Re: [PATCH 3/4] add ksm kernel shared memory driver

Izik Eidus
2008-11-11T23:03:39Z

Jonathan Corbet wrote:
>
> What about things like cache effects from scanning all those pages? My
> guess is that, if you're trying to run dozens of Windows guests, cache
> usage is not at the top of your list of concerns, but I could be
> wrong. Usually am...
>

Ok, ksm does make the cache of the cpu dirty when scanning the pages
(but the scanning happen slowly slowly and cache usually get dirty much
faster)
But infact it improve the cache by the fact that it make many ptes point
to the same page
so if before we had 12 process touching 12 diffrent physical page they
would dirty the page
but now they will touch just one...

so i guess it depend on how you see it...

> Thanks,
>
> jon
>