Hi, Yosry, Yosry Ahmed <yosryahmed@xxxxxxxxxx> writes: > This reverts commit c3096e6782b733158bf34f6bbb4567808d4e0740. > > That commit made sure we immediately add the new page to the LRU before > remove_migration_ptes() is called in migrate_move_folio() (used to be > __unmap_and_move() back then), such that the rmap walk will rebuild the > correct mlock_count for the page again. This was needed because the > mlock_count was lost when the page is isolated. This is no longer the > case since mlock_count no longer overlays page->lru. > > Revert the commit (the code was foliated afterward the commit, so the > revert is updated as such). > > Signed-off-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx> > --- > mm/migrate.c | 24 +++++++++--------------- > 1 file changed, 9 insertions(+), 15 deletions(-) > > diff --git a/mm/migrate.c b/mm/migrate.c > index 01cac26a3127..68f693731865 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -1279,19 +1279,6 @@ static int migrate_folio_move(free_page_t put_new_page, unsigned long private, > if (unlikely(!is_lru)) > goto out_unlock_both; The patch itself looks good to me! Thanks! Reviewed-by: "Huang, Ying" <ying.huang@xxxxxxxxx> And, it seems that we can remove the above 2 lines and "out_unlock_both" label now. That can make the code simpler a little. Right? Best Regards, Huang, Ying > - /* > - * When successful, push dst to LRU immediately: so that if it > - * turns out to be an mlocked page, remove_migration_ptes() will > - * automatically build up the correct dst->mlock_count for it. > - * > - * We would like to do something similar for the old page, when > - * unsuccessful, and other cases when a page has been temporarily > - * isolated from the unevictable LRU: but this case is the easiest. > - */ > - folio_add_lru(dst); > - if (page_was_mapped) > - lru_add_drain(); > - > if (page_was_mapped) > remove_migration_ptes(src, dst, false); > > @@ -1301,9 +1288,16 @@ static int migrate_folio_move(free_page_t put_new_page, unsigned long private, > /* > * If migration is successful, decrease refcount of dst, > * which will not free the page because new page owner increased > - * refcounter. > + * refcounter. As well, if it is LRU folio, add the folio to LRU > + * list in here. Use the old state of the isolated source folio to > + * determine if we migrated a LRU folio. dst was already unlocked > + * and possibly modified by its owner - don't rely on the folio > + * state. > */ > - folio_put(dst); > + if (unlikely(!is_lru)) > + folio_put(dst); > + else > + folio_putback_lru(dst); > > /* > * A folio that has been migrated has all references removed
