From 37f9f5595c26d3cb644ca2fab83dc4c4db119f9f Mon Sep 17 00:00:00 2001
From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Date: Tue, 26 Jul 2016 15:25:48 -0700
Subject: [PATCH] thp: run vma_adjust_trans_huge() outside i_mmap_rwsem
vma_addjust_trans_huge() splits pmd if it's crossing VMA boundary.
During split we munlock the huge page which requires rmap walk. rmap
wants to take the lock on its own.
Let's move vma_adjust_trans_huge() outside i_mmap_rwsem to fix this.
Link: http://lkml.kernel.org/r/1466021202-61880-19-git-send-email-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/mmap.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index 234edffec1d07..31f9b2220b723 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -675,6 +675,8 @@ again: remove_next = 1 + (end > next->vm_end);
}
}
+ vma_adjust_trans_huge(vma, start, end, adjust_next);
+
if (file) {
mapping = file->f_mapping;
root = &mapping->i_mmap;
@@ -695,8 +697,6 @@ again: remove_next = 1 + (end > next->vm_end);
}
}
- vma_adjust_trans_huge(vma, start, end, adjust_next);
-
anon_vma = vma->anon_vma;
if (!anon_vma && adjust_next)
anon_vma = next->anon_vma;
--
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