Re: [Engine-devel] CPU Pinning @engine

From: "Doron Fediuck" <dfediuck(a)redhat.com&gt; To: dlaor(a)redhat.com Cc: engine-devel(a)ovirt.org Sent: Sunday, May 20, 2012 5:49:08 PM Subject: Re: [Engine-devel] CPU Pinning @engine On 20/05/12 21:41, Dor Laor wrote: > On 05/17/2012 11:15 PM, Doron Fediuck wrote: >> On 17/05/12 20:28, Ayal Baron wrote: >>> "Live migration will not be supported for such VM's." >>> >>> Migration will work on homogeneous clusters so this should not be >>> enforced (not limited to VMs which are pinned to host) just give >>> a warning. >>> >> I agree, but if we wish to ping vCPUx to pCPUy in host a, we >> cannot ensure to have the same in host b, >> since it may have pCPUy too busy, so performance will degrade. >> Also, I hope you saw my general comment > > Performance may degrade on any migration to loaded host regardless > of pinning. > > There is not need to forbid migration. Instead, the SLA assurance > policy should verify the dedicated resources and match the target > w/ the guarantee and decide according to this. > Thanks for the input. We may start with migration blocked in a configurable manner, so people who wish migrate to work will simply set the relevant configuration key. As for looking for a matched CPU, will add it as p2.

>> about starting with a humble solution and gradually improving. In >> this context (auto)numa can help us, >> so we better do numa than handle migration for basic mode, risking >> performance issues. >> >>> >>> ----- Original Message ----- >>>> From: "Doron Fediuck&quot;&lt;dfediuck(a)redhat.com&gt; >>>> To: engine-devel(a)ovirt.org >>>> Sent: Thursday, May 17, 2012 2:42:46 PM >>>> Subject: [Engine-devel] CPU Pinning @engine >>>> >>>> Hi All, >>>> Currently the VDSM has a CPU pinning hook. >>>> We'd like to add better support of it into the engine itself. >>>> Here's a design draft to cover it: >>>> http://www.ovirt.org/wiki/Features/Design/cpu-pinning >>>> >>>> Please review and comment if needed. >>>> >>>> Thanks! >>>> -- >>>> >>>> /d >>>> >>>> Never say "OOPS!" always say "Ah, Interesting!" >>>> _______________________________________________ >>>> Engine-devel mailing list >>>> Engine-devel(a)ovirt.org >>>> http://lists.ovirt.org/mailman/listinfo/engine-devel >>>> >>> _______________________________________________ >>> Engine-devel mailing list >>> Engine-devel(a)ovirt.org >>> http://lists.ovirt.org/mailman/listinfo/engine-devel >> >> > -- /d Never say "OOPS!" always say "Ah, Interesting!" _______________________________________________ Engine-devel mailing list Engine-devel(a)ovirt.org http://lists.ovirt.org/mailman/listinfo/engine-devel