From: Michal Hocko <mhocko@xxxxxxxx> Subject: mm: do_swap_page(): fix up the error code do_swap_page() returns error codes from the VM_FAULT* space. try_charge() might return -ENOMEM, though, and then do_swap_page() simply returns 0 which means a success. We almost never return ENOMEM for GFP_KERNEL single page charge. Except for async OOM handling (oom_disabled v1). So this needs translation to VM_FAULT_OOM otherwise the the page fault path will not notify the userspace and wait for an action. Link: http://lkml.kernel.org/r/20200617090238.GL9499@xxxxxxxxxxxxxx Fixes: 4c6355b25e8b ("mm: memcontrol: charge swapin pages on instantiation") Signed-off-by: Michal Hocko <mhocko@xxxxxxxx> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx> Cc: Joonsoo Kim <js1304@xxxxxxxxx> Cc: Shakeel Butt <shakeelb@xxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: "Kirill A. Shutemov" <kirill@xxxxxxxxxxxxx> Cc: Roman Gushchin <guro@xxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memory.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/mm/memory.c~mm-do_swap_page-fix-up-the-error-code-instantiation +++ a/mm/memory.c @@ -3140,8 +3140,10 @@ vm_fault_t do_swap_page(struct vm_fault err = mem_cgroup_charge(page, vma->vm_mm, GFP_KERNEL); ClearPageSwapCache(page); - if (err) + if (err) { + ret = VM_FAULT_OOM; goto out_page; + } lru_cache_add(page); swap_readpage(page, true); _
