From owner-freebsd-arch Wed Dec 1 14:31:32 1999 Delivered-To: freebsd-arch@freebsd.org Received: from ns1.yes.no (ns1.yes.no [195.204.136.10]) by hub.freebsd.org (Postfix) with ESMTP id 69D5C14A03 for ; Wed, 1 Dec 1999 14:31:29 -0800 (PST) (envelope-from eivind@bitbox.follo.net) Received: from bitbox.follo.net (bitbox.follo.net [195.204.143.218]) by ns1.yes.no (8.9.3/8.9.3) with ESMTP id XAA02228 for ; Wed, 1 Dec 1999 23:31:19 +0100 (CET) Received: (from eivind@localhost) by bitbox.follo.net (8.8.8/8.8.6) id XAA79174 for freebsd-arch@freebsd.org; Wed, 1 Dec 1999 23:31:19 +0100 (MET) Received: from test.tar.com (test.tar.com [204.95.187.4]) by hub.freebsd.org (Postfix) with ESMTP id 02EF214BF4 for ; Wed, 1 Dec 1999 14:31:08 -0800 (PST) (envelope-from dick@test.tar.com) Received: (from dick@localhost) by test.tar.com (8.9.3/8.9.3) id QAA24430; Wed, 1 Dec 1999 16:30:32 -0600 (CST) (envelope-from dick) Date: Wed, 1 Dec 1999 16:30:32 -0600 From: "Richard Seaman, Jr." To: Wes Peters Cc: "Richard Seaman, Jr." , "Daniel M. Eischen" , arch@freebsd.org Subject: Re: Threads stuff Message-ID: <19991201163032.G29767@tar.com> References: <384270AE.D0250340@vigrid.com> <38440BAB.E547CA61@vigrid.com> <19991130122423.N29767@tar.com> <38459FEF.B04F4617@softweyr.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 1.0pre3i In-Reply-To: <38459FEF.B04F4617@softweyr.com> Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Wed, Dec 01, 1999 at 03:23:43PM -0700, Wes Peters wrote: > "Richard Seaman, Jr." wrote: > > > > On Tue, Nov 30, 1999 at 12:38:51PM -0500, Daniel M. Eischen wrote: > > > > > I think we can perform thread switches totally in > > > userland without any assistance from the kernel. > > > > This would be a big performance plus. > > Not if you want those threads to run on multiple processors in an SMP box. I doubt you can eliminate all kernel calls for context switches when you have multiple processors, or even when you want multiple scheduler classes on UP. But, if you're only rescheduling a thread on the same KSE in response to a userland block or other event, then I can see this as possible, and as a win. -- Richard Seaman, Jr. email: dick@tar.com 5182 N. Maple Lane phone: 262-367-5450 Chenequa WI 53058 fax: 262-367-5852 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message