Re: [PATCH 1/1] KVM: x86: avoid unnecessary bitmap allocation when memslot is clean

[Avi Kivity <avi@redhat.com>]

On 04/27/2010 04:46 PM, Takuya Yoshikawa wrote:
> (2010/04/27 22:18), Avi Kivity wrote:
>
>>> Furthermore, the reduced allocations seem to produce good effects for
>>> other cases too. Actually, I observed that the time for the ioctl was
>>> more stable than the original one and the average time for dirty slots
>>> was also reduced by some extent.
>>
>> Can you explain why the dirty slots were improved?
>
> I cannot do exactly, but vmalloc() might affect the following 
> allocations?
>
> But actually, I could check how much one vmalloc() consumed our time,
> and this will be completely removed by our "moving dirty bitmaps to 
> user space".
>
>
> Better to remove this explanation about dirty slots?

I guess so.

>
> BTW, maybe good news for us!
>
> 1. I found one place in which set_bit_to_user() is locally defined using
> current helpers.

Interesting, where?

-- 
error compiling committee.c: too many arguments to function