Are Linux Time Command Results Affected by System Boot?

Question

I use Linux time and GNU shell commands for basic benchmarking.

But my system sometimes has a different load from other users.

Are the "user" and "sys" outputs affected by these other users?

I would think that for a program with clean processing, the results should not be affected, since the OS (I think), able to accurately track the fraction of the process time.

I'm not sure what the results will be for heavy I / O processes.

Can someone explain this relationship? Quotes are always welcome.

Answer 1

The time command does not report context switching costs because this is not a system call. Thus, you will not see changes in the output of the system time due to context switches. If there is resource competition due to IO / CPU requests from other users, this will affect the lock time and completion time, so the sys and user times can be very high.