From owner-freebsd-xen@FreeBSD.ORG Fri Jan 30 12:53:26 2009 Return-Path: Delivered-To: freebsd-xen@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 123AE1065672 for ; Fri, 30 Jan 2009 12:53:26 +0000 (UTC) (envelope-from mister.olli@googlemail.com) Received: from mu-out-0910.google.com (mu-out-0910.google.com [209.85.134.185]) by mx1.freebsd.org (Postfix) with ESMTP id 8A01C8FC16 for ; Fri, 30 Jan 2009 12:53:25 +0000 (UTC) (envelope-from mister.olli@googlemail.com) Received: by mu-out-0910.google.com with SMTP id i2so391174mue.3 for ; Fri, 30 Jan 2009 04:53:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=domainkey-signature:received:received:subject:from:reply-to:to:cc :in-reply-to:references:content-type:date:message-id:mime-version :x-mailer:content-transfer-encoding; bh=pJUFS7WpGs+0Ie79//7TxABba2Gtf0sGc9uyewFK8u4=; b=rQxB1Edb03TvqhLt0eRkhaIWWMvJ6tJPH/ColpqGxMF0cnJcNeaRFjwv39yxpUTbg2 I9FWcgL7H5RsgU/BInIZUlbKyziq44S7GfI/RyCwOn1XdCuzSzcKcsBv4yBsOFPiz9Tq rVWgeMk/g4zYuFqPoi7RQLK1F6rImdvt0t5No= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=subject:from:reply-to:to:cc:in-reply-to:references:content-type :date:message-id:mime-version:x-mailer:content-transfer-encoding; b=otLd7obneEnh3sJdNL9TKojQtqgfL3ILxc4yt7uaq2zRxBwwlZkVvyfi9QhrhaRdte Bu+jQZOo/9lSlL4pZ1Gtpsy1B6KOWjRDpDrhhkFjsUvrWF0tRsL1O6DTzav3dGWB7lH0 67c8cOK6h56A4JXcNowc6c1X1DYTpqWpvWNtw= Received: by 10.103.92.10 with SMTP id u10mr570281mul.22.1233320004394; Fri, 30 Jan 2009 04:53:24 -0800 (PST) Received: from ?10.30.1.130? (vpn-or.studi-planet.com [78.47.172.52]) by mx.google.com with ESMTPS id i5sm1499484mue.46.2009.01.30.04.53.23 (version=SSLv3 cipher=RC4-MD5); Fri, 30 Jan 2009 04:53:23 -0800 (PST) From: Mister Olli To: Ivan Voras In-Reply-To: <9bbcef730901300214s19c91071vf9241cd7cd40ba57@mail.gmail.com> References: <87ocxp1tym.fsf@tabernacle.localnet> <1233285247.24925.4.camel@phoenix.blechhirn.net> <871vul1nqk.fsf@tabernacle.localnet> <9bbcef730901300214s19c91071vf9241cd7cd40ba57@mail.gmail.com> Content-Type: text/plain Date: Fri, 30 Jan 2009 13:52:47 +0100 Message-Id: <1233319967.24925.19.camel@phoenix.blechhirn.net> Mime-Version: 1.0 X-Mailer: Evolution 2.12.3 Content-Transfer-Encoding: 7bit Cc: freebsd-xen@freebsd.org, Julian Stecklina Subject: Re: kern.hz = 10 X-BeenThere: freebsd-xen@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: mister.olli@googlemail.com List-Id: Discussion of the freebsd port to xen - implementation and usage List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 30 Jan 2009 12:53:26 -0000 Hi, > Due to bad performance of high HZ in VMs, in 8-CURRENT it is > explicitly reduced to 10 if the kernel is running under any kind of > virtual environment. This is a somewhat theoretical number and > probably needs tuning. Oh I didn't knew that. *SORRY* > If you're interested in trying it out, you can increase it by adding > "kern.hz=xxx" to /boot/loader.conf and seeing what is the actual > performance influence of high HZ under Xen. I've run on 100HZ quite some time now and did have the impression that 8-CURRENT is slow. It's even faster on copy processes as 7 under VMware on a host machine which is 3 years younger... .. Mr. Olli