Operation Manual
To change the niceness of a running process, use renice priority -p process
id, for example:
renice +5 3266
To renice all processes owned by a specic user, use the option -u user. Process
groups are reniced by the option -g process group id.
13.4 Memory
13.4.1 Memory Usage: free
The utility free examines RAM and swap usage. Details of both free and used mem-
ory and swap areas are shown:
tux@mercury:~> free
total used free shared buffers cached
Mem: 2062844 2047444 15400 0 129580 921936
-/+ buffers/cache: 995928 1066916
Swap: 2104472 0 2104472
The options -b, -k, -m, -g show the output in bytes, KB, MB, or GB, respectively.
The parameter -d delay ensures that the display is refreshed every delay seconds.
For example, free -d 1.5 produces an update every 1.5 seconds.
13.4.2 Detailed Memory Usage:
/proc/meminfo
Use /proc/meminfo to get more detailed information on memory usage than with
free. Actually free uses some of the data from this le. See an example output from
a 64bit system below. Note that it slightly differs on 32bit systems due to different
memory management):
tux@mercury:~> cat /proc/meminfo
MemTotal: 8182956 kB
MemFree: 1045744 kB
Buffers: 364364 kB
Cached: 5601388 kB
SwapCached: 1936 kB
System Monitoring Utilities 191