From owner-freebsd-stable@FreeBSD.ORG Sat Dec 22 08:34:08 2007 Return-Path: Delivered-To: stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id C5C8116A468 for ; Sat, 22 Dec 2007 08:34:08 +0000 (UTC) (envelope-from kometen@gmail.com) Received: from an-out-0708.google.com (an-out-0708.google.com [209.85.132.243]) by mx1.freebsd.org (Postfix) with ESMTP id 8868913C45B for ; Sat, 22 Dec 2007 08:34:08 +0000 (UTC) (envelope-from kometen@gmail.com) Received: by an-out-0708.google.com with SMTP id c14so164865anc.13 for ; Sat, 22 Dec 2007 00:34:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; bh=WrsETWUWPjPtD/mNxQbMARsT9op3CKZX5PGVBlaH4Dk=; b=rkpxfEaRIT65825BKk2ucC+qWAURIxwdg3y3HRc+pMmNS66p6RBaCxYSHbDoLHw4k9Ec4EJxOnsDwkVJnBKkwGhpMHcQEKVvIfdKMdEQ0pLLm9VC3Wmq2reQFfP7dkbrWTXwQ7AFAJIJTWk84V7/Vp0ghSRRRFffrnoHEkOlNps= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=cUMeho0kFdgQm9eL6lxe6BxvoxwMXYfe9qmIivB8j+oj13J4TWMS1/UsaxzWEyjQlnXjxGa1PATuSKdE4I0RbGuo1wU3umRu7N1Vq71+i6YlQhhXju90vk3fe6+F6GmlEjpjz74FGUaf3kRJOKV2rWdCIXVgJZ/ko+UANY2zOQ8= Received: by 10.100.247.14 with SMTP id u14mr2662612anh.79.1198310882828; Sat, 22 Dec 2007 00:08:02 -0800 (PST) Received: by 10.100.228.15 with HTTP; Sat, 22 Dec 2007 00:08:02 -0800 (PST) Message-ID: Date: Sat, 22 Dec 2007 09:08:02 +0100 From: "Claus Guttesen" To: "Brett Glass" In-Reply-To: <200712220531.WAA09277@lariat.net> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <200712220531.WAA09277@lariat.net> Cc: stable@freebsd.org Subject: Re: SMP on FreeBSD 6.x and 7.0: Worth doing? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 22 Dec 2007 08:34:08 -0000 > I will need to build several Web caches over the next few months, > and just took advantage of the Christmas lull (and a snowy day, > when I couldn't work outside) to test FreeBSD 7.0 BETA 4 to see how > it will perform at this task. I built up a 4 core FreeBSD box, and > asked a friend who's a Linux fanatic to do the same with Linux on > identical hardware. I didn't watch closely how he installed > everything, but asked him not to tune it beyond setting it up > properly for SMP. > > We then ran a test suite in which a client starts several > processes. Each uses wget to fetch a series of objects in rapid > succession via the cache. The fetches done by each process are the > same batch of URLS, but shuffled differently, so each URL will get > a miss the first time and then hits each time it comes up > thereafter unless the cache overflows. We're doing all GETs, with > no tricky stuff like subranges. > > As has been reported in some other messages on this list, Linux is > currently blowing FreeBSD away. It's taking as much as 20% less > time to get through the benchmark, depending on exactly how the > random shuffle came out. This is with 4 GB RAM, the GENERIC FreeBSD > SMP kernel (using SCHED_ULE), and aufs as the storage schema for Squid. > > It appears, though I'd need to instrument the code more to be sure, > that the slowdown is coming from file I/O. Could it be that there > less concurrency or more overhead in FreeBSD file operations than > there is in Linux? Even with SoftUpdates turned on, the cache > volume mounted with -noatime, and aufs (which uses kqueues -- a > FreeBSD invention -- to optimize multithreaded disk access), the > benchmark shows FreeBSD losing out. Why? I have noticed an entry in GENERIC called device cpufreq Could this have any influence on the performance (on FreeBSD)? I saw this device late in the 7.0 release-process and I since I'm accustomed to comment out any devices and options I don't need I have commented this out as well. So I haven't performed any tests with and without this device. -- regards Claus When lenity and cruelty play for a kingdom, the gentlest gamester is the soonest winner. Shakespeare