From 3f2eb0287ebd62ec8d6d544f830285302279e6bf Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= Date: Tue, 3 Oct 2017 16:14:57 -0700 Subject: [PATCH] mm/memcg: avoid page count check for zone device MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Fix for 4.14, zone device page always have an elevated refcount of one and thus page count sanity check in uncharge_page() is inappropriate for them. [mhocko@suse.com: nano-optimize VM_BUG_ON in uncharge_page] Link: http://lkml.kernel.org/r/20170914190011.5217-1-jglisse@redhat.com Signed-off-by: Jérôme Glisse Signed-off-by: Michal Hocko Reported-by: Evgeny Baskakov Acked-by: Michal Hocko Cc: Johannes Weiner Cc: Vladimir Davydov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 696c6529e900..d5f3a62887cf 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5658,7 +5658,8 @@ static void uncharge_batch(const struct uncharge_gather *ug) static void uncharge_page(struct page *page, struct uncharge_gather *ug) { VM_BUG_ON_PAGE(PageLRU(page), page); - VM_BUG_ON_PAGE(!PageHWPoison(page) && page_count(page), page); + VM_BUG_ON_PAGE(page_count(page) && !is_zone_device_page(page) && + !PageHWPoison(page) , page); if (!page->mem_cgroup) return;