These functions are used to retrieve resource usage information:
who) |
The fields of the return value each describe how a particular system resource has been used, e.g. amount of time spent running is user mode or number of times the process was swapped out of main memory. Some values are dependent on the clock tick internal, e.g. the amount of memory the process is using.
For backward compatibility, the return value is also accessible as a tuple of 16 elements.
The fields ru_utime and ru_stime of the return value are floating point values representing the amount of time spent executing in user mode and the amount of time spent executing in system mode, respectively. The remaining values are integers. Consult the getrusage(2) man page for detailed information about these values. A brief summary is presented here:
Index | Field | Resource |
---|---|---|
0 |
ru_utime | time in user mode (float) |
1 |
ru_stime | time in system mode (float) |
2 |
ru_maxrss | maximum resident set size |
3 |
ru_ixrss | shared memory size |
4 |
ru_idrss | unshared memory size |
5 |
ru_isrss | unshared stack size |
6 |
ru_minflt | page faults not requiring I/O |
7 |
ru_majflt | page faults requiring I/O |
8 |
ru_nswap | number of swap outs |
9 |
ru_inblock | block input operations |
10 |
ru_oublock | block output operations |
11 |
ru_msgsnd | messages sent |
12 |
ru_msgrcv | messages received |
13 |
ru_nsignals | signals received |
14 |
ru_nvcsw | voluntary context switches |
15 |
ru_nivcsw | involuntary context switches |
This function will raise a ValueError if an invalid who parameter is specified. It may also raise error exception in unusual circumstances.
Changed in version 2.3: Added access to values as attributes of the returned object.
) |
The following RUSAGE_* symbols are passed to the getrusage() function to specify which processes information should be provided for.