2022-10-21 16:56:05

by James Houghton

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

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 <[email protected]>
---
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