From: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Date: Thu, 6 Aug 2015 22:47:11 +0000 (-0700)
Subject: mm/memory-failure: set PageHWPoison before migrate_pages()
X-Git-Tag: v4.2-rc6~15^2~1
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=4491f71260;p=karo-tx-linux.git

mm/memory-failure: set PageHWPoison before migrate_pages()

Now page freeing code doesn't consider PageHWPoison as a bad page, so by
setting it before completing the page containment, we can prevent the
error page from being reused just after successful page migration.

I added TTU_IGNORE_HWPOISON for try_to_unmap() to make sure that the
page table entry is transformed into migration entry, not to hwpoison
entry.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Dean Nelson <dnelson@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index cd985530f102..ea5a93659488 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1659,6 +1659,8 @@ static int __soft_offline_page(struct page *page, int flags)
 		inc_zone_page_state(page, NR_ISOLATED_ANON +
 					page_is_file_cache(page));
 		list_add(&page->lru, &pagelist);
+		if (!TestSetPageHWPoison(page))
+			atomic_long_inc(&num_poisoned_pages);
 		ret = migrate_pages(&pagelist, new_page, NULL, MPOL_MF_MOVE_ALL,
 					MIGRATE_SYNC, MR_MEMORY_FAILURE);
 		if (ret) {
@@ -1673,9 +1675,8 @@ static int __soft_offline_page(struct page *page, int flags)
 				pfn, ret, page->flags);
 			if (ret > 0)
 				ret = -EIO;
-		} else {
-			if (!TestSetPageHWPoison(page))
-				atomic_long_inc(&num_poisoned_pages);
+			if (TestClearPageHWPoison(page))
+				atomic_long_dec(&num_poisoned_pages);
 		}
 	} else {
 		pr_info("soft offline: %#lx: isolation failed: %d, page count %d, type %lx\n",
diff --git a/mm/migrate.c b/mm/migrate.c
index f2415be7d93b..eb4267107d1f 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -880,7 +880,8 @@ static int __unmap_and_move(struct page *page, struct page *newpage,
 	/* Establish migration ptes or remove ptes */
 	if (page_mapped(page)) {
 		try_to_unmap(page,
-			TTU_MIGRATION|TTU_IGNORE_MLOCK|TTU_IGNORE_ACCESS);
+			TTU_MIGRATION|TTU_IGNORE_MLOCK|TTU_IGNORE_ACCESS|
+			TTU_IGNORE_HWPOISON);
 		page_was_mapped = 1;
 	}