On Wed, 15 Apr 2015 07:25:46 +0000 Naoya Horiguchi <[email protected]>
wrote:
> Currently memory_failure() calls shake_page() to sweep pages out from pcplists
> only when the victim page is 4kB LRU page or thp head page. But we should do
> this for a thp tail page too.
> Consider that a memory error hits a thp tail page whose head page is on a
> pcplist when memory_failure() runs. Then, the current kernel skips
> shake_pages()
> part, so hwpoison_user_mappings() returns without calling split_huge_page()
> nor
> try_to_unmap() because PageLRU of the thp head is still cleared due to the
> skip
> of shake_page().
> As a result, me_huge_page() runs for the thp, which is a broken behavior.
>
> This patch fixes this problem by calling shake_page() for thp tail case.
>
> Fixes: 385de35722c9 ("thp: allow a hwpoisoned head page to be put back to
> LRU")
> Signed-off-by: Naoya Horiguchi <[email protected]>
> Cc: [email protected] # v3.4+
What are the userspace-visible effects of the bug? This info is needed
for backporting into -stable and other kernels, please.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
