Re: reverse pte lookups and anonymous private mappings; avl trees?

[Rik van Riel <H.H.vanRiel@fys.ruu.nl>]

On Wed, 4 Mar 1998, Stephen C. Tweedie wrote:

> > +#define PgQ_Locked	0	/* page is unswappable - mlock()'d */
> > +#define PgQ_Active	1	/* page is mapped and active -> young */
> > +#define PgQ_Inactive	2	/* page is mapped, but hasn't been referenced recently -> old */
> > +#define PgQ_Swappable	3	/* page has no mappings, is dirty */
> > +#define PgQ_Swapping	4	/* page is being swapped */
> > +#define PgQ_Dumpable	5	/* page has no mappings, is not dirty, but is still in the page cache */
> 
> don't seem to give us all that much extra, since we probably never want
> to go out and explicitly search for all pages on such lists.  (That's
> assuming that the page aging and swapping scanner is working by walking
> pages in physical address order, not by traversing any other lists.)

We just might want to do that. If we can _guarantee_
a certain number of free+(inactive&clean) pages, we
can keep the number of free pages lower, and we can
keep more pages longer in memory, giving more speed
to the overall system.

Rik.
+-----------------------------+------------------------------+
| For Linux mm-patches, go to | "I'm busy managing memory.." |
| my homepage (via LinuxHQ).  | H.H.vanRiel@fys.ruu.nl       |
| ...submissions welcome...   | http://www.fys.ruu.nl/~riel/ |
+-----------------------------+------------------------------+