From 3abef4e6c23feef4aa9ab161ae138d6d39ae69f3 Mon Sep 17 00:00:00 2001
From: Mel Gorman <mgorman@suse.de>
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 <mgorman@suse.de>
Suggested-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Simon Jeons <simon.jeons@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
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)) {
--
2.34.1