MAXTHREADS
MAXTHREADS is the maximum number of threads that a single process can have active concurrently. If an application needs to create more than the recommended maximum in SAMPLIB, it must minimize storage allocated below the 16 M line by specifying C run-time options. For more information, see set_thread_limits (BPX1STL, BPX4STL) — Change task or thread limits for pthread_created threads in z/OS® UNIX System Services Programming: Assembler Callable Services Reference.
You can set a system-wide limit in BPXPRMxx and then set higher
limits for individual users by using the RACF® ADDUSER or ALTUSER command to specify the
THREADSMAX limit on a per user basis as follows:
ALTUSER userid OMVS(THREADSMAX(nnnn))