On Mon, 17 Sep 2001, Jan Harkes wrote:
> On Mon, Sep 17, 2001 at 02:33:12PM +0200, Daniel Phillips wrote:
> > The inactive queues have always had both mapped and unmapped pages on
> > them. The reason for unmapping a swap cache page page when putting it
>
> So the following code in refill_inactive_scan only exists in my
> imagination?
>
> if (page_count(page) <= (page->buffers ? 2 : 1)) {
> deactivate_page_nolock(page);
No, but I agree with Daniel that it's wrong.
The reason it exists there is because the current inactive_clean list
scanning doesn't have any pressure into VM scanning, so if we'd let mapped
pages on the inactive queue, then reclaim_page() would be unhappy about
them.
That can be solved several ways:
- like we do now. Hackish and wrong, but kind-of-works.
- make reclaim_page() have the ability to do vm scanning pressure (ie if
it starts noticing that there are too many mapped pages on the reclaim
list, it should cause VM scan)
- physical maps
Actually, now that I look at it, the lack of de-activation actually hurts
page_launder() - which doesn't get to launder pages that are still mapped
(even though getting rid of buffers from them would almost certainly be
good under memory pressure).
Linus
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This archive was generated by hypermail 2b29 : Sun Sep 23 2001 - 21:00:20 EST