diff options
| author | Xishi Qiu <qiuxishi@huawei.com> | 2014-02-14 10:33:35 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-02-20 11:06:12 -0800 |
| commit | 6843d9254c8cd2decb30edaf7deffaad4d244c51 (patch) | |
| tree | dffc1779a7aef3aeb8128d2daa0ec5cd40527e32 | |
| parent | 2d9258e499abbbe55fb60a26995e378f2b51d513 (diff) | |
mm: fix process accidentally killed by mce because of huge page migration
Based on c8721bbbdd36382de51cd6b7a56322e0acca2414 upstream, but only the
bugfix portion pulled out.
Hi Naoya or Greg,
We found a bug in 3.10.x.
The problem is that we accidentally have a hwpoisoned hugepage in free
hugepage list. It could happend in the the following scenario:
process A process B
migrate_huge_page
put_page (old hugepage)
linked to free hugepage list
hugetlb_fault
hugetlb_no_page
alloc_huge_page
dequeue_huge_page_vma
dequeue_huge_page_node
(steal hwpoisoned hugepage)
set_page_hwpoison_huge_page
dequeue_hwpoisoned_huge_page
(fail to dequeue)
I tested this bug, one process keeps allocating huge page, and I
use sysfs interface to soft offline a huge page, then received:
"MCE: Killing UCP:2717 due to hardware memory corruption fault at 8200034"
Upstream kernel is free from this bug because of these two commits:
f15bdfa802bfa5eb6b4b5a241b97ec9fa1204a35
mm/memory-failure.c: fix memory leak in successful soft offlining
c8721bbbdd36382de51cd6b7a56322e0acca2414
mm: memory-hotplug: enable memory hotplug to handle hugepage
The first one, although the problem is about memory leak, this patch
moves unset_migratetype_isolate(), which is important to avoid the race.
The latter is not a bug fix and it's too big, so I rewrite a small one.
The following patch can fix this bug.(please apply f15bdfa802bf first)
Signed-off-by: Xishi Qiu <qiuxishi@huawei.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | mm/hugetlb.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 40ad2c6e0ca..aa3b9a63394 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -21,6 +21,7 @@ #include <linux/rmap.h> #include <linux/swap.h> #include <linux/swapops.h> +#include <linux/page-isolation.h> #include <asm/page.h> #include <asm/pgtable.h> @@ -517,9 +518,15 @@ static struct page *dequeue_huge_page_node(struct hstate *h, int nid) { struct page *page; - if (list_empty(&h->hugepage_freelists[nid])) + list_for_each_entry(page, &h->hugepage_freelists[nid], lru) + if (!is_migrate_isolate_page(page)) + break; + /* + * if 'non-isolated free hugepage' not found on the list, + * the allocation fails. + */ + if (&h->hugepage_freelists[nid] == &page->lru) return NULL; - page = list_entry(h->hugepage_freelists[nid].next, struct page, lru); list_move(&page->lru, &h->hugepage_activelist); set_page_refcounted(page); h->free_huge_pages--; |