On Wed, Feb 10, 2021 at 01:17:33PM +0100, Vlastimil Babka wrote: > AFAICS, at the time page migration used putback_lru_page() to release the > migration source page. This would put the page on lru pvec even if it was in > fact not mapped anywhere anymore, and only the drain would actually free it. > Seems Minchan optimized this in 2016 by c6c919eb90e0 ("mm: use put_page() to > free page instead of putback_lru_page()") Ok, I see. Thanks for this valuable information Vlastimil. -- Oscar Salvador SUSE L3