tree a0b9167f2ffb54d44795574d4a0aa6e9bcf0e051
parent da1b13ccfbebe0b9d69b5d61eff0a675e19e69a5
author Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> 1441749809 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1441751728 -0700

mm/hwpoison: don't try to unpoison containment-failed pages

memory_failure() can be called at any page at any time, which means that
we can't eliminate the possibility of containment failure.  In such case
the best option is to leak the page intentionally (and never touch it
later.)

We have an unpoison function for testing, and it cannot handle such
containment-failed pages, which results in kernel panic (visible with
various calltraces.) So this patch suggests that we limit the
unpoisonable pages to properly contained pages and ignore any other
ones.

Testers are recommended to keep in mind that there're un-unpoisonable
pages when writing test programs.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Tested-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>