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From:   Jane Chu <jane.chu@oracle.com>
To:     naoya.horiguchi@nec.com, dan.j.williams@intel.com,
        dave.jiang@intel.com, akpm@linux-foundation.org,
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Cc:     Jane Chu <jane.chu@oracle.com>
Subject: [PATCH] mm/memory-failure: unecessary amount of unmapping
Date:   Mon, 19 Apr 2021 18:28:21 -0600
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It appears that unmap_mapping_range() actually takes a 'size' as its
third argument rather than a location, the current calling fashion
causes unecessary amount of unmapping to occur.

Fixes: 6100e34b2526e ("mm, memory_failure: Teach memory_failure() about dev_pagemap pages")
Signed-off-by: Jane Chu <jane.chu@oracle.com>
---
 mm/memory-failure.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index f7ed9559d494..85ad98c00fd9 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1368,7 +1368,7 @@ static int memory_failure_dev_pagemap(unsigned long pfn, int flags,
 		 * 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, !unmap_success, pfn, flags);
 	rc = 0;
-- 
2.18.4