On Fri 20-05-16 15:19:12, Vlastimil Babka wrote:
> On 05/20/2016 03:06 PM, Michal Hocko wrote:
[...]
> > Why don't we need also to count also retries?
>
> We could, but not like you suggest.
>
> > ---
> > diff --git a/mm/migrate.c b/mm/migrate.c
> > index 53ab6398e7a2..ef9c5211ae3c 100644
> > --- a/mm/migrate.c
> > +++ b/mm/migrate.c
> > @@ -1190,9 +1190,9 @@ int migrate_pages(struct list_head *from, new_page_t
> > get_new_page,
> > }
> > }
> > }
> > +out:
> > nr_failed += retry;
> > rc = nr_failed;
>
> This overwrites rc == -ENOMEM, which at least compaction needs to recognize.
> But we could duplicate "nr_failed += retry" in the case -ENOMEM.
Right you are. So we should do
---
diff --git a/mm/migrate.c b/mm/migrate.c
index 53ab6398e7a2..123fed94022b 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1171,6 +1171,7 @@ int migrate_pages(struct list_head *from, new_page_t
get_new_page,
switch(rc) {
case -ENOMEM:
+ nr_failed += retry + 1;
goto out;
case -EAGAIN:
retry++;
--
Michal Hocko
SUSE Labs
