[RFC PATCH v2 23/47] rmap: update hugetlb lock comment for HGM

[James Houghton]

The VMA lock is used to prevent high-granularity HugeTLB mappings from
being collapsed while other threads are doing high-granularity page
table walks.

Signed-off-by: James Houghton <jthoughton@xxxxxxxxxx>
---
 mm/rmap.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/rmap.c b/mm/rmap.c
index 19850d955aea..527463c1e936 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -47,7 +47,8 @@
  *
  * hugetlbfs PageHuge() take locks in this order:
  *   hugetlb_fault_mutex (hugetlbfs specific page fault mutex)
- *     vma_lock (hugetlb specific lock for pmd_sharing)
+ *     vma_lock (hugetlb specific lock for pmd_sharing and high-granularity
+ *               mapping)
  *       mapping->i_mmap_rwsem (also used for hugetlb pmd sharing)
  *         page->flags PG_locked (lock_page)
  */
-- 
2.38.0.135.g90850a2211-goog