hugetlb: use mmu_gather instead of a temporary linked list for accumulating pages

Use a mmu_gather instead of a temporary linked list for accumulating pages
when we unmap a hugepage range

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 2 deletions

diff --git a/mm/memory.c b/mm/memory.c
index 91f69459d3e8..59e5bebc2e35 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1343,8 +1343,11 @@ static void unmap_single_vma(struct mmu_gather *tlb,
                          * Since no pte has actually been setup, it is
                          * safe to do nothing in this case.
                          */
-                        if (vma->vm_file)
-                                unmap_hugepage_range(vma, start, end, NULL);
+                        if (vma->vm_file) {
+                                mutex_lock(&vma->vm_file->f_mapping->i_mmap_mutex);
+                                __unmap_hugepage_range(tlb, vma, start, end, NULL);
+                                mutex_unlock(&vma->vm_file->f_mapping->i_mmap_mutex);
+                        }
                 } else
                         unmap_page_range(tlb, vma, start, end, details);
         }