diff options
| author | Alexandru Moise <00moses.alexander00@gmail.com> | 2017-10-03 16:14:31 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-10-12 11:56:12 +0200 |
| commit | 67109577bb95105cebc55b6323ec016f6f5d0e34 (patch) | |
| tree | cbeb5b6b7f204fe1de36cc322e0597fbc25c140b | |
| parent | d288d663393f17d9b0c1c1e82274be594bbaa187 (diff) | |
mm, hugetlb, soft_offline: save compound page order before page migration
commit 19bfbe22f59a207417b2679e7e83c180419c9ec5 upstream.
This fixes a bug in madvise() where if you'd try to soft offline a
hugepage via madvise(), while walking the address range you'd end up,
using the wrong page offset due to attempting to get the compound order
of a former but presently not compound page, due to dissolving the huge
page (since commit c3114a84f7f9: "mm: hugetlb: soft-offline: dissolve
source hugepage after successful migration").
As a result I ended up with all my free pages except one being offlined.
Link: http://lkml.kernel.org/r/20170912204306.GA12053@gmail.com
Fixes: c3114a84f7f9 ("mm: hugetlb: soft-offline: dissolve source hugepage after successful migration")
Signed-off-by: Alexandru Moise <00moses.alexander00@gmail.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | mm/madvise.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/mm/madvise.c b/mm/madvise.c index 4d7d1e5ddba9..4edca1d86339 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -614,18 +614,26 @@ static int madvise_inject_error(int behavior, { struct page *page; struct zone *zone; + unsigned int order; if (!capable(CAP_SYS_ADMIN)) return -EPERM; - for (; start < end; start += PAGE_SIZE << - compound_order(compound_head(page))) { + + for (; start < end; start += PAGE_SIZE << order) { int ret; ret = get_user_pages_fast(start, 1, 0, &page); if (ret != 1) return ret; + /* + * When soft offlining hugepages, after migrating the page + * we dissolve it, therefore in the second loop "page" will + * no longer be a compound page, and order will be 0. + */ + order = compound_order(compound_head(page)); + if (PageHWPoison(page)) { put_page(page); continue; |