From owner-freebsd-performance@FreeBSD.ORG Thu Jan 6 19:40:35 2005 Return-Path: Delivered-To: freebsd-performance@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id C5AC516A4D2 for ; Thu, 6 Jan 2005 19:40:35 +0000 (GMT) Received: from fledge.watson.org (fledge.watson.org [204.156.12.50]) by mx1.FreeBSD.org (Postfix) with ESMTP id 4803943D1F for ; Thu, 6 Jan 2005 19:40:35 +0000 (GMT) (envelope-from robert@fledge.watson.org) Received: from fledge.watson.org (localhost [127.0.0.1]) by fledge.watson.org (8.13.1/8.13.1) with ESMTP id j06JanFb002832; Thu, 6 Jan 2005 14:36:49 -0500 (EST) (envelope-from robert@fledge.watson.org) Received: from localhost (robert@localhost)j06Janm3002829; Thu, 6 Jan 2005 19:36:49 GMT (envelope-from robert@fledge.watson.org) Date: Thu, 6 Jan 2005 19:36:49 +0000 (GMT) From: Robert Watson X-Sender: robert@fledge.watson.org To: stheg olloydson In-Reply-To: <20050106174100.18034.qmail@web53908.mail.yahoo.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII cc: phil.brennan@gmail.com cc: freebsd-performance@freebsd.org Subject: Re: Benchmark: NetBSD 2.0 [allegedly] beats FreeBSD 5.3 in server performance X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 06 Jan 2005 19:40:35 -0000 On Thu, 6 Jan 2005, stheg olloydson wrote: > it was said by Phil Brennan: > > >What about the context switch time? Are there any plans to improve > >this, and also to reduce the number of context switches needed? > > See Robert Watson's reply to this thread. An unfortunate number of > problems exist in threading and scheduling. Most are well-understood and > are being worked on and 5.4 should see measurable improvement. > Personally, I am more concerned with network and scheduler perfomance. > I know the former is being addressed, but I don't hear anything about > how work on SCHED_ULE is progressing. FWIW, one of the reasons that there hasn't been as much interest in SCHED_ULE lately is likely that several of the features previously only present in SCHED_ULE are now also present in SCHED_4BSD -- for example, making more effective uses of IPIs in reducing latency during inter-process communication across processors. While SCHED_ULE does contain a number of interesting things not present in SCHED_4BSD, the 4BSD scheduler has hardly gone un-improved in that time. However, Jeff Robserson does seem to have picked up recently on both VFS SMP locking and ULE. The scheduler tracing and visualization tools he committed a couple of weeks ago are really quite neat tools. Robert N M Watson