CPU time

[Stalin]

Could someone explain what does 'cpu time' mean? For example, there is an option in /etc/security/limits.conf where you can set maximum cpu time per process, but I am not sure what is this supposed to mean.

[puntmuts]

CPU time is the time a process/program actually uses the CPU. CPU is divided between the processes/programs, since you have more processes/programs active then there are CPU's in your system

See 'top' for some information about how much CPU Time is used by processes/programs .

[scientica]

one way it to say "for how many percent of N seconds did the CPU do somethign usefull" (usefull = not in the kernels passing time code ) [cw]ould be "the CPU usage during the past N seconds is X percent".
I think those limits is one way to make you say to the system, this application may only use this much CPU time and then wait for a little while so other processes can do something. I can imagine uses for making sure eg root always can do something, even if some process has gone rennagade and just steal CPU time.