Re: [Engine-devel] CPU Pinning @engine

On 21/05/12 01:45, Andrew Cathrow wrote: > > > ----- Original Message ----- >> From: "Doron Fediuck"<dfediuck(a)redhat.com> >> 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. > > We shouldn't block migration > If a user wants to not migrate a cpu pinned VM then let them use the non-migratable flag in the UI. > We're not blocking migration, we're allowing pinning (for now) only for non-migrative VM's. For p2 we'll verify destination host has the relevant pinning capacity, which will allow pinning for migrative VM's as well.

> >> >>>> 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"<dfediuck(a)redhat.com> >>>>>> 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 >>