From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bin Ren Subject: Re: Re: IDLE domain is scheduled more than dom0 Date: Fri, 8 Jul 2005 20:06:41 +0100 Message-ID: <8ae780250507081206660c495f@mail.gmail.com> References: <571ACEFD467F7749BC50E0A98C17CDD8073C8586@pdsmsx403> <200507081133.02927.habanero@us.ibm.com> <200507081140.05185.habanero@us.ibm.com> Reply-To: bin.ren@cl.cam.ac.uk Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <200507081140.05185.habanero@us.ibm.com> Content-Disposition: inline List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Andrew Theurer Cc: Dan Magenheimer , xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org I think it's quite likely that by default SEDF doesn't allow domains to use slack CPU time, i.e. non work-conserving. Each domain is given an absolute percentage of the total CPU time. Try use command "xm sedf dom-id 0 0 0 1 0" to give a domain access to slack CPU time. Hopefully this could restore the performance. BTW, on my uniprocessor test machine with latest xen-unstable, xenlinux 2.6.11.12, domU sees significant drop in network throughputs (~40% less!) I'm interested in whether other people encounter similar situations, especially on SMP machines. Cheers, Bin On 7/8/05, Andrew Theurer wrote: > On Friday 08 July 2005 11:33, Andrew Theurer wrote: > > On Friday 08 July 2005 09:53, Dan Magenheimer wrote: > > > > Shouldn't IDLE domain not be scheduled for most time? Because > > > > idle task will call into PAL for power save on XEN/IA64, the > > > > performance is really, really bad to boot Dom0. The net effect is > > > > about ten times slower. After adding "sched=3Dbvt", everything back > > > > to normal. > > > > > > If the sedf scheduler is scheduling the idle domain when > > > domain0 is runnable, surely this is affecting performance > > > on x86 also and is a bug that should be fixed? > > > > > > Has anyone done any performance testing (on x86) since > > > sedf was checked in as the default? > > > > Just tried launching some cpu bound tasks in dom0, and I get only 75% > > cpu util for dom0. I'll try the other domain scheduler and see if it > > clears it up. >=20 > OK, just confirmed bvt works as expected in ia32. >=20 > -Andrew >=20 > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel >