From owner-freebsd-hackers@FreeBSD.ORG Thu Feb 26 16:23:20 2009 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id DFD0A106566B; Thu, 26 Feb 2009 16:23:20 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from cyrus.watson.org (cyrus.watson.org [65.122.17.42]) by mx1.freebsd.org (Postfix) with ESMTP id B8CE78FC0C; Thu, 26 Feb 2009 16:23:20 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from fledge.watson.org (fledge.watson.org [65.122.17.41]) by cyrus.watson.org (Postfix) with ESMTPS id 516AA46BA0; Thu, 26 Feb 2009 11:23:20 -0500 (EST) Date: Thu, 26 Feb 2009 16:23:20 +0000 (GMT) From: Robert Watson X-X-Sender: robert@fledge.watson.org To: Tim Kientzle In-Reply-To: <49A5D6FC.1090800@freebsd.org> Message-ID: References: <49A5D6FC.1090800@freebsd.org> User-Agent: Alpine 2.00 (BSF 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: Siddharth Prakash Singh , freebsd-hackers@freebsd.org Subject: Re: Google SoC 2009 Idea X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 26 Feb 2009 16:23:21 -0000 On Wed, 25 Feb 2009, Tim Kientzle wrote: >> I have not gone through the process scheduler code of Free BSD. Hence, I am >> not yet aware about the current support for Multicore Architectures. > > Since you posted to a lot of different lists, I think you probably don't > already use FreeBSD. (If you did, why would you post to NetBSD and > DragonflyBSD lists?) Scheduler work is quite complex and interacts heavily > with the rest of the system; it may not be a good choice for someone who > doesn't already have a lot of experience with FreeBSD. All the things you say are true, but let's not be too hard on the new guy, however -- many of our GSoC students don't have previous FreeBSD kernel-hacking experience. However, it does mean that they have to pick project ideas that are well-suited to a significant warmup and investigation period on the front end of the project. I'm also not convinced that a scheduler project along these lines would be the most successful, but I wonder if a more experimental-spin proposal for looking at how to investigate poor scheduling decisions using dtrace, instrumentation and metrics to help us understand performance on NUMA systems, and exploring the impact of heuristics might go a long way. As our ULE scheduler has most of the non-NUMA features suggested in the original already, it would actually be a nice starting point for this. I understand Jeff Roberson has been doing some initial looking at NUMA, but more from a memory placement and less from a scheduling perspective? Robert N M Watson Computer Laboratory University of Cambridge > > You should probably tell us a little more about yourself: > > What kind of student? Graduate? Undergraduate? > Are you in a CS program or some other engineering program? > > Do you use FreeBSD? How long have you used it? > What do you do with it? > > Have you read Kirk McKusick's book on FreeBSD internals? > > Have you built and installed a FreeBSD system from source code? > > Have you taken classes on OS internals? > > How much C programming have you done? > > What areas of FreeBSD have you had the most problems with? > How would you make those areas better? > > Tim Kientzle > _______________________________________________ > freebsd-hackers@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-hackers > To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.org" >