thp: change pmd_trans_huge_lock() interface to return ptl
After THP refcounting rework we have only two possible return values
from pmd_trans_huge_lock(): success and failure. Return-by-pointer for
ptl doesn't make much sense in this case.
Let's convert pmd_trans_huge_lock() to return ptl on success and NULL on
failure.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Minchan Kim <minchan@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/mincore.c b/mm/mincore.c
index 2a565ed..563f320 100644
--- a/mm/mincore.c
+++ b/mm/mincore.c
@@ -117,7 +117,8 @@
unsigned char *vec = walk->private;
int nr = (end - addr) >> PAGE_SHIFT;
- if (pmd_trans_huge_lock(pmd, vma, &ptl)) {
+ ptl = pmd_trans_huge_lock(pmd, vma);
+ if (ptl) {
memset(vec, 1, nr);
spin_unlock(ptl);
goto out;