Re: [PATCH] shmem: fix pageflags after swapping DMA32 object

From	"Kirill A. Shutemov" <kirill@shutemov.name>
Newsgroups	linux.kernel
Subject	Re: [PATCH] shmem: fix pageflags after swapping DMA32 object
Date	2016-11-07 12:40 +0100
Message-ID	<sAQro-2rT-7@gated-at.bofh.it> (permalink)
References	<sAJpT-6m8-7@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Sun, Nov 06, 2016 at 08:08:29PM -0800, Hugh Dickins wrote:
> 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>

Sorry for that.

Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>

-- 
 Kirill A. Shutemov

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[PATCH] shmem: fix pageflags after swapping DMA32 object Hugh Dickins <hughd@google.com> - 2016-11-07 05:10 +0100
  Re: [PATCH] shmem: fix pageflags after swapping DMA32 object "Kirill A. Shutemov" <kirill@shutemov.name> - 2016-11-07 12:40 +0100

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