Index: usr.bin/vmstat/vmstat.8
===================================================================
--- usr.bin/vmstat/vmstat.8
+++ usr.bin/vmstat/vmstat.8
@@ -248,31 +248,33 @@
 displays the following information:
 .Bl -tag -width indent
 .It procs
-Information about the numbers of processes in various states.
+Information about the number of threads in various states:
 .Pp
 .Bl -tag -width indent -compact
 .It r
-in run queue
+running or in run queue
 .It b
 blocked for resources (i/o, paging, etc.)
 .It w
-runnable or short sleeper (< 20 secs) but swapped
+swapped out
 .El
 .It memory
 Information about the usage of virtual and real memory.
-Virtual pages (reported in units of 1024 bytes) are considered active if
-they belong to processes which are running or have run in the last 20
-seconds.
+Active virtual memory is a sum of all of the virtual pages belonging
+to active virtual memory objects.
+Active virtual memory objects are mapped in at least one process.
+Note that the entire memory object's size is considered active even if
+only a subset of the object's pages are currently mapped.
 .Pp
 .Bl -tag -width indent -compact
 .It avm
-active virtual pages
+active virtual memory
 .It fre
 size of the free list
 .El
 .It page
 Information about page faults and paging activity.
-These are averaged each five seconds, and given in units per second.
+These are given in units per second.
 .Pp
 .Bl -tag -width indent -compact
 .It flt
@@ -290,7 +292,7 @@
 .\" .It de
 .\" anticipated short term memory shortfall
 .It sr
-pages scanned by clock algorithm, per-second
+pages scanned by clock algorithm
 .El
 .It disks
 Disk operations per second (this field is system dependent).
@@ -319,15 +321,15 @@
 will only display the given devices or the devices matching the pattern,
 and will not randomly select other devices in the system.
 .It faults
-Trap/interrupt rate averages per second over last 5 seconds.
+Trap/interrupt rates per second.
 .Pp
 .Bl -tag -width indent -compact
 .It in
-device interrupts per interval (including clock interrupts)
+device interrupts (including clock interrupts)
 .It sy
-system calls per interval
+system calls
 .It cs
-cpu context switch rate (switches/interval)
+cpu context switches
 .El
 .It cpu
 Breakdown of percentage usage of CPU time.
@@ -336,7 +338,7 @@
 .It us
 user time for normal and low priority processes
 .It sy
-system time
+system and interrupt time
 .It id
 cpu idle
 .El
@@ -352,10 +354,7 @@
 The command:
 .Dl vmstat -w 5
 will print what the system is doing every five
-seconds; this is a good choice of printing interval since this is how often
-some of the statistics are sampled in the system.
-Others vary every second and running the output for a while will make it
-apparent which are recomputed every second.
+seconds.
 .Pp
 The command:
 .Dl vmstat -p da -p cd -w 1