Re: [PATCH] tiny MM performance and typo patches for 2.4.2

From: Rik van Riel (riel@conectiva.com.br)
Date: Mon Mar 05 2001 - 09:20:18 EST


On Mon, 5 Mar 2001, Mike Galbraith wrote:
> On Sun, 4 Mar 2001, Ulrich Kunitz wrote:
>
> > patch-uk2 makes use of the pgd, pmd and pte quicklists for x86 too;
> > risky: there might be a reason that 2.4.x doesn't use the
> > quicklists.
>
> I remember these being taken out (long ago), but not why. Anyone?

They probably wasted too much memory ...

Having _2_ quicklists per CPU (on SMP) is probably the way
to go: one with zeroed pages and one with non-zeroed pages.

This should avoid cache contention in __alloc_pages() and
also avoid unneeded zeroing of pages (when we put away a
zeroed page, eg. an freed pagetable page).

On UP we probably want a (smaller) freelist with zeroed
pages only, since that means we can keep more pages on the
inactive_clean list.

regards,

Rik

--
Virtual memory is like a game you can't win;
However, without VM there's truly nothing to lose...

http://www.surriel.com/ http://www.conectiva.com/ http://distro.conectiva.com.br/

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