From 9a1656f1d19b815c8a11216b753118974987a390 Mon Sep 17 00:00:00 2001 From: Ralph Campbell Date: Tue, 13 Oct 2020 16:53:13 -0700 Subject: [PATCH] mm/memcg: fix device private memcg accounting [ Upstream commit 9a137153fc8798a89d8fce895cd0a06ea5b8e37c ] The code in mc_handle_swap_pte() checks for non_swap_entry() and returns NULL before checking is_device_private_entry() so device private pages are never handled. Fix this by checking for non_swap_entry() after handling device private swap PTEs. I assume the memory cgroup accounting would be off somehow when moving a process to another memory cgroup. Currently, the device private page is charged like a normal anonymous page when allocated and is uncharged when the page is freed so I think that path is OK. Signed-off-by: Ralph Campbell Signed-off-by: Andrew Morton Acked-by: Johannes Weiner Cc: Michal Hocko Cc: Vladimir Davydov Cc: Jerome Glisse Cc: Balbir Singh Cc: Ira Weiny Link: https://lkml.kernel.org/r/20201009215952.2726-1-rcampbell@nvidia.com xFixes: c733a82874a7 ("mm/memcontrol: support MEMORY_DEVICE_PRIVATE") Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- mm/memcontrol.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index ca1632850fb7..edf98f8588ee 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5398,7 +5398,7 @@ static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, struct page *page = NULL; swp_entry_t ent = pte_to_swp_entry(ptent); - if (!(mc.flags & MOVE_ANON) || non_swap_entry(ent)) + if (!(mc.flags & MOVE_ANON)) return NULL; /* @@ -5417,6 +5417,9 @@ static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, return page; } + if (non_swap_entry(ent)) + return NULL; + /* * Because lookup_swap_cache() updates some statistics counter, * we call find_get_page() with swapper_space directly.