Re: [PATCH 0/4] KVM: Dirty logging optimization using rmap

[Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>]

(2011/11/14 19:25), Avi Kivity wrote:
> On 11/14/2011 11:20 AM, Takuya Yoshikawa wrote:
>> This is a revised version of my previous work.  I hope that
>> the patches are more self explanatory than before.
>>
>
> It looks good.  I'll let Marcelo (or anyone else?) review it as well
> before applying.
>
> Do you have performance measurements?
>

For VGA, 30-40us became 3-5us when the display was quiet, with a
enough warmed up guest.

Near the criterion, the number was not different much from the
original version.

For live migration, I forgot the number but the result was good.
But my test case was not enough to cover every pattern, so I changed
the criterion to be a bit conservative.

	More tests may be able to find a better criterion.
	I am not in a hurry about this, so it is OK to add some tests
	before merging this.

But what I did not like was holding spin lock more than 100us or so
with the original version.  With this version, at least, the problem
should be cured some.

	Takuya


One note:

kvm-unit-tests' dirty logging test was broken for 32-bit box: compile error.
I changed an "idt" to "boot_idt" and used it.

I do not know kvm-unit-tests well, so I want somebody to fix that officially.