On Tue, 2010-02-23 at 15:32 +0100, Johannes Weiner wrote:
> Hello Minchan,
>
> On Tue, Feb 23, 2010 at 11:03:20PM +0900, Minchan Kim wrote:
> > On Mon, 2010-02-22 at 20:49 +0100, Johannes Weiner wrote:
> > > Protecting file pages that are not by themselves mapped but are part
> > > of a mapped file is also a historic leftover for short-lived things
> >
> > I have been a question in the part.
> > You seem to solve my long question. :)
> > But I want to make sure it by any log.
> > Could you tell me where I find the discussion mail thread or git log at
> > that time?
>
> I dug up this change in history.git, but unfortunately it was merged
> undocumented in a large changeset. So there does not seem to be any
> written reason for why this was merged initially. What I wrote is
> based on what Rik told me on IRC.
>
> > > /* Reclaim if clean, defer dirty pages to writeback */
> > > @@ -1378,7 +1357,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
> > > }
> > >
> > > /* page_referenced clears PageReferenced */
> > > - if (page_mapping_inuse(page) &&
> > > + if (page_mapped(page) &&
> > > page_referenced(page, 0, sc->mem_cgroup, &vm_flags)) {
> > > nr_rotated++;
> > > /*
> >
> > It's good to me.
> > But page_referenced already have been checked page_mapped.
> > How about folding alone page_mapped check into page_referenced's inner?
>
> The next patch essentially does that. page_referenced() will no longer
> clear PG_referenced on the page and if page_referenced() is true, it
> means that young ptes were found and the page must thus be mapped.
>
> So #3 removes the page_mapped() from this conditional.
Thanks!
I should have reviewed your [3/3] before nitpick.
>
> Hannes
--
Kind regards,
Minchan Kim
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxxx For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>