beostat_count_idle_cpus -- count number of idle CPUS in cluster
- The value of CPU usage below which the CPU will be considered idle.
beostat_count_idle_cpus executes on the master node and counts the
number of CPUs in the entire cluster that are available to the current
user/group and have CPU usage below a given threshold. Note that an easy
way to count the total number of CPUs available to a user independent of
the usage is to use an arbitrarily large threshold value.
int max, fif; max = beostat_count_idle_cpus (9999.0); fif = beostat_count_idle_cpus (0.5); printf ("%d of the %d CPUs available are busy.\n", (max-fif), max);
Returns the number of CPUs that are both available for the caller and have usage below the threshold. If an error occurs, it will return -1.
This function relies on the
Beostat subsystem, which consists of the
proc filesystem on the remote node, the
sendstats daemon on the
remote node, the
recvstats daemon on the master node, and two shared
memory files in the directory
/var/shm. If any part of the system
breaks down, this function could fail.