Re: [MM] Remove rss batching from copy_page_range()

Andi Kleen
2009-11-05T08:27:38Z

On Wed, Nov 04, 2009 at 05:02:12PM -0500, Christoph Lameter wrote:
> On Wed, 4 Nov 2009, Andi Kleen wrote:
>
> > > With per cpu counters in mm there is no need for batching
> > > mm counter updates anymore. Update counters directly while
> > > copying pages.
> >
> > Hmm, but with all the inlining with some luck the local
> > counters will be in registers. That will never be the case
> > with the per cpu counters.
>
> The function is too big for that to occur and the counters have to be

If it's only called once then gcc doesn't care about size.

> preserved across function calls. The code is shorter with the patch
> applied:

I see. Thanks for the data.

-Andi