tree 82dcfddae57bc34c04be1b044b363534082d8ada
parent a9869b837c098732bad84939015c0eb391b23e41
author Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> 1283908778 +0900
committer Andi Kleen <ak@linux.intel.com> 1286523165 +0200

HWPOSION, hugetlb: recover from free hugepage error when !MF_COUNT_INCREASED

Currently error recovery for free hugepage works only for MF_COUNT_INCREASED.
This patch enables !MF_COUNT_INCREASED case.

Free hugepages can be handled directly by alloc_huge_page() and
dequeue_hwpoisoned_huge_page(), and both of them are protected
by hugetlb_lock, so there is no race between them.

Note that this patch defines the refcount of HWPoisoned hugepage
dequeued from freelist is 1, deviated from present 0, thereby we
can avoid race between unpoison and memory failure on free hugepage.
This is reasonable because unlikely to free buddy pages, free hugepage
is governed by hugetlbfs even after error handling finishes.
And it also makes unpoison code added in the later patch cleaner.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andi Kleen <ak@linux.intel.com>