Top is designed for Linux. The free concept in the FreeBSD VM is quite different from the other OS, and using the top to view RAM memory is meaningless for FreeBSD. The correct way is to look at the Vmstat.
Procs memory page disk faults CPU
R B W swap free re mf mi po fr de SR f0 s0 S1 S2 in SY CS US sy ID
0 0 0 14888 19120 0 4 2 11 10 0 0 0 0 0 8 198 2158 98 11 19-69
The unit of swap should be k, not M. There are two more important parameters are pi, PO, indicating the memory of the transfer, pull out the page, Unit is k, but the value as a measure, I am not clear, do not know whether there is experience value.
Also, it is best to use the Vmstat t [n] command, such as Vmstat 5 5, to represent an n (5) Secondary sample in T (5) seconds. If you only use Vmstat to reflect the real system situation, try it and see the results.
Procs:
r--> number of processes waiting in the run queue
B--> the number of processes waiting for IO
W--> can enter a process that runs the queue but is replaced
Memoy
Swap--> currently available swap memory (k)
free--> free memory (k)
Pages
re--"Recycled pages
mf--"Not a serious error page
pi--"Number of pages entered (k)
po--the number of pages (k)
fr--Number of free pages (k)
de--the number of misses in the page read in advance
sr--pages scanned by the clock algorithm
Disk operation is displayed per second. s for SCSI disk, 0 for disk number
Fault shows the number of interrupts per second
in--"Equipment interrupted
sy--"System interrupted
cy--"CPU Switching
CPU indicates the CPU usage state
cs--the time used by the user process
sy--the time used by the system process
id--"CPU Idle Time
Explain:
If R is often greater than 4 and the ID is often less than 40, the CPU load is heavy.
If the Pi,po is not equal to 0 for a long time, it indicates insufficient memory.
If disk is often not equal to 0, and the queue in B is greater than 3, the IO performance is not good.