From owner-freebsd-hackers Tue Jan 25 9:52:55 2000 Delivered-To: freebsd-hackers@freebsd.org Received: from apollo.backplane.com (apollo.backplane.com [216.240.41.2]) by hub.freebsd.org (Postfix) with ESMTP id BC4111526E for ; Tue, 25 Jan 2000 09:52:32 -0800 (PST) (envelope-from dillon@apollo.backplane.com) Received: (from dillon@localhost) by apollo.backplane.com (8.9.3/8.9.1) id JAA04953; Tue, 25 Jan 2000 09:52:31 -0800 (PST) (envelope-from dillon) Date: Tue, 25 Jan 2000 09:52:31 -0800 (PST) From: Matthew Dillon Message-Id: <200001251752.JAA04953@apollo.backplane.com> To: "Scott Hess" Cc: Subject: Re: Performance issue with rfork() and single socketpairs versus multiple socketpairs. References: <01b601bf6696$60701930$1e80000a@avantgo.com> <200001241939.LAA91219@apollo.backplane.com> <0be801bf6715$601423d0$1e80000a@avantgo.com> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG :OK, so let's say I did spend some time implementing it in terms of semget() :and semop(). Would you be totally apalled if the performance turned out to :be about the same as using a single socketpair? Do you have a very strong :feeling that it should be significantly better. [Again, under :3.4-release.] I don't think I've done anything egregious, but things don't :seem much better. Unfortunately, I'll have to wait until tomorrow morning :to rip things out and make a suitable example program for posting. : :Actually, the performance profile does seem different (for lower loads, the :semaphore solution seems more efficient), but the performance limits seem :much the same between the single socketpair and semaphore versions when I :starts using 16-20 worker processes. It's possible that I'm doing :.. : :Thanks, :scott Well, when all else fails --- go back to individual pipes. What else could be tried... you could try surrounding the read() with an flock() pair. I don't know if flock() uses the more optimal wakeup code or not. -Matt Matthew Dillon To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message