Re: Preemptable Ticket Spinlock

[Jiannan Ouyang]

On Mon, Apr 22, 2013 at 4:44 PM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> On Mon, 2013-04-22 at 16:32 -0400, Rik van Riel wrote:
>>
>> IIRC one of the reasons was that the performance improvement wasn't
>> as obvious.  Rescheduling VCPUs takes a fair amount of time, quite
>> probably more than the typical hold time of a spinlock.
>
> IIRC it would spin for a while before blocking..
>
> /me goes re-read some of that thread...
>
> Ah, its because PLE is curing most of it.. !PLE it had huge gains but
> apparently nobody cares about !PLE hardware anymore :-)
>

For now, I don't know how good it can work with PLE. But I think it
should save the time of VMEXIT on PLE machine.
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