[PATCH] __unmap_hugepage_range(): add comment
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index a088f59..f7355bf 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -365,6 +365,11 @@
pte_t pte;
struct page *page;
struct page *tmp;
+ /*
+ * A page gathering list, protected by per file i_mmap_lock. The
+ * lock is used to avoid list corruption from multiple unmapping
+ * of the same page since we are using page->lru.
+ */
LIST_HEAD(page_list);
WARN_ON(!is_vm_hugetlb_page(vma));