[Engine-devel] CPU Pinning @engine

[Doron Fediuck]

On 21/05/12 01:45, Andrew Cathrow wrote:
> 
> 
> ----- Original Message -----
>> From: "Doron Fediuck" <dfediuck at redhat.com>
>> To: dlaor at redhat.com
>> Cc: engine-devel at 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 at redhat.com>
>>>>>> To: engine-devel at 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!"
>>>>>> _______________________________________________
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>>>>>>
>>>>> _______________________________________________
>>>>> Engine-devel mailing list
>>>>> Engine-devel at ovirt.org
>>>>> http://lists.ovirt.org/mailman/listinfo/engine-devel
>>>>
>>>>
>>>
>>
>>
>> --
>>
>> /d
>>
>> Never say "OOPS!" always say "Ah, Interesting!"
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-- 

/d

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