FreeBSD NOTES
Priorities are shown the same as they exist in process data structures, ranging from 0 to 255. Note that this is not the same as the ps(1) “pri” column, which subtracts 84 from each number before displaying it. Priority numbers fall in to priority classes as follows:

0 - 63
    Interrupt threads

64 - 127
    Top half kernel threads

128 - 159
    Realtime user threads

160 - 223
    Time sharing user threads

224 - 255
    Idle user threads

FreeBSD THREADS
Starting with FreeBSD 8.0 the display of individual threads can be toggled with the synonymous commands t and H. Information about state, flags, CPU time and percent cpu are shown for each individual thread. Other information is identical for all threads in the same process.

FreeBSD ALTERNATE DISPLAY
FreeBSD supports an alternate process display which shows i/o information. Since this information is tracked per process and not per thread, the per-thread display is not supported in this mode. All fields calculate the number of operations observed since the last update and are displayed as a per-second rate. The fields in this display are as follows:

VCSW
    Voluntary context switches

IVCSW
    Involuntary context switches

READ
    Number of blocks read

WRITE
    Number of blocks written

FAULT
    Number of page faults

TOTAL
    Total number of i/o operations

PERCENT
    Percentage of total i/o attributed to this process. If no i/o occured then this field is 0 for all processes.

FreeBSD KERNEL SUMMARY
All rates are shown per-second.

Ctx Number of context switches.

Trap
    Number of kernel traps.

Intr
    Number of device interrupts.

Soft
    Number of software interrupts.

Fork
    Number of forks, vforks, and rforks.

Flt Total number of page faults.

Pgin
    Number of pages paged or swapped in to physical memory.

Pgout
    Number of pages paged or swapped out from physical memory.

Fr  Total number of pages freed.

FreeBSD MEMORY SUMMARY
Memory: 10M Act 1208K Inact 3220K Wired 132K Free 25% Swap, 2924Kin 2604Kout

K:  Kilobyte

M:  Megabyte

G:  Gigabyte

%:  1/100

Act:
    number of pages active

Inact:
    number of pages inactive

Wired:
    number of pages wired down

Free:
    number of pages free

Swap:
    swap usage

Kin:
    kilobytes swap pager pages paged in (last interval)

Kout:
    kilobytes swap pager pages paged out (last interval)

See /usr/include/sys/vmmeter.h and /sys/vm/vm_meter.c.

Contributors: Christos Zoulas, Steven Wallace, Wolfram Schneider, Monte Mitzelfelt.

This module was retrofitted from FreeBSD 4.6.2 sources.