+ mm-hwpoison-remove-recalculating-hpage.patch added to -mm tree

[akpm@linux-foundation.org]

The patch titled
     Subject: mm, hwpoison: remove recalculating hpage
has been added to the -mm tree.  Its filename is
     mm-hwpoison-remove-recalculating-hpage.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/mm-hwpoison-remove-recalculating-hpage.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/mm-hwpoison-remove-recalculating-hpage.patch

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------------------------------------------------------
From: Naoya Horiguchi <naoya.horiguchi@nec.com>
Subject: mm, hwpoison: remove recalculating hpage

hpage is never used after try_to_split_thp_page() in memory_failure(), so
we don't have to update hpage.  So let's not recalculate/use hpage.

Link: http://lkml.kernel.org/r/20200806184923.7007-3-nao.horiguchi@gmail.com
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Oscar Salvador <osalvador@suse.com>
Suggested-by: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Dmitry Yakunin <zeil@yandex-team.ru>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Qian Cai <cai@lca.pw>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/memory-failure.c |    6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

--- a/mm/memory-failure.c~mm-hwpoison-remove-recalculating-hpage
+++ a/mm/memory-failure.c
@@ -1342,7 +1342,6 @@ int memory_failure(unsigned long pfn, in
 		}
 		unlock_page(p);
 		VM_BUG_ON_PAGE(!page_count(p), p);
-		hpage = compound_head(p);
 	}
 
 	/*
@@ -1414,11 +1413,8 @@ int memory_failure(unsigned long pfn, in
 	/*
 	 * Now take care of user space mappings.
 	 * Abort on fail: __delete_from_page_cache() assumes unmapped page.
-	 *
-	 * When the raw error page is thp tail page, hpage points to the raw
-	 * page after thp split.
 	 */
-	if (!hwpoison_user_mappings(p, pfn, flags, &hpage)) {
+	if (!hwpoison_user_mappings(p, pfn, flags, &p)) {
 		action_result(pfn, MF_MSG_UNMAP_FAILED, MF_IGNORED);
 		res = -EBUSY;
 		goto out;
_

Patches currently in -mm which might be from naoya.horiguchi@nec.com are

mmhwpoison-cleanup-unused-pagehuge-check.patch
mm-hwpoison-remove-recalculating-hpage.patch
mmhwpoison-inject-dont-pin-for-hwpoison_filter.patch
mmhwpoison-introduce-mf_msg_unsplit_thp.patch
mmhwpoison-double-check-page-count-in-__get_any_page.patch