diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index 9471225..ef757fc 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -375,6 +375,7 @@
 Swap:                  0 kB
 KernelPageSize:        4 kB
 MMUPageSize:           4 kB
+Locked:              374 kB
 
 The first of these lines shows the same information as is displayed for the
 mapping in /proc/PID/maps.  The remaining lines show the size of the mapping
@@ -670,6 +671,8 @@
 
 > cat /proc/meminfo
 
+The "Locked" indicates whether the mapping is locked in memory or not.
+
 
 MemTotal:     16344972 kB
 MemFree:      13634064 kB
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index c3755bd..60b9148 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -418,7 +418,8 @@
 		   "Anonymous:      %8lu kB\n"
 		   "Swap:           %8lu kB\n"
 		   "KernelPageSize: %8lu kB\n"
-		   "MMUPageSize:    %8lu kB\n",
+		   "MMUPageSize:    %8lu kB\n"
+		   "Locked:         %8lu kB\n",
 		   (vma->vm_end - vma->vm_start) >> 10,
 		   mss.resident >> 10,
 		   (unsigned long)(mss.pss >> (10 + PSS_SHIFT)),
@@ -430,7 +431,9 @@
 		   mss.anonymous >> 10,
 		   mss.swap >> 10,
 		   vma_kernel_pagesize(vma) >> 10,
-		   vma_mmu_pagesize(vma) >> 10);
+		   vma_mmu_pagesize(vma) >> 10,
+		   (vma->vm_flags & VM_LOCKED) ?
+			(unsigned long)(mss.pss >> (10 + PSS_SHIFT)) : 0);
 
 	if (m->count < m->size)  /* vma is copied successfully */
 		m->version = (vma != get_gate_vma(task)) ? vma->vm_start : 0;