Personal tools
You are here: Home UiT files-uit Performance tools the time command

the time command

by Peter Wind last modified Oct 21, 2011 10:37 AM

time spent, memory and page faults

Gives overall user, system and elapsed time for a program or command

Note that the command

/usr/bin/time MyCommand

and the command

time MyCommand

are different (!). The last one is a shell command.

/usr/bin/time can give information about max memory used, page faults and swapped memory. NB: Not all fields are available on all systems.

Minor page faults give a relatively modest performance penalty (typically 30 cycles). In case of a major page fault the page has to be read in from  disk; this is very costly and is a sign that the code has too little memory available.

 

Document Actions