From 7851a45cd3f6198bf542c30e27b330e8eeb3736c Mon Sep 17 00:00:00 2001 From: Rik van Riel Date: Mon, 7 Oct 2013 11:29:23 +0100 Subject: [PATCH] mm: numa: Copy cpupid on page migration 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 Signed-off-by: Mel Gorman Cc: Andrea Arcangeli Cc: Johannes Weiner Cc: Srikar Dronamraju Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1381141781-10992-46-git-send-email-mgorman@suse.de Signed-off-by: Ingo Molnar --- mm/migrate.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/mm/migrate.c b/mm/migrate.c index ff537749d3b4..44c1fa9d6f54 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -443,6 +443,8 @@ 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 @@ -479,6 +481,13 @@ 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); /* -- 2.20.1