Re: [PATCH 1/6] mm: migration: Factor out code to compute expected number of page references

Jan Kara
2018-12-17T13:11:05Z

On Fri 14-12-18 16:24:28, Mel Gorman wrote:
> On Fri, Dec 14, 2018 at 04:53:11PM +0100, Jan Kara wrote:
> > > This page->mapping test is relevant for the "Anonymous page without
> > > mapping" check but I think it's wrong. An anonymous page without mapping
> > > doesn't have a NULL mapping, it sets PAGE_MAPPING_ANON and the field can
> > > be special in other ways. I think you meant to use page_mapping(page)
> > > here, not page->mapping?
> >
> > Yes, that's a bug. It should have been page_mapping(page). Thanks for
> > catching this.
> >
>
> My pleasure, should have spotted it the first time around :/

And after fixing this, I can see the success rates for
global-dhp__workload_thpscale-madvhugepage to go back to the original
values. So that was indeed the problem. I'll send the fixup to Andrew.

Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR