From 4d75136be8bf3ae01b0bc3e725b2cdc921e103bd Mon Sep 17 00:00:00 2001
From: Jane Chu <jane.chu@oracle.com>
Date: Thu, 29 Apr 2021 23:02:19 -0700
Subject: [PATCH] mm/memory-failure: unnecessary amount of unmapping
Git-commit: 4d75136be8bf3ae01b0bc3e725b2cdc921e103bd
Patch-mainline: v5.13-rc1
References: bsc#1189640

It appears that unmap_mapping_range() actually takes a 'size' as its third
argument rather than a location, the current calling fashion causes
unnecessary amount of unmapping to occur.

Link: https://lkml.kernel.org/r/20210420002821.2749748-1-jane.chu@oracle.com
Fixes: 6100e34b2526e ("mm, memory_failure: Teach memory_failure() about dev_pagemap pages")
Signed-off-by: Jane Chu <jane.chu@oracle.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Jan Kara <jack@suse.cz>

---
 mm/memory-failure.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1236,7 +1236,7 @@ static int memory_failure_dev_pagemap(un
 		 * communicated in siginfo, see kill_proc()
 		 */
 		start = (page->index << PAGE_SHIFT) & ~(size - 1);
-		unmap_mapping_range(page->mapping, start, start + size, 0);
+		unmap_mapping_range(page->mapping, start, size, 0);
 	}
 	kill_procs(&tokill, flags & MF_MUST_KILL, trapno, !unmap_success, pfn,
 		   flags);