diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index 9036dbf16156fa4a26b3ecd4b9d15e52e3af931b..4cddbce85ac9ad175743f5f4384a32937bf87888 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -413,6 +413,7 @@ Private_Clean:         0 kB
 Private_Dirty:         0 kB
 Referenced:          892 kB
 Anonymous:             0 kB
+LazyFree:              0 kB
 AnonHugePages:         0 kB
 ShmemPmdMapped:        0 kB
 Shared_Hugetlb:        0 kB
@@ -442,6 +443,11 @@ accessed.
 "Anonymous" shows the amount of memory that does not belong to any file.  Even
 a mapping associated with a file may contain anonymous pages: when MAP_PRIVATE
 and a page is modified, the file page is replaced by a private anonymous copy.
+"LazyFree" shows the amount of memory which is marked by madvise(MADV_FREE).
+The memory isn't freed immediately with madvise(). It's freed in memory
+pressure if the memory is clean. Please note that the printed value might
+be lower than the real value due to optimizations used in the current
+implementation. If this is not desirable please file a bug report.
 "AnonHugePages" shows the ammount of memory backed by transparent hugepage.
 "ShmemPmdMapped" shows the ammount of shared (shmem/tmpfs) memory backed by
 huge pages.
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 312578089544dbd652aac303d0cbabee8fbcb968..f0c8b33d99b137e0c607448237216c2826df3fe8 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -441,6 +441,7 @@ struct mem_size_stats {
 	unsigned long private_dirty;
 	unsigned long referenced;
 	unsigned long anonymous;
+	unsigned long lazyfree;
 	unsigned long anonymous_thp;
 	unsigned long shmem_thp;
 	unsigned long swap;
@@ -457,8 +458,11 @@ static void smaps_account(struct mem_size_stats *mss, struct page *page,
 	int i, nr = compound ? 1 << compound_order(page) : 1;
 	unsigned long size = nr * PAGE_SIZE;
 
-	if (PageAnon(page))
+	if (PageAnon(page)) {
 		mss->anonymous += size;
+		if (!PageSwapBacked(page) && !dirty && !PageDirty(page))
+			mss->lazyfree += size;
+	}
 
 	mss->resident += size;
 	/* Accumulate the size in pages that have been accessed. */
@@ -771,6 +775,7 @@ static int show_smap(struct seq_file *m, void *v, int is_pid)
 		   "Private_Dirty:  %8lu kB\n"
 		   "Referenced:     %8lu kB\n"
 		   "Anonymous:      %8lu kB\n"
+		   "LazyFree:       %8lu kB\n"
 		   "AnonHugePages:  %8lu kB\n"
 		   "ShmemPmdMapped: %8lu kB\n"
 		   "Shared_Hugetlb: %8lu kB\n"
@@ -789,6 +794,7 @@ static int show_smap(struct seq_file *m, void *v, int is_pid)
 		   mss.private_dirty >> 10,
 		   mss.referenced >> 10,
 		   mss.anonymous >> 10,
+		   mss.lazyfree >> 10,
 		   mss.anonymous_thp >> 10,
 		   mss.shmem_thp >> 10,
 		   mss.shared_hugetlb >> 10,