thp: fix unsuitable behavior for hwpoisoned tail page
authorJin Dongming <jin.dongming@np.css.fujitsu.com>
Tue, 1 Feb 2011 23:52:41 +0000 (15:52 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 3 Feb 2011 00:03:19 +0000 (16:03 -0800)
commitaf241a083404acda7ba3690e5b7697949d729fcc
treef299ac844b38bc9a82e1477d8ef16648898f5584
parenta6d30dddae4648837be5a0c0cb2c0ae9ad0377db
thp: fix unsuitable behavior for hwpoisoned tail page

When a tail page of THP is poisoned, memory-failure will do nothing except
setting PG_hwpoison, while the expected behavior is that the process, who
is using the poisoned tail page, should be killed.

The above problem is caused by lru check of the poisoned tail page of THP.
Because PG_lru flag is only set on the head page of THP, the check always
consider the poisoned tail page as NON lru page.

So the lru check for the tail page of THP should be avoided, as like as
hugetlb.

This patch adds !PageTransCompound() before lru check for THP, because of
the check (!PageHuge() && !PageTransCompound()) the whole branch could be
optimized away at build time when both hugetlbfs and THP are set with "N"
(or in archs not supporting either of those).

[akpm@linux-foundation.org: fix unrelated typo in shake_page() comment]
Signed-off-by: Jin Dongming <jin.dongming@np.css.fujitsu.com>
Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/memory-failure.c