From: Rik van Riel <[email protected]> After page migration, the new page has the nidpid unset. This makes every fault on a recently migrated page look like a first numa fault, leading to another page migration.
Copying over the nidpid at page migration time should prevent erroneous migrations of recently migrated pages. Signed-off-by: Rik van Riel <[email protected]> Signed-off-by: Mel Gorman <[email protected]> --- mm/migrate.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/mm/migrate.c b/mm/migrate.c index 6ff845f..1e1dbc9 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -439,6 +439,8 @@ int migrate_huge_page_move_mapping(struct address_space *mapping, */ void migrate_page_copy(struct page *newpage, struct page *page) { + int cpupid; + if (PageHuge(page) || PageTransHuge(page)) copy_huge_page(newpage, page); else @@ -475,6 +477,13 @@ void migrate_page_copy(struct page *newpage, struct page *page) __set_page_dirty_nobuffers(newpage); } + /* + * Copy NUMA information to the new page, to prevent over-eager + * future migrations of this same page. + */ + cpupid = page_cpupid_xchg_last(page, -1); + page_cpupid_xchg_last(newpage, cpupid); + mlock_migrate_page(newpage, page); ksm_migrate_page(newpage, page); /* -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
