From owner-freebsd-smp Tue Jun 29 15:19:43 1999 Delivered-To: freebsd-smp@freebsd.org Received: from smtp01.primenet.com (smtp01.primenet.com [206.165.6.131]) by hub.freebsd.org (Postfix) with ESMTP id CCEF514C10 for ; Tue, 29 Jun 1999 15:19:40 -0700 (PDT) (envelope-from tlambert@usr08.primenet.com) Received: (from daemon@localhost) by smtp01.primenet.com (8.8.8/8.8.8) id PAA20560; Tue, 29 Jun 1999 15:19:39 -0700 (MST) Received: from usr08.primenet.com(206.165.6.208) via SMTP by smtp01.primenet.com, id smtpd020393; Tue Jun 29 15:19:27 1999 Received: (from tlambert@localhost) by usr08.primenet.com (8.8.5/8.8.5) id PAA00305; Tue, 29 Jun 1999 15:19:23 -0700 (MST) From: Terry Lambert Message-Id: <199906292219.PAA00305@usr08.primenet.com> Subject: Re: high-efficiency SMP locks - submission for review To: vanmaren@fast.cs.utah.edu (Kevin Van Maren) Date: Tue, 29 Jun 1999 22:19:22 +0000 (GMT) Cc: tlambert@primenet.com, vanmaren@cs.utah.edu, freebsd-smp@FreeBSD.ORG In-Reply-To: <199906292144.PAA27790@fast.cs.utah.edu> from "Kevin Van Maren" at Jun 29, 99 03:44:16 pm X-Mailer: ELM [version 2.4 PL25] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-smp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org > I also recall hearing that Solaris was slower on a uniprocessor > than FreeBSD, partly due to the locking/synchronization in the kernel. I credit this to their VFS reentrancy model, which I think is The Wrong Way To Do It. I think that locking objects instead of locking entrancy to the small bits of code that modify such objects is probably the culprit. When you lock object with fine granularity, you aren't saying enough about how long you hold the locks. The object lock cost is much higher than necessary or desirable, IMO. > > FreeBSD did worse than Linux, both SMP and UP. > > I didn't see any FreeBSD numbers; I'll have to go look again. The FreeBSD numbers are from Ziff-Davis via Mike Smith. > It wasn't that long ago FreeBSD was beating the pants off Linux. > I guess we've been standing too still for too long. Time for FreeBSD to wake up... Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message