From 0efadf48bca01f17cb64ebceaf528590b2bc7665 Mon Sep 17 00:00:00 2001 From: Yisheng Xie Date: Fri, 24 Feb 2017 14:57:39 -0800 Subject: mm/hotplug: enable memory hotplug for non-lru movable pages We had considered all of the non-lru pages as unmovable before commit bda807d44454 ("mm: migrate: support non-lru movable page migration"). But now some of non-lru pages like zsmalloc, virtio-balloon pages also become movable. So we can offline such blocks by using non-lru page migration. This patch straightforwardly adds non-lru migration code, which means adding non-lru related code to the functions which scan over pfn and collect pages to be migrated and isolate them before migration. Signed-off-by: Yisheng Xie Cc: Michal Hocko Cc: Minchan Kim Cc: Naoya Horiguchi Cc: Vlastimil Babka Cc: Andi Kleen Cc: Hanjun Guo Cc: Johannes Weiner Cc: Joonsoo Kim Cc: Mel Gorman Cc: Reza Arbab Cc: Taku Izumi Cc: Vitaly Kuznetsov Cc: Xishi Qiu Cc: Yisheng Xie Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 41985aa4672d..2d34cdb70f1d 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -7227,8 +7227,9 @@ void *__init alloc_large_system_hash(const char *tablename, * If @count is not zero, it is okay to include less @count unmovable pages * * PageLRU check without isolation or lru_lock could race so that - * MIGRATE_MOVABLE block might include unmovable pages. It means you can't - * expect this function should be exact. + * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable + * check without lock_page also may miss some movable non-lru pages at + * race condition. So you can't expect this function should be exact. */ bool has_unmovable_pages(struct zone *zone, struct page *page, int count, bool skip_hwpoisoned_pages) @@ -7284,6 +7285,9 @@ bool has_unmovable_pages(struct zone *zone, struct page *page, int count, if (skip_hwpoisoned_pages && PageHWPoison(page)) continue; + if (__PageMovable(page)) + continue; + if (!PageLRU(page)) found++; /* -- cgit v1.2.1