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.

Suggested-by: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Aristeu Rozanski <aris@ruivo.org>
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: Oscar Salvador <osalvador@suse.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20200922135650.1634-3-osalvador@suse.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 484f968..6876757 100644 (file)
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1341,7 +1341,6 @@ int memory_failure(unsigned long pfn, int flags)
                }
                unlock_page(p);
                VM_BUG_ON_PAGE(!page_count(p), p);
-               hpage = compound_head(p);
        }
 
        /*
@@ -1413,11 +1412,8 @@ int memory_failure(unsigned long pfn, int flags)
        /*
         * 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;