Index: usr.bin/top/commands.h
===================================================================
--- usr.bin/top/commands.h
+++ usr.bin/top/commands.h
@@ -33,6 +33,7 @@
 	CMD_renice,
 	CMD_idletog,
 	CMD_user,
+	CMD_excludeusers,
 	CMD_selftog,
 	CMD_thrtog,
 	CMD_viewtog,
Index: usr.bin/top/commands.c
===================================================================
--- usr.bin/top/commands.c
+++ usr.bin/top/commands.c
@@ -79,6 +79,7 @@
 	{'T', "toggle the displaying of thread IDs", false, CMD_toggletid},
 	{'t', "toggle the display of this process", false, CMD_selftog},
 	{'u', "display processes for only one user (+ selects all users)", false, CMD_user},
+	{'x', "toggle exclude/include user list from/to displaying", false, CMD_excludeusers},
 	{'w', "toggle the display of swap use for each process", false, CMD_swaptog},
 	{'z', "toggle the displaying of the system idle process", false, CMD_kidletog},
 	{' ', "update the display", false, CMD_update},
Index: usr.bin/top/machine.h
===================================================================
--- usr.bin/top/machine.h
+++ usr.bin/top/machine.h
@@ -18,6 +18,8 @@
 /* Log base 2 of 1024 is 10 (2^10 == 1024) */
 #define LOG1024		10
 
+extern int excludeusers;
+
 /*
  * the statics struct is filled in by machine_init
  */
Index: usr.bin/top/machine.c
===================================================================
--- usr.bin/top/machine.c
+++ usr.bin/top/machine.c
@@ -863,10 +863,14 @@
 			/* skip proc. that don't belong to the selected JID */
 			continue;
 
-		if (sel->uid[0] != -1 && !find_uid(pp->ki_ruid, sel->uid))
+		if (sel->uid[0] != -1 && !excludeusers && !find_uid(pp->ki_ruid, sel->uid))
 			/* skip proc. that don't belong to the selected UID */
 			continue;
 
+		if (sel->uid[0] != -1 && excludeusers && find_uid(pp->ki_ruid, sel->uid))
+			/* skip proc. that belong to the selected UID */
+			continue;
+
 		if (sel->pid != -1 && pp->ki_pid != sel->pid)
 			continue;
 
Index: usr.bin/top/top.1
===================================================================
--- usr.bin/top/top.1
+++ usr.bin/top/top.1
@@ -202,6 +202,11 @@
 .Ar username .
 This option currently only accepts usernames and will not understand
 uid numbers.
+.It Fl x
+When using
+.Fl U ,
+hide processes owned by
+.Ar username .
 .It Fl u
 Do not map uid numbers to usernames.
 Normally,
@@ -328,6 +333,10 @@
 and
 .Dq - ,
 respectively.
+.It x
+Toggle show/hide processess beloging to a specific set of usernames set by
+the command
+.Dq u .
 .It o
 Change the order in which the display is sorted.
 The sort key names include
Index: usr.bin/top/top.c
===================================================================
--- usr.bin/top/top.c
+++ usr.bin/top/top.c
@@ -55,6 +55,7 @@
 static int fmt_flags = 0;
 int show_args = false;
 int pcpu_stats = false;
+int excludeusers = false;
 
 /* signal handling routines */
 static sigret_t leave(int);
@@ -121,6 +122,7 @@
 {
     for (size_t i = 0; i < TOP_MAX_UIDS; ++i)
 	ps.uid[i] = -1;
+    excludeusers = false;
 }
 
 static int
@@ -313,7 +315,7 @@
 	    optind = 1;
 	}
 
-	while ((i = getopt_long(ac, __DECONST(char * const *, av), "CSIHPabijJ:nquvzs:d:U:m:o:p:Ttw", longopts, NULL)) != EOF)
+	while ((i = getopt_long(ac, __DECONST(char * const *, av), "CSIHPabijJ:nquvzxs:d:U:m:o:p:Ttw", longopts, NULL)) != EOF)
 	{
 	    switch(i)
 	    {
@@ -459,6 +461,10 @@
 		ps.swap = 1;
 		break;
 
+	      case 'x':
+		excludeusers = true;
+		break;
+
 	      case 'z':
 		ps.kidle = !ps.kidle;
 		break;
@@ -992,6 +998,18 @@
 				    no_command = true;
 				break;
 
+			    case CMD_excludeusers:
+				if (ps.uid[0] == -1) {
+				    new_message(MT_standout | MT_delayed,
+					"Empty user list. Use \"u\" to set the list");
+				} else {
+				    excludeusers = !excludeusers;
+				    new_message(MT_standout | MT_delayed, excludeusers ?
+					"Hiding users in user list" :
+					"Showing only users in user list");
+				}
+				break;
+
 			    case CMD_thrtog:
 				ps.thread = !ps.thread;
 				new_message(MT_standout | MT_delayed,