On Wed, Mar 17, 2021 at 03:05:40PM +0100, Michal Hocko wrote:

That being said, bailing out early makes sense to me. But now that
you've made me look into the migrate_pages excellent error state reporting
I suspect we have a bug here. Note the 
"Returns the number of pages that were not migrated, or an error code."

but I do not see putback_movable_pages for ret > 0 so it seems we might
leak some pages.

I fell for the same thing when looking at that code.
It took a while until I realized what was really going on.

quoted

Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Vlastimil Babka <redacted>
Reviewed-by: David Hildenbrand <redacted>

The patch itself looks reasonable but make sure to mention this is mere
cosmetic change unless there is a real problem fixed by this.
Acked-by: Michal Hocko <mhocko@suse.com>

What about appending the following in the changelog:

"Note that this is not fixing a real issue, just a cosmetic change. Although
 we can save some cycles by backing off ealier."


-- 
Oscar Salvador
SUSE L3