From owner-freebsd-performance@FreeBSD.ORG Fri Jan 28 01:04:33 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 8CD9B16A4CE for ; Fri, 28 Jan 2005 01:04:33 +0000 (GMT) Received: from rproxy.gmail.com (rproxy.gmail.com [64.233.170.202]) by mx1.FreeBSD.org (Postfix) with ESMTP id AE24943D4C for ; Fri, 28 Jan 2005 01:04:31 +0000 (GMT) (envelope-from linicks@gmail.com) Received: by rproxy.gmail.com with SMTP id 40so279244rnz for ; Thu, 27 Jan 2005 17:04:31 -0800 (PST) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:reply-to:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:references; b=rUTuN+HHQe/zShltRufJHCkAz3sjYr+Wg7+Sr8W/R+XmQcu7xc68qu8vNGj8GVGtCB0ez1KxfZxU+23qJpLKCSKwsec5FwdjbTPTOmDg8ideP25leuysc8g4A8G0ej7RBWBLMsjclMFZQIJK5CDORPygTFGThKIg5j1gQ4sa168= Received: by 10.38.206.57 with SMTP id d57mr56805rng; Thu, 27 Jan 2005 17:04:31 -0800 (PST) Received: by 10.38.8.43 with HTTP; Thu, 27 Jan 2005 17:04:31 -0800 (PST) Message-ID: Date: Thu, 27 Jan 2005 18:04:31 -0700 From: Nick Pavlica To: Robert Watson In-Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit References: <6.2.0.14.0.20050126150959.0466f4b8@64.7.153.2> cc: freebsd-performance@freebsd.org cc: freebsd-questions@freebsd.org cc: Mike Tancsa Subject: Re: FreeBSD 5.3 I/O Performance / Linux 2.6.10 | Continued Discussion X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: Nick Pavlica List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 28 Jan 2005 01:04:33 -0000 > The move to an MPSAFE VFS will help with that a lot, I should think. Do you know if this will find it's way to 5.x in the near future? > > Also, while on face value this may seem odd, could you try the following > additional variables: > > - Layer the test UFS partition directly over ad0 instead of ad0s1a > - UFS1 vs UFS2 I just tested with UFS1 and had almost the exact same results. > > Finally, in as much as is possible, make sure that the layout of the disks > is approximately the same -- as countless benchmarking papers show, there > are substantial differences (10%+) in I/O throughput depending on where on > the disk surface operations occur. That's one of the reasons to try UFS1 > for the test partition, although not the only one. My tests use the exact same disk layout, and hardware. However, I have had consistent results on all 4 boxes that I have tested on. At this point I'm making the assumption that the poor disk I/O performance on 5.3 isn't a file system issue, but is tied to a larger issue with the Kernel (I know never make assumptions ... :)). In all my testing, I have noticed that 5.3 doesn't appear to release cpu resources even if there isn't any other demand for resources. I would compare it to driveling a car with a governor on it. When I tested with 4.11, it allocated considerably more resources. I do hope that the 5.x issues are resolved soon so that I can deploy may production servers on it rather than starting on 4 and them making the big switch. I will probably test 6 for the fun of it. Thanks! --Nick Pavlica