From mboxrd@z Thu Jan 1 00:00:00 1970 From: Juergen Gross Subject: Re: [BUG] mistakenly wake in Xen's credit scheduler Date: Wed, 28 Oct 2015 07:01:06 +0100 Message-ID: <563064A2.5060903@suse.com> References: <1446011672.2937.288.camel@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1446011672.2937.288.camel@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Dario Faggioli , suokun , George Dunlap Cc: xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On 10/28/2015 06:54 AM, Dario Faggioli wrote: > On Tue, 2015-10-27 at 14:11 -0600, suokun wrote: >> On Tue, Oct 27, 2015 at 3:44 AM, George Dunlap >> wrote: >>> On Tue, Oct 27, 2015 at 5:59 AM, suokun >>> wrote: > >> Thank you for your reply. I have test credit2 this morning. The I/O >> performance is correct, however, the CPU accounting seems not >> correct. >> Here is my experiment on credit2: >> >> VM-IO: 1-vCPU pinned to a pCPU, running netperf >> VM-CPU: 1-vCPU pinned the the same pCPU, running a while(1) loop >> The throughput of netperf is the same(941Mbps) as VM-IO runs alone. >> >> However, when I use xl top to show the VM CPU utilization, VM-IO >> takes >> 73% of CPU time and VM-CPU takes 99% CPU time. Their sum is more than >> 100%. I doubt it is due to the CPU utilization accounting in credit2 >> scheduler. >> > Yeah, well, sorry, but even if we both (me and George) encouraged you > to try Credit2, that wasn't a great idea. :-( In fact, you're using > pinning for this test, and Credit2 does not have pinning (yet)! :-P > > That explains why utilizations are summing up to higher than 100%: > vCPUs are just not being confined to one processor. > > Pinning for Credit2 is just around the corner. Let's try this again > when it will be there, ok? :-D Or try it in a cpupool with just one pcpu? Juergen