Index: sys/fs/tmpfs/tmpfs.h
===================================================================
--- sys/fs/tmpfs/tmpfs.h
+++ sys/fs/tmpfs/tmpfs.h
@@ -382,6 +382,8 @@
 	bool			tm_ronly;
 	/* Do not use namecache. */
 	bool			tm_nonc;
+	/* Do not update mtime. */
+	bool			tm_nomtime;
 };
 #define	TMPFS_LOCK(tm) mtx_lock(&(tm)->tm_allnode_lock)
 #define	TMPFS_UNLOCK(tm) mtx_unlock(&(tm)->tm_allnode_lock)
Index: sys/fs/tmpfs/tmpfs_vfsops.c
===================================================================
--- sys/fs/tmpfs/tmpfs_vfsops.c
+++ sys/fs/tmpfs/tmpfs_vfsops.c
@@ -113,6 +113,8 @@
 	struct vnode *vp, *mvp;
 	struct vm_object *obj;
 
+	if (VFS_TO_TMPFS(mp)->tm_nomtime)
+		return;
 	MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
 		if (vp->v_type != VREG) {
 			VI_UNLOCK(vp);
@@ -327,7 +329,7 @@
 	struct tmpfs_mount *tmp;
 	struct tmpfs_node *root;
 	int error;
-	bool nonc;
+	bool nomtime, nonc;
 	/* Size counters. */
 	u_quad_t pages;
 	off_t nodes_max, size_max, maxfilesize;
@@ -394,6 +396,7 @@
 	if (vfs_getopt_size(mp->mnt_optnew, "maxfilesize", &maxfilesize) != 0)
 		maxfilesize = 0;
 	nonc = vfs_getopt(mp->mnt_optnew, "nonc", NULL, NULL) == 0;
+	nomtime = vfs_getopt(mp->mnt_optnew, "nomtime", NULL, NULL) == 0;
 
 	/* Do not allow mounts if we do not have enough memory to preserve
 	 * the minimum reserved pages. */
@@ -440,6 +443,7 @@
 	new_unrhdr64(&tmp->tm_ino_unr, 2);
 	tmp->tm_ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
 	tmp->tm_nonc = nonc;
+	tmp->tm_nomtime = nomtime;
 
 	/* Allocate the root node. */
 	error = tmpfs_alloc_node(mp, tmp, VDIR, root_uid, root_gid,
Index: sys/vm/vm_object.h
===================================================================
--- sys/vm/vm_object.h
+++ sys/vm/vm_object.h
@@ -322,7 +322,8 @@
 vm_object_mightbedirty(vm_object_t object)
 {
 
-	return (object->type == OBJT_VNODE &&
+	return ((object->type == OBJT_VNODE || (object->type == OBJT_SWAP &&
+	    (object->flags & OBJ_TMPFS_NODE) != 0)) &&
 	    object->generation != object->cleangeneration);
 }
 
Index: sys/vm/vm_object.c
===================================================================
--- sys/vm/vm_object.c
+++ sys/vm/vm_object.c
@@ -1017,6 +1017,10 @@
  *	write out pages with PGA_NOSYNC set (originally comes from MAP_NOSYNC),
  *	leaving the object dirty.
  *
+ *	For swap objects backing tmpfs regular files, do not flush anything,
+ *	but remove write protection on the mapped pages to update mtime through
+ *	mmaped writes.
+ *
  *	When stuffing pages asynchronously, allow clustering.  XXX we need a
  *	synchronous clustering mode implementation.
  *
@@ -1038,8 +1042,7 @@
 
 	VM_OBJECT_ASSERT_WLOCKED(object);
 
-	if (object->type != OBJT_VNODE || !vm_object_mightbedirty(object) ||
-	    object->resident_page_count == 0)
+	if (!vm_object_mightbedirty(object) || object->resident_page_count == 0)
 		return (TRUE);
 
 	pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) != 0 ?
@@ -1149,7 +1152,13 @@
 	for (tp = p_first, i = 0; i < count; tp = TAILQ_NEXT(tp, listq), i++)
 		ma[i] = tp;
 
-	vm_pageout_flush(ma, count, pagerflags, mreq, &runlen, eio);
+	if (object->type == OBJT_VNODE) {
+		vm_pageout_flush(ma, count, pagerflags, mreq, &runlen, eio);
+	} else {
+		for (i = 0; i < count; i++)
+			vm_page_xunbusy(ma[i]);
+		runlen = count - mreq + 1;
+	}
 	return (runlen);
 }