max_thread_proc(5)                                       max_thread_proc(5)
                          Tunable Kernel Parameters



 NAME    [Toc]    [Back]
      max_thread_proc - defines the maximum number of concurrent threads
      allowed per process.

 VALUES    [Toc]    [Back]
    Failsafe
      256

    Default    [Toc]    [Back]
      256

    Allowed values    [Toc]    [Back]
      Between 64 and nkthread

    Recommended values    [Toc]    [Back]
      256

 DESCRIPTION    [Toc]    [Back]
      max_thread_proc is a dynamic tunable that limits the maximum number of
      threads allowed per process on the system.  When tuning
      max_thread_proc, the maximum number of threads allowed per process
      will be the new value of max_thread_proc.  No process will be able to
      create new threads such that the total count of its threads exceeds
      max_thread_proc.

    Who is Expected to Change This Tunable?
      System administrators that run applications on their systems requiring
      a high number of threads per process.

    Restrictions on Changing    [Toc]    [Back]
      The effect of tuning max_thread_proc on existing processes is
      undefined.  However, existing threads will not be effected.

    When Should the Value of This Tunable Be Raised?
      The value of max_thread_proc should be raised if there is a need to
      run an application that requires a higher number of threads per
      process than what max_thread_proc is currently set to accommodate.
      Also, if thread creation fails with the errno value of EAGAIN, then it
      could indicate that the max_thread_proc has been reached.  However,
      reaching max_thread_proc is not the only reason why a thread creation
      could fail with EAGAIN.  EAGAIN may be returned if the nkthread system
      tunable has been reached or memory on the system is exhausted.

    What Are the Side Effects of Raising the Value?
      A group of processes may be able to exhaust the system wide limit of
      threads on the system.

    When Should the Value of This Tunable Be Lowered?
      If you feel that it is necessary to limit the number of threads
      allowed per process.




 Hewlett-Packard Company            - 1 -      HP-UX 11i Version 2: Sep 2004






 max_thread_proc(5)                                       max_thread_proc(5)
                          Tunable Kernel Parameters



    What Are the Side Effects of Lowering the Value?
      Some applications which need a high number of threads may behave
      differently or fail to operate.

    What Other Tunable Values Should Be Changed at the Same Time?
      You may want to look at the value of nkthread.

 WARNINGS    [Toc]    [Back]
      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.

      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 tunable
      values, consult the documentation for the kernel software being
      installed. For information about optional kernel software that was
      factory installed on your system, see HP-UX Release Notes at
      http://docs.hp.com.

 AUTHOR    [Toc]    [Back]
      max_thread_proc was developed by HP.

 SEE ALSO    [Toc]    [Back]
      nkthread(5).


 Hewlett-Packard Company            - 2 -      HP-UX 11i Version 2: Sep 2004