Re: [PATCH 01/11] mm/page_isolation: prefer the node of the source page

From: Joonsoo Kim
Date: Wed May 20 2020 - 21:18:58 EST


2020ë 5ì 21ì (ë) ìì 9:37, Roman Gushchin <guro@xxxxxx>ëì ìì:
>
> On Mon, May 18, 2020 at 10:20:47AM +0900, js1304@xxxxxxxxx wrote:
> > From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
> >
> > For locality, it's better to migrate the page to the same node
> > rather than the node of the current caller's cpu.
> >
> > Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
>
> Acked-by: Roman Gushchin <guro@xxxxxx>

Thanks for review!

> > ---
> > mm/page_isolation.c | 4 +++-
> > 1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/mm/page_isolation.c b/mm/page_isolation.c
> > index 2c11a38..7df89bd 100644
> > --- a/mm/page_isolation.c
> > +++ b/mm/page_isolation.c
> > @@ -300,5 +300,7 @@ int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn,
> >
> > struct page *alloc_migrate_target(struct page *page, unsigned long private)
> > {
> > - return new_page_nodemask(page, numa_node_id(), &node_states[N_MEMORY]);
> > + int nid = page_to_nid(page);
> > +
> > + return new_page_nodemask(page, nid, &node_states[N_MEMORY]);
>
> Why not new_page_nodemask(page, page_to_nid(page), &node_states[N_MEMORY]) ?
> Still fits into 80 characters.

It's just my preference not directly using function call in argument
as much as possible.
If you don't like it, I will change it as you suggested. However,
since alloc_migrate_target()
will be removed in following patch, there will be no difference in the end.

Thanks.