Re: [PATCH 3/3] Eliminate read_cr3 on TLB flush

Zachary Amsden
2007-05-31T08:27:55Z

Avi Kivity wrote:
> Anthony Liguori wrote:
>>>>
>>> For KVM, it should be okay as well. But we can replace two CR4 accesses
>>> with just one hypercall.
>>>
>>
>> I was thinking the same thing :-)
>>
>> I was actually thinking about adding a hypercall to set/clear a bit
>> in a control register. The thought here is that it would be useful
>> not just for the global bit but also for CR0.TS although we would
>> need another paravirt_op hook for stts.
>>
>
> Are global tlb flushes frequent enough to warrant optimization?

Not very, unless you have a most unusual workload on 32-bit with highmem
and suffer from kmap exhaustion.

Zach