From owner-freebsd-xen@FreeBSD.ORG Fri Oct 30 18:17:25 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 82BAD1065670 for ; Fri, 30 Oct 2009 18:17:25 +0000 (UTC) (envelope-from danilobaio@gmail.com) Received: from mail-bw0-f213.google.com (mail-bw0-f213.google.com [209.85.218.213]) by mx1.freebsd.org (Postfix) with ESMTP id 81D158FC17 for ; Fri, 30 Oct 2009 18:17:24 +0000 (UTC) Received: by bwz5 with SMTP id 5so3897437bwz.3 for ; Fri, 30 Oct 2009 11:17:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type; bh=nG5jFdEf6w+4agQDuQRY1QIkuXtGGN3+sfsVfjYTgjY=; b=GRsWC5phZBcnWJ2jL59RRss2Ij5wvm2D31VYH8NCXPP67o4x5bPVhb07qGdkAGfCnq 936Lam4GcALV5spNRYmNwzBuBrKB707DBsRxqPzDhlq+ADKpErs71fSkRRkbnxMgkymf 76RlCtxa/FRSxZSFc3H+gs1fktpUEF4nRlF0w= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=N/YwymNa0Ie+ob5bxmhgIcJ2LgMJbglxxdDufEdb83SRfcIDtGPRCQzGnG3cDjQhGC ogwm17JTOjgT/AU2BjTXmVdfhUN//Y4wrnQj5JDz9VAFB76pM+VMs0YKaSWN4a8yMiYP sdX120y//vpOPFoCint3g++Z1tHe77K4THvyk= MIME-Version: 1.0 Received: by 10.204.154.207 with SMTP id p15mr1287392bkw.202.1256925054145; Fri, 30 Oct 2009 10:50:54 -0700 (PDT) In-Reply-To: References: Date: Fri, 30 Oct 2009 15:50:53 -0200 Message-ID: <5b9854910910301050j3d6d3ab8h5e9b35227b58304@mail.gmail.com> From: Danilo Baio To: freebsd-xen@freebsd.org Content-Type: multipart/mixed; boundary=0015174795725c964604772aab8a X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Subject: Re: SCHED_ULE vs SCHED_4BSD for XENHVM domU X-BeenThere: freebsd-xen@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list 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 18:17:25 -0000 --0015174795725c964604772aab8a Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On Thu, Oct 29, 2009 at 9:12 PM, Carsten Heesch wrote: > Hi guys, > > After FreeBSD 8.0-RC2 is working well (for me) on Xen 3.3.1, I somehow ma= de > 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 sa= me > 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 XENH= VM > kernel configuration from "option SCHED_ULE" to "option SCHED_4BSD" resol= ves > 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 > > Hi, Same thing here. I've build 8.0-RC2 amd64 with kernel XENHVM for testing with a XenServer 5.0.0 that i have here. Only the memory information don't appear on the console of xencenter. And the processor 14% of use all the time. After build with SCHED_4BSD, 3% usage CPU. AMD64 - XENHVM freeba8# uname -a FreeBSD freeba8.localdomain 8.0-RC2 FreeBSD 8.0-RC2 #0: Fri Oct 30 15:18:43 BRST 2009 root@freeba8.localdomain:/usr/obj/usr/src/sys/XENHVM amd64 XenServer 5.0.0 (CentOS) Xen 3.2 Regards. --=20 Danilo Gon=E7alves Baio (dbaio) danilobaio (*) gmail . com +55 (44) 8801 1257 --0015174795725c964604772aab8a--