From owner-freebsd-hackers Wed Jun 23 22:21:58 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from psf.Pinyon.ORG (unknown [205.253.70.175]) by hub.freebsd.org (Postfix) with ESMTP id 6B918155A5 for ; Wed, 23 Jun 1999 22:21:47 -0700 (PDT) (envelope-from rcarter@psf.Pinyon.ORG) Received: from psf.Pinyon.ORG (localhost [127.0.0.1]) by psf.Pinyon.ORG (8.9.3/8.9.2) with ESMTP id WAA26709; Wed, 23 Jun 1999 22:20:24 -0700 (MST) (envelope-from rcarter@psf.Pinyon.ORG) Message-Id: <199906240520.WAA26709@psf.Pinyon.ORG> X-Mailer: exmh version 2.0.2 2/24/98 To: Julian Elischer Cc: hackers@freebsd.org Subject: Re: Microsoft performance (was: ...) In-reply-to: Your message of "Wed, 23 Jun 1999 21:45:42 MST." Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Wed, 23 Jun 1999 22:20:24 -0700 From: "Russell L. Carter" Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG % % %On Wed, 23 Jun 1999, Russell L. Carter wrote: % %> %> %Basically there are some applications and benchmarks for which FreeBSD %> %> uh, "benchmarks" only, until evidence is produced otherwise. [...] %ok here are some of the problems.. % %Matt's changes allow dd to copy data at 2.5 times the rate it did before. %I consider dd to be an application. The problem is due to resource %handling in the kernel and results in large amounts of Idle CPU time. Ok, why doesn't this show up in any of the disk or network benchmarks? %Another primary problem with the FreeBSD kernel (being addressed by Kirk) %is that after writing a file, once the data has been queued for IO you %cannot read the data in that file (even though it is present) until the IO %is complete. With 64 tags, it is concievable that this could take a half %second on a modern disk. That's interesting. %These are problems shown up by the benchmarks but %which can be shown to affect ordinary operations. % %There are other problems related to SMP and the GKL.. %e.g.. two processes cannot access buffers at the same time, even though %they are both present , because only one of them is allowed in the kernel %at a time. Therefore One processor will spend a bunch of time at idle.. Yup. Thanks for filling us in! Russell To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message