diff mbox series

[stable,5.10,v2,1/2] mm: hwpoison: remove the unnecessary THP check

Message ID 20211104210752.390351-1-shy828301@gmail.com (mailing list archive)
State New
Headers show
Series [stable,5.10,v2,1/2] mm: hwpoison: remove the unnecessary THP check | expand

Commit Message

Yang Shi Nov. 4, 2021, 9:07 p.m. UTC
commit c7cb42e94473aafe553c0f2a3d8ca904599399ed upstream.

When handling THP hwpoison checked if the THP is in allocation or free
stage since hwpoison may mistreat it as hugetlb page.  After commit
415c64c1453a ("mm/memory-failure: split thp earlier in memory error
handling") the problem has been fixed, so this check is no longer
needed.  Remove it.  The side effect of the removal is hwpoison may
report unsplit THP instead of unknown error for shmem THP.  It seems not
like a big deal.

The following patch "mm: filemap: check if THP has hwpoisoned subpage
for PMD page fault" depends on this, which fixes shmem THP with
hwpoisoned subpage(s) are mapped PMD wrongly.  So this patch needs to be
backported to -stable as well.

Link: https://lkml.kernel.org/r/20211020210755.23964-2-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Suggested-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 mm/memory-failure.c | 14 --------------
 1 file changed, 14 deletions(-)

Comments

Greg Kroah-Hartman Nov. 8, 2021, 8:06 a.m. UTC | #1
On Thu, Nov 04, 2021 at 02:07:51PM -0700, Yang Shi wrote:
> commit c7cb42e94473aafe553c0f2a3d8ca904599399ed upstream.
> 
> When handling THP hwpoison checked if the THP is in allocation or free
> stage since hwpoison may mistreat it as hugetlb page.  After commit
> 415c64c1453a ("mm/memory-failure: split thp earlier in memory error
> handling") the problem has been fixed, so this check is no longer
> needed.  Remove it.  The side effect of the removal is hwpoison may
> report unsplit THP instead of unknown error for shmem THP.  It seems not
> like a big deal.
> 
> The following patch "mm: filemap: check if THP has hwpoisoned subpage
> for PMD page fault" depends on this, which fixes shmem THP with
> hwpoisoned subpage(s) are mapped PMD wrongly.  So this patch needs to be
> backported to -stable as well.
> 
> Link: https://lkml.kernel.org/r/20211020210755.23964-2-shy828301@gmail.com
> Signed-off-by: Yang Shi <shy828301@gmail.com>
> Suggested-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
> Cc: Hugh Dickins <hughd@google.com>
> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Cc: Matthew Wilcox <willy@infradead.org>
> Cc: Oscar Salvador <osalvador@suse.de>
> Cc: Peter Xu <peterx@redhat.com>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
> ---
>  mm/memory-failure.c | 14 --------------
>  1 file changed, 14 deletions(-)
> 
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 01445ddff58d..bd2cd4dd59b6 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -956,20 +956,6 @@ static int get_hwpoison_page(struct page *page)
>  {
>  	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;
> -- 
> 2.26.2
> 

Thanks, both now queued up.

greg k-h
diff mbox series

Patch

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 01445ddff58d..bd2cd4dd59b6 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -956,20 +956,6 @@  static int get_hwpoison_page(struct page *page)
 {
 	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;