From: Ralph Campbell <rcampb...@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 <rcampb...@nvidia.com> Signed-off-by: Andrew Morton <a...@linux-foundation.org> Acked-by: Johannes Weiner <han...@cmpxchg.org> Cc: Michal Hocko <mho...@kernel.org> Cc: Vladimir Davydov <vdavydov....@gmail.com> Cc: Jerome Glisse <jgli...@redhat.com> Cc: Balbir Singh <bsinghar...@gmail.com> Cc: Ira Weiny <ira.we...@intel.com> Link: https://lkml.kernel.org/r/20201009215952.2726-1-rcampb...@nvidia.com xFixes: c733a82874a7 ("mm/memcontrol: support MEMORY_DEVICE_PRIVATE") Signed-off-by: Linus Torvalds <torva...@linux-foundation.org> Signed-off-by: Sasha Levin <sas...@kernel.org> --- mm/memcontrol.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 13f559af1ab6a..6795bdf662566 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5276,7 +5276,7 @@ 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; /* @@ -5295,6 +5295,9 @@ 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
