From owner-freebsd-arch Thu Nov 30 23:30:46 2000 Delivered-To: freebsd-arch@freebsd.org Received: from fw.wintelcom.net (ns1.wintelcom.net [209.1.153.20]) by hub.freebsd.org (Postfix) with ESMTP id 32A9937B401 for ; Thu, 30 Nov 2000 23:30:44 -0800 (PST) Received: (from bright@localhost) by fw.wintelcom.net (8.10.0/8.10.0) id eB17Ubg23792; Thu, 30 Nov 2000 23:30:37 -0800 (PST) Date: Thu, 30 Nov 2000 23:30:37 -0800 From: Alfred Perlstein To: "Kenneth D. Merry" Cc: Bosko Milekic , Andrew Gallatin , arch@FreeBSD.ORG Subject: Re: zero copy code review Message-ID: <20001130233037.L8051@fw.wintelcom.net> References: <14886.63486.157224.937225@grasshopper.cs.duke.edu> <20001201002235.D10772@panzer.kdm.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <20001201002235.D10772@panzer.kdm.org>; from ken@kdm.org on Fri, Dec 01, 2000 at 12:22:35AM -0700 Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG * Kenneth D. Merry [001130 23:22] wrote: > On Thu, Nov 30, 2000 at 22:18:43 -0500, Bosko Milekic wrote: > > On Thu, 30 Nov 2000, Andrew Gallatin wrote: > > > > [...] > > > <... some helpful comments deleted ....> > > > > > > Many of your comments are directly related to -current, I > > > think I'll let Ken address them... > > > > Another one directly related to -CURRENT: > > > > I just noticed that the uipc_jumbo.c stuff does not do any locking. > > Perhaps it would be nice to lock the code sooner or later. I would be > > willing to go over it and do it but, as I said, I am really not going to > > be able to do much until 2 weeks from now. > > It does have spls in the right places, in this case splimp() and splvm(). > Would you just convert those to the proper mutexes, or are we going to go > with per-data-structure mutexes (i.e. a little finer granularity), or...? > (I don't know much about the mutex strategy we're using...) The vm system is likely to be the last thing to be locked down, if your code dips in the vm system you'll have to aquire Giant, possibly several times through your codepath, the performance can drop dramatically for the SMP case. -- -Alfred Perlstein - [bright@wintelcom.net|alfred@freebsd.org] "I have the heart of a child; I keep it in a jar on my desk." To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message