From owner-freebsd-hackers Fri Aug 11 11:13:59 2000 Delivered-To: freebsd-hackers@freebsd.org Received: from fw.wintelcom.net (ns1.wintelcom.net [209.1.153.20]) by hub.freebsd.org (Postfix) with ESMTP id 6E75337B529 for ; Fri, 11 Aug 2000 11:13:53 -0700 (PDT) (envelope-from bright@fw.wintelcom.net) Received: (from bright@localhost) by fw.wintelcom.net (8.10.0/8.10.0) id e7BIDmG23728; Fri, 11 Aug 2000 11:13:48 -0700 (PDT) Date: Fri, 11 Aug 2000 11:13:48 -0700 From: Alfred Perlstein To: Jonas Bulow Cc: hackers@FreeBSD.ORG Subject: Re: R. Stevens select() Collisions Scenario Message-ID: <20000811111348.Z4854@fw.wintelcom.net> References: <39934E64.A5BEE8EE@earthlink.net> <20000810180838.V4854@fw.wintelcom.net> <39943B24.90B7AB04@servicefactory.se> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.4i In-Reply-To: <39943B24.90B7AB04@servicefactory.se>; from jonas.bulow@servicefactory.se on Fri, Aug 11, 2000 at 07:43:00PM +0200 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG * Jonas Bulow [000811 10:45] wrote: > Alfred Perlstein wrote: > > Yes. :) When FreeBSD gets scheduler activations you'll be able to change > > to a single threaded process that will have excellent performance, the > > scheduler activations are just around the corner. > > Can you explain what scheduler activations are? Please CC. schedulder activations are like 'LWP on-demand' a really simplified explanation would be shared address space fork that only happens when you block in certain parts of the kernel, like during disk/io. the problem with normal LWP is that if you're going to do any sort of disk IO you really want an LWP _per_ disk bound thread otherwise you risk blocking on disk IO inside the kernel, scheduler activations make sure you almost never block as well as making it unnecessary to 'pre-allocate' LWP contexts to avoid such problems. -- -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-hackers" in the body of the message