id NAA22200 for ; Wed, 10 Feb 1999 13:36:19 -0800 (PST) (envelope-from toor@y.dyson.net) Received: (qmail 4226 invoked from network); 10 Feb 1999 21:36:15 -0000 Received: from dyson.iquest.net (HELO y.dyson.net) (198.70.144.127) by iquest3.iquest.net with SMTP; 10 Feb 1999 21:36:15 -0000 Received: (from root@localhost) by y.dyson.net (8.9.1/8.9.1) id QAA02545; Wed, 10 Feb 1999 16:36:15 -0500 (EST) Message-Id: <199902102136.QAA02545@y.dyson.net> Subject: Re: portability of shm, mmap, pipes and socket IPC In-Reply-To: <199902101724.KAA13526@usr07.primenet.com> from Terry Lambert at "Feb 10, 99 05:24:00 pm" To: tlambert@primenet.com (Terry Lambert) Date: Wed, 10 Feb 1999 16:36:15 -0500 (EST) Cc: dg@root.com, dillon@apollo.backplane.com, tlambert@primenet.com, kuku@gilberto.physik.RWTH-Aachen.DE, hackers@FreeBSD.ORG From: "John S. Dyson" Reply-To: dyson@iquest.net X-Mailer: ELM [version 2.4ME+ PL38 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Terry Lambert said: > > I guess if we are still examining Linux vs. FreeBSD programming, then > I should probably point out that SysV SHM is faster than non-anonymous > mmap'ed memory, because writes don't have to be written through to the > backing object. > The condition for paging out pages to SysV SHM are very similar to anonymous MMAPed regions. There is no effective difference. If you use file backed MMAPed regions, there are some time consuming sync operations though. -- John | Never try to teach a pig to sing, dyson@iquest.net | it makes one look stupid jdyson@nc.com | and it irritates the pig. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message