| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.14 083/191] mm/memcg: fix device private memcg accounting | Date | Tue, 27 Oct 2020 14:48:58 +0100 |
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From: Ralph Campbell <rcampbell@nvidia.com>
[ 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 <rcampbell@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Ira Weiny <ira.weiny@intel.com> 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 <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- mm/memcontrol.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 5cbcd4b81bf8f..70707d44a6903 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4514,7 +4514,7 @@ 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; /* @@ -4533,6 +4533,9 @@ 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. -- 2.25.1
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