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authorMel Gorman <mgorman@suse.de>2013-02-22 16:34:27 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-02-23 17:50:16 -0800
commit3abef4e6c23feef4aa9ab161ae138d6d39ae69f3 (patch)
treeaf0648448caa7715fca89ba78c9bca606a1d9e74 /mm/migrate.c
parent34f0315adb58af3b01f59d05b2bce267474e71cb (diff)
downloadlwn-3abef4e6c23feef4aa9ab161ae138d6d39ae69f3.tar.gz
lwn-3abef4e6c23feef4aa9ab161ae138d6d39ae69f3.zip
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>
Diffstat (limited to 'mm/migrate.c')
-rw-r--r--mm/migrate.c6
1 files 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)) {