hpux man page for nproc

nproc(5)							File Formats Manual							  nproc(5)

NAME
       nproc - limits the number of processes allowed to exist simultaneously

VALUES
   Failsafe
   Default
   Allowed values
       The  system  may  allow settings higher than 60,000 but such values are unsupported.  Setting below interferes with the system's ability to
       execute in multi-user mode.  Some configurations may have a higher minimum.

       must be greater than

       must be greater than

   Recommended values
       processes per processor.

DESCRIPTION
       The tunable controls the absolute number of processes allowed on a system at any given time.  Increasing it allows more processes, and low-
       ering it restricts the number of processes.

       You  can  determine that is too low when the message is seen in the message buffer.  Use or to read the message buffer.	This message indi-
       cates that an application was unable to create a new process.  Setting too low can cause application failures due to an inability  to  fork
       new processes.

       You  can determine how many processes have been used simultaneously by calling and examining the This field indicates the "high water" mark
       of the number of processes that have been simultaneously used.

   Who Is Expected to Change This Tunable?
       Anyone expecting to run large numbers of processes.

   Restrictions on Changing
       None.  This tunable is dynamic.

   When Should the Value of This Tunable Be Raised?
       Increase the value of when running large numbers of processes simultaneously.

   What are the Side Effects of Raising the Value?
       None.

   When Should the Value of This Tunable Be Lowered?
       Lower the value only to limit the number of processes on the system, or when there is memory pressure and the value of  is  far	above  the
       expected usage.

   What are the Side Effects of Lowering the Value?
       Lowering the value increases the risk of application failure due to the inability to fork new processes.

   What Other Tunable Values Should Be Changed at the Same Time?
       Increase to ensure there are sufficient threads for each process.

       Adjust as the default formula is multiple of

       A single user may not consume all processes on the system (see

       Some of these other tunables used to adjust automatically.  These adjustments must now be made explicitly.

       Other tunables may require a reboot to take effect.  So, dramatic increases in the value of without reboot should be made with caution.

WARNINGS
       All  HP-UX kernel tunable parameters are release specific.  This parameter may be removed or have its meaning changed in future releases of
       HP-UX.

       The effective number of processes allowed to exist simultaneously may be affected by the values of the tunables and

       Some applications may have been coded with a built-in assumption that the number of processes cannot exceed 30,000, which was  the  maximum
       imposed by prior versions of HP-UX.  Such applications may fail on configurations which allow and/or create more than 30,000 processes.

       The HP-UX kernel creates internal data structures optimized for the value of the tunable parameter at boot time.  After significant changes
       to the tunable it is recommended that a reboot be scheduled so that the kernel can reoptimize these internal data structures.

       Installation of optional kernel software, from HP or other vendors, may cause changes to tunable  parameter  values.   After  installation,
       some  tunable  parameters may no longer be at the default or recommended values.  For information about the effects of installation on tun-
       able values, consult the documentation for the kernel software being installed.	For information about optional kernel  software  that  was
       factory installed on your system, see at

AUTHOR
       was developed by HP.

SEE ALSO
       ksi_alloc_max(5), maxuprc(5), nkthread(5), process_id_max(5), process_id_min(5).

       whitepaper, available on

							     Tunable Kernel Parameters							  nproc(5)