Messages in this thread | | | Date | Mon, 20 Apr 2015 14:30:14 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] mm/memory-failure: call shake_page() when error hits thp tail page |
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On Wed, 15 Apr 2015 07:25:46 +0000 Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> 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 <n-horiguchi@ah.jp.nec.com> > Cc: stable@vger.kernel.org # v3.4+
What are the userspace-visible effects of the bug? This info is needed for backporting into -stable and other kernels, please.
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