Re: Problem in Page Cache Replacement

Fengguang Wu
2012-11-22T19:06:51Z

On Wed, Nov 21, 2012 at 12:07:22PM +0200, Metin Döşlü wrote:
> On Wed, Nov 21, 2012 at 12:00 PM, Jaegeuk Hanse <jaegeuk.hanse@gmail.com> wrote:
> >
> > On 11/21/2012 05:58 PM, metin d wrote:
> >
> > Hi Fengguang,
> >
> > I run tests and attached the results. The line below I guess shows the data-1 page caches.
> >
> > 0x000000080000006c 6584051 25718 __RU_lA___________________P________ referenced,uptodate,lru,active,private
> >
> >
> > I thinks this is just one state of page cache pages.
>
> But why these page caches are in this state as opposed to other page
> caches. From the results I conclude that:
>
> data-1 pages are in state : referenced,uptodate,lru,active,private

I wonder if it's this code that stops data-1 pages from being
reclaimed:

shrink_page_list():

if (page_has_private(page)) {
if (!try_to_release_page(page, sc->gfp_mask))
goto activate_locked;

What's the filesystem used?

> data-2 pages are in state : referenced,uptodate,lru,mappedtodisk

Thanks,
Fengguang