From 3abef4e6c23feef4aa9ab161ae138d6d39ae69f3 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Fri, 22 Feb 2013 16:34:27 -0800 Subject: [PATCH] mm: numa: take THP into account when migrating pages for NUMA balancing Wanpeng Li pointed out that numamigrate_isolate_page() assumes that only one base page is being migrated when in fact it can also be checking THP. The consequences are that a migration will be attempted when a target node is nearly full and fail later. It's unlikely to be user-visible but it should be fixed. While we are there, migrate_balanced_pgdat() should treat nr_migrate_pages as an unsigned long as it is treated as a watermark. Signed-off-by: Mel Gorman Suggested-by: Wanpeng Li Cc: Peter Zijlstra Cc: Andrea Arcangeli Cc: Ingo Molnar Cc: Simon Jeons Cc: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/migrate.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/mm/migrate.c b/mm/migrate.c index 2fd8b4af4744..77f4e70df24d 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1461,7 +1461,7 @@ int migrate_vmas(struct mm_struct *mm, const nodemask_t *to, * pages. Currently it only checks the watermarks which crude */ static bool migrate_balanced_pgdat(struct pglist_data *pgdat, - int nr_migrate_pages) + unsigned long nr_migrate_pages) { int z; for (z = pgdat->nr_zones - 1; z >= 0; z--) { @@ -1559,8 +1559,10 @@ int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page) { int ret = 0; + VM_BUG_ON(compound_order(page) && !PageTransHuge(page)); + /* Avoid migrating to a node that is nearly full */ - if (migrate_balanced_pgdat(pgdat, 1)) { + if (migrate_balanced_pgdat(pgdat, 1UL << compound_order(page))) { int page_lru; if (isolate_lru_page(page)) { -- GitLab