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Commit d950b958 authored by Naoya Horiguchi's avatar Naoya Horiguchi Committed by Andi Kleen
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HWPOISON, hugetlb: soft offlining for hugepage 



This patch extends soft offlining framework to support hugepage.
When memory corrected errors occur repeatedly on a hugepage,
we can choose to stop using it by migrating data onto another hugepage
and disabling the original (maybe half-broken) one.

ChangeLog since v4:
- branch soft_offline_page() for hugepage

ChangeLog since v3:
- remove comment about "ToDo: hugepage soft-offline"

ChangeLog since v2:
- move refcount handling into isolate_lru_page()

ChangeLog since v1:
- add double check in isolating hwpoisoned hugepage
- define free/non-free checker for hugepage
- postpone calling put_page() for hugepage in soft_offline_page()

Signed-off-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: default avatarJun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: default avatarMel Gorman <mel@csn.ul.ie>
Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
parent 8c6c2ecb

mm/memory-failure.c

+55 −4
Original line number Diff line number Diff line
@@ -693,8 +693,6 @@ static int me_swapcache_clean(struct page *p, unsigned long pfn) 
 * Issues:

 * - Error on hugepage is contained in hugepage unit (not in raw page unit.)

 *   To narrow down kill region to one page, we need to break up pmd.

 * - To support soft-offlining for hugepage, we need to support hugepage

 *   migration.

 */

static int me_huge_page(struct page *p, unsigned long pfn)

{
@@ -1220,6 +1218,10 @@ EXPORT_SYMBOL(unpoison_memory); 
static struct page *new_page(struct page *p, unsigned long private, int **x)

{

	int nid = page_to_nid(p);

	if (PageHuge(p))

		return alloc_huge_page_node(page_hstate(compound_head(p)),

						   nid);

	else

		return alloc_pages_exact_node(nid, GFP_HIGHUSER_MOVABLE, 0);

}
@@ -1248,8 +1250,15 @@ static int get_any_page(struct page *p, unsigned long pfn, int flags) 
	 * was free.

	 */

	set_migratetype_isolate(p);

	/*

	 * When the target page is a free hugepage, just remove it

	 * from free hugepage list.

	 */

	if (!get_page_unless_zero(compound_head(p))) {

		if (is_free_buddy_page(p)) {

		if (PageHuge(p)) {

			pr_debug("get_any_page: %#lx free huge page\n", pfn);

			ret = dequeue_hwpoisoned_huge_page(compound_head(p));

		} else if (is_free_buddy_page(p)) {

			pr_debug("get_any_page: %#lx free buddy page\n", pfn);

			/* Set hwpoison bit while page is still isolated */

			SetPageHWPoison(p);
@@ -1268,6 +1277,45 @@ static int get_any_page(struct page *p, unsigned long pfn, int flags) 
	return ret;

}



static int soft_offline_huge_page(struct page *page, int flags)

{

	int ret;

	unsigned long pfn = page_to_pfn(page);

	struct page *hpage = compound_head(page);

	LIST_HEAD(pagelist);



	ret = get_any_page(page, pfn, flags);

	if (ret < 0)

		return ret;

	if (ret == 0)

		goto done;



	if (PageHWPoison(hpage)) {

		put_page(hpage);

		pr_debug("soft offline: %#lx hugepage already poisoned\n", pfn);

		return -EBUSY;

	}



	/* Keep page count to indicate a given hugepage is isolated. */



	list_add(&hpage->lru, &pagelist);

	ret = migrate_huge_pages(&pagelist, new_page, MPOL_MF_MOVE_ALL, 0);

	if (ret) {

		pr_debug("soft offline: %#lx: migration failed %d, type %lx\n",

			 pfn, ret, page->flags);

		if (ret > 0)

			ret = -EIO;

		return ret;

	}

done:

	if (!PageHWPoison(hpage))

		atomic_long_add(1 << compound_order(hpage), &mce_bad_pages);

	set_page_hwpoison_huge_page(hpage);

	dequeue_hwpoisoned_huge_page(hpage);

	/* keep elevated page count for bad page */

	return ret;

}



/**

 * soft_offline_page - Soft offline a page.

 * @page: page to offline
@@ -1295,6 +1343,9 @@ int soft_offline_page(struct page *page, int flags) 
	int ret;

	unsigned long pfn = page_to_pfn(page);



	if (PageHuge(page))

		return soft_offline_huge_page(page, flags);



	ret = get_any_page(page, pfn, flags);

	if (ret < 0)

		return ret;