diff options
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 4ae77db917f2..c2052e9a6ef6 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1753,13 +1753,25 @@ static void unreserve_highatomic_pageblock(const struct alloc_context *ac) struct page, lru); /* - * It should never happen but changes to locking could - * inadvertently allow a per-cpu drain to add pages - * to MIGRATE_HIGHATOMIC while unreserving so be safe - * and watch for underflows. + * In page freeing path, migratetype change is racy so + * we can counter several free pages in a pageblock + * in this loop althoug we changed the pageblock type + * from highatomic to ac->migratetype. So we should + * adjust the count once. */ - zone->nr_reserved_highatomic -= min(pageblock_nr_pages, - zone->nr_reserved_highatomic); + if (get_pageblock_migratetype(page) == + MIGRATE_HIGHATOMIC) { + /* + * It should never happen but changes to + * locking could inadvertently allow a per-cpu + * drain to add pages to MIGRATE_HIGHATOMIC + * while unreserving so be safe and watch for + * underflows. + */ + zone->nr_reserved_highatomic -= min( + pageblock_nr_pages, + zone->nr_reserved_highatomic); + } /* * Convert to ac->migratetype and avoid the normal |