[PATCH] __unmap_hugepage_range(): add comment

[powerpc.git] / mm / hugetlb.c

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index a088f59..f7355bf 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -365,6 +365,11 @@ void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
        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));