Re: page_add/remove_rmap costs

[Rik van Riel <riel@conectiva.com.br>]

On Wed, 24 Jul 2002, Andrew Morton wrote:
> Rik van Riel wrote:
> > On Wed, 24 Jul 2002, Andrew Morton wrote:
> >
> > I guess I'll take a stab at bcrl's and davem's code and will
> > try to also hide it between an rmap.c interface ;)
>
> hmm, OK.  Big job...

Absolutely, not a short term thing.  In the short term
I'll split out the remainder of Craig Kulesa's big patch
and will send you bits and pieces.

> > > For example: given that copy_page_range performs atomic ops against
> > > page->count, how come page_add_rmap()'s atomic op against page->flags
> > > is more of a problem?
> >
> > Could it have something to do with cpu_relax() delaying
> > things ?
>
> Don't think so.  That's only executed on the contended case,

You're right.

regards,

Rik
-- 
Bravely reimplemented by the knights who say "NIH".

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