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Commit 9956edf3 authored by Hugh Dickins's avatar Hugh Dickins Committed by Linus Torvalds
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shmem: fix pageflags after swapping DMA32 object 

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: 800d8c63 ("shmem: add huge pages support")
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1611062003510.11253@eggly.anvils


Signed-off-by: default avatarHugh Dickins <hughd@google.com>
Acked-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org>	[4.8.x]
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 5e322bee

mm/shmem.c

+2 −0
Original line number Diff line number Diff line
@@ -1483,6 +1483,8 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp, 
	copy_highpage(newpage, oldpage);

	flush_dcache_page(newpage);



	__SetPageLocked(newpage);

	__SetPageSwapBacked(newpage);

	SetPageUptodate(newpage);

	set_page_private(newpage, swap_index);

	SetPageSwapCache(newpage);