Re: [RFC PATCH 3/10] define page_file_cache

From: Christoph Lameter
Date: Wed Nov 07 2007 - 13:18:57 EST


On Wed, 7 Nov 2007, Rik van Riel wrote:

> On Wed, 7 Nov 2007 10:06:10 -0800 (PST)
> Christoph Lameter <clameter@xxxxxxx> wrote:
>
> > On Wed, 7 Nov 2007, Rik van Riel wrote:
> >
> > > How exactly can an anonymous page ever become file backed?
> >
> > When they get assigned a swap entry.
>
> That does not change their status. They're still swap backed.

If they are swap backed then they have a backing store on disk. They are
file backed in some sense.

> > > > Do ramfs pages count as memory backed?
> > >
> > > Since ramfs pages cannot be evicted from memory at all, they
> > > should go into the "noreclaim" page set.
> >
> > Which LRU do they go on.
>
> With the patch set from last weekend, the file LRU.

Argh.

> With the patch set later this week, they'll be in the
> "noreclaim" page set, which is never scanned by the VM.

That sounds better.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/