From 43fbdeb349640e3d763f0eb52b6aef92d4e2ec17 Mon Sep 17 00:00:00 2001 From: Ralph Campbell Date: Mon, 14 Dec 2020 19:05:55 -0800 Subject: [PATCH] mm: handle zone device pages in release_pages() release_pages() is an optimized, inlined version of __put_pages() except that zone device struct pages that are not page_is_devmap_managed() (i.e., memory_type MEMORY_DEVICE_GENERIC and MEMORY_DEVICE_PCI_P2PDMA), fall through to the code that could return the zone device page to the page allocator instead of adjusting the pgmap reference count. Clearly these type of pages are not having the reference count decremented to zero via release_pages() or page allocation problems would be seen. Just to be safe, handle the 1 to zero case in release_pages() like __put_page() does. Link: https://lkml.kernel.org/r/20201021194733.11530-1-rcampbell@nvidia.com Signed-off-by: Ralph Campbell Reviewed-by: Christoph Hellwig Cc: Jerome Glisse Cc: John Hubbard Cc: Alistair Popple Cc: Jason Gunthorpe Cc: Dan Williams Cc: Matthew Wilcox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/swap.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/swap.c b/mm/swap.c index 47a47681c86b..29220174433b 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -909,6 +909,9 @@ void release_pages(struct page **pages, int nr) put_devmap_managed_page(page); continue; } + if (put_page_testzero(page)) + put_dev_pagemap(page->pgmap); + continue; } if (!put_page_testzero(page)) -- 2.11.0