From owner-freebsd-smp Mon Dec 7 12:12:59 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id MAA10342 for freebsd-smp-outgoing; Mon, 7 Dec 1998 12:12:59 -0800 (PST) (envelope-from owner-freebsd-smp@FreeBSD.ORG) Received: from post.mail.demon.net (post-12.mail.demon.net [194.217.242.41]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id MAA10312; Mon, 7 Dec 1998 12:12:47 -0800 (PST) (envelope-from james@westongold.com) Received: from [158.152.96.124] (helo=wgp01.wgold.demon.co.uk) by post.mail.demon.net with esmtp (Exim 2.054 #1) id 0zn71L-0001Q7-00; Mon, 7 Dec 1998 20:12:40 +0000 Received: by WGP01 with Internet Mail Service (5.5.1960.3) id ; Mon, 7 Dec 1998 19:59:15 -0000 Message-ID: <32BABEF63EAED111B2C5204C4F4F50201835@WGP01> From: James Mansion To: Gary Palmer , Michael Galassi Cc: Marcel van Kervinck , smp@FreeBSD.ORG Subject: RE: Pthreads and SMP Date: Mon, 7 Dec 1998 19:59:07 -0000 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.1960.3) Content-Type: text/plain Sender: owner-freebsd-smp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org I think what you wrote is not representative in many cases. Its not representative of ANY of my threaded development. I normally expect (and desire) threads to be spread over the system's CPUs. If I want to do a lot of IO, I'd rather set it up as aio_ or lio_ calls. Running a thread per client is very dangerous unless you KNOW that you will only run on systems that have an N:1 (ugh!) or M:N structure. Its not guaranteed by POSIX at all. While its clear that working on a hot structure from multiple threads can give your caches headaches, its by far the best way to handle concurrent queries against general data structures. Reducing contention is clearly a design issue of threaded development. It does seem that FreeBSD is some way from being leading edge as a platform for threaded or AIO applications - hopefully this will only be a temporary thing. James > -----Original Message----- > From: Gary Palmer [mailto:gpalmer@FreeBSD.ORG] ... > Seriously, there are advantages to thread migration and > disadvantages. I > believe Solaris only does thread migration when the CPU that > the process is on > is overcomitted. So unless you were totally CPU bound (in > which case the > process shouldn't have been threaded anyhow, as threads get > their advantage > from being I/O or network bound), there shouldn't really be a > problem... To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message