Messages in this thread Patch in this message | | | Date | Sun, 6 Nov 2016 20:08:29 -0800 (PST) | From | Hugh Dickins <> | Subject | [PATCH] shmem: fix pageflags after swapping DMA32 object |
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If shmem_alloc_page() does not set PageLocked and PageSwapBacked, then shmem_replace_page() needs to do so for itself. Without this, it puts newpage on the wrong lru, re-unlocks the unlocked newpage, and system descends into "Bad page" reports and freeze; or if CONFIG_DEBUG_VM=y, it hits an earlier VM_BUG_ON_PAGE(!PageLocked), depending on config.
But shmem_replace_page() is not a common path: it's only called when swapin (or swapoff) finds the page was already read into an unsuitable zone: usually all zones are suitable, but gem objects for a few drm devices (gma500, omapdrm, crestline, broadwater) require zone DMA32 if there's more than 4GB of ram.
Fixes: 800d8c63b2e9 ("shmem: add huge pages support") Cc: stable@vger.kernel.org # v4.8 Signed-off-by: Hugh Dickins <hughd@google.com> ---
mm/shmem.c | 2 ++ 1 file changed, 2 insertions(+)
--- 4.9-rc4/mm/shmem.c 2016-10-15 12:52:13.157533478 -0700 +++ linux/mm/shmem.c 2016-11-06 12:45:49.626193769 -0800 @@ -1483,6 +1483,8 @@ static int shmem_replace_page(struct pag copy_highpage(newpage, oldpage); flush_dcache_page(newpage); + __SetPageLocked(newpage); + __SetPageSwapBacked(newpage); SetPageUptodate(newpage); set_page_private(newpage, swap_index); SetPageSwapCache(newpage);
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