The patch titled
Subject: mm, hwpoison: enable error handling on shmem thp
has been added to the -mm tree. Its filename is
mm-hwpoison-enable-error-handling-on-shmem-thp.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-hwpoison-enable-error-handling-on-shmem-thp.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-hwpoison-enable-error-handling-on-shmem-thp.patch
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------------------------------------------------------
From: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
Subject: mm, hwpoison: enable error handling on shmem thp
Currently hwpoison code checks PageAnon() for thp and refuses to handle
errors on non-anonymous thps (just for historical reason). We now support
non-anonymou thp like shmem one, so this patch suggests to enable to
handle shmem thps. Fortunately, we already have can_split_huge_page() to
check if a give thp is splittable, so this patch relies on it.
Link: https://lkml.kernel.org/r/20210209062128.453814-1-nao.horiguchi@xxxxxxxxx
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory-failure.c | 34 +++++++++-------------------------
1 file changed, 9 insertions(+), 25 deletions(-)
--- a/mm/memory-failure.c~mm-hwpoison-enable-error-handling-on-shmem-thp
+++ a/mm/memory-failure.c
@@ -959,20 +959,6 @@ static int __get_hwpoison_page(struct pa
{
struct page *head = compound_head(page);
- if (!PageHuge(head) && PageTransHuge(head)) {
- /*
- * Non anonymous thp exists only in allocation/free time. We
- * can't handle such a case correctly, so let's give it up.
- * This should be better than triggering BUG_ON when kernel
- * tries to touch the "partially handled" page.
- */
- if (!PageAnon(head)) {
- pr_err("Memory failure: %#lx: non anonymous thp\n",
- page_to_pfn(page));
- return 0;
- }
- }
-
if (get_page_unless_zero(head)) {
if (head == compound_head(page))
return 1;
@@ -1200,21 +1186,19 @@ static int identify_page_state(unsigned
static int try_to_split_thp_page(struct page *page, const char *msg)
{
- lock_page(page);
- if (!PageAnon(page) || unlikely(split_huge_page(page))) {
- unsigned long pfn = page_to_pfn(page);
+ struct page *head;
+ lock_page(page);
+ head = compound_head(page);
+ if (PageTransHuge(head) && can_split_huge_page(head, NULL) &&
+ !split_huge_page(page)) {
unlock_page(page);
- if (!PageAnon(page))
- pr_info("%s: %#lx: non anonymous thp\n", msg, pfn);
- else
- pr_info("%s: %#lx: thp split failed\n", msg, pfn);
- put_page(page);
- return -EBUSY;
+ return 0;
}
+ pr_info("%s: %#lx: thp split failed\n", msg, page_to_pfn(page));
unlock_page(page);
-
- return 0;
+ put_page(page);
+ return -EBUSY;
}
static int memory_failure_hugetlb(unsigned long pfn, int flags)
_
Patches currently in -mm which might be from naoya.horiguchi@xxxxxxx are
mm-hwpoison-do-not-lock-page-again-when-me_huge_page-successfully-recovers.patch
mm-hwpoison-enable-error-handling-on-shmem-thp.patch
