Simple tool for using a (configurable) nice level for all processes.
This thorn tries to renice all processes of Cactus to a given nice level.
To renice a process means to change its nice level after the start. The nice level is a way to control the
priority of processes for cpu power. It is always a good idea to give cpu-intensive jobs (like Cactus
runs) a low priority if you are using desktop machines, especially if other people are using them
too.
The nice level has a range of
to .
A higher number means less priority. Mostly, normal processes will get
and only the superuser (root) can use negative values. Also only root can lower the nice
level of a process, so if you nice your Cactus Run to 19, you cannot renice it later to an
lower nice-level. The nice level of single processes can be controled by the system commands
and/or
. In the
case of Cactus and Lamd this is not possible at startup. Therefore this thorn will set the nice level of your
processes at CCTK_PARAMCHECK (in the beginning of the calculation).
This thorn has only one parameter:
CCTK_INT Nice_nice
which is by default 19.
Note to developers:
This thorn uses and
and therefore needs the includes
sys/time.h,
errno.h
and sys/resource.h.
If these are not provided on some platform, please tell me.
nice_nice | Scope: private | INT |
Description: Nice level
| ||
Range | Default: 19 | |
-20:19 | The range for the nice is from -20 to 19, but only root can use negative values, default is
19.
| |
Implements:
nice
This section lists all the variables which are assigned storage by thorn CactusUtils/Nice. Storage can either last for the duration of the run (Always means that if this thorn is activated storage will be assigned, Conditional means that if this thorn is activated storage will be assigned for the duration of the run if some condition is met), or can be turned on for the duration of a schedule function.
NONE
CCTK_STARTUP
nice_renice
renice the process
Language: | c | |
Type: | function | |