From owner-freebsd-xen@FreeBSD.ORG Fri Oct 30 09:30:47 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 7826E1065695 for ; Fri, 30 Oct 2009 09:30:47 +0000 (UTC) (envelope-from mister.olli@googlemail.com) Received: from mail-ew0-f209.google.com (mail-ew0-f209.google.com [209.85.219.209]) by mx1.freebsd.org (Postfix) with ESMTP id 077648FC18 for ; Fri, 30 Oct 2009 09:30:46 +0000 (UTC) Received: by ewy5 with SMTP id 5so819279ewy.37 for ; Fri, 30 Oct 2009 02:30:45 -0700 (PDT) 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=wx+bn2VdwRJj8os5zwSb+tvV6peQOcJ4GCSEuYabDvQ=; b=Tw7XEyu0eB5z4dG49HwbAobKbRg4xM7Uh0cJWa2Fsk9t/3lvlttDctqgNaexBrm4g4 pM8GsjzpuYAqp7eP3BNQT6qRin4Zf+O/D73LhArJeYVXvDfy8wdo7LUIvYDUxxXOx3YX CgTmD/Soor83Um4vKhVgNFu5VkdZsKnhXecow= 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=YkrQxnhVquSSLw/8muLjoUb8Kg9zGSYx4tFy545QIVxmGOMB03sp5/K/t72olLIAIa wnkVpd8czJMwi8k0FC52uVw2g7Ns1vGsaYU3Df0LjVzw5T6zer4fmLPYtO59bParokvK IueY7dQtjiohJkCUmmEAR8uKLWHN5NiPgQy0o= Received: by 10.210.15.14 with SMTP id 14mr125844ebo.49.1256895045619; Fri, 30 Oct 2009 02:30:45 -0700 (PDT) Received: from ?172.16.16.125? (dsl212102251105.4dsl.de [212.102.251.105]) by mx.google.com with ESMTPS id 10sm8234472eyz.3.2009.10.30.02.30.44 (version=SSLv3 cipher=RC4-MD5); Fri, 30 Oct 2009 02:30:44 -0700 (PDT) From: "Mr. Olli" To: Carsten Heesch In-Reply-To: References: Content-Type: text/plain Date: Fri, 30 Oct 2009 10:30:23 +0100 Message-Id: <1256895023.6479.42.camel@phoenix.blechhirn.net> Mime-Version: 1.0 X-Mailer: Evolution 2.26.3 Content-Transfer-Encoding: 7bit Cc: freebsd-xen@freebsd.org Subject: Re: SCHED_ULE vs SCHED_4BSD for XENHVM domU 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 Oct 2009 09:30:47 -0000 Hi, I compiled FreeBSD8-RC2 from SVN revision 198456 with the XEN config file left unchanged. the domU is 32bit. I'm running on SCHED_ULE and the system consumes <1% vCPU (according to xentop) in idle status. My dom0 is a gentoo linux 32-bit with 2x athlonMP 1900+ and 4GB ram. greetz, ---- Mr. Olli On Thu, 2009-10-29 at 23:12 +0000, Carsten Heesch wrote: > Hi guys, > > After FreeBSD 8.0-RC2 is working well (for me) on Xen 3.3.1, I somehow > made an interesting observation: > > Even if the FreeBSD domU does absolutely nothing, each of the assigned > vCPUs will be reported by xentop as using 15%-25% CPU time. It doesn't > matter, if domU is running with 1 or 4 vCPUs. All of them float at the > same level. > > On the same Xen box five other domU's (CentOS 5.2-5.4) have an idle > CPU percentage of 0 to 0.5%. > > So I played a bit and figured out that changing the scheduler in the > XENHVM kernel configuration from "option SCHED_ULE" to "option > SCHED_4BSD" resolves this problem. The idle state of the FreeBSD domU > is now identical to the CentOS domU's. > > However, this of course means using an old (maybe even deprecated?) > scheduler, which moreover isn't the best choice for multiple > (virtual) CPUs. > > The configuration I tested on is: > Intel i7 920 Quad-Core with Hyperthreading (8 logical CPUs) > Citrix XenServer 5.5 (based on CentOS 5.2, Xen 3.3.1) > > > Any thoughts, ideas, solutions? > > > Thanks! > > Carsten > > > > _______________________________________________ > freebsd-xen@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-xen > To unsubscribe, send any mail to "freebsd-xen-unsubscribe@freebsd.org"