shared memory control

[Jerome Draper <jdraper@xxxxxxxxxxxxx>]

I am installing Websphere MQ for iSeries v5.3 and Chap 2-Installing and 
migrating to WebSphere MQ for iSerie talks about setting 5 system values but 
give NO information about the fifth one - QSHRMEMCTL.

Does anyone have information about the implication of this system value?

 :                                                                            : 
 :  QSHRMEMCTL                                                                : 
 :                                                                            : 
 :      Shared memory control.  Controls whether or not users are allowed to  : 
 :      use shared memory or mapped memory that has write capability.         : 
 :                                                                            : 
 :      NOTE: You must have *ALLOBJ and *SECADM special authorities to        : 
 :      change this system value.                                             : 
 :                                                                            : 
 :      A change to this system value takes effect immediately.  The shipped  : 
 :      value is 1.                                                           : 
 :                                                                            : 
 :  Shared memory control                                                     : 
 :                                                                            : 
 :      0           Users cannot use shared memory, or use mapped memory      : 
 :                  that has write capability.                                : 
 :                                                                            : 
 :                  This value means that users cannot use shared-memory      : 
 :                  APIs (For example, shmat() - Shared Memory Attach API),   : 
 :                  and cannot use mapped memory objects that have write      : 
 :                  capability (For example, mmap() - Memory Map a File API   : 
 :                  provides this function).                                  : 
 :                                                                            : 
 :                  Use this value in environments with higher security       : 
 :                  requirements.                                             : 
 :                                                                            : 
 :      1           Users can use shared memory or mapped memory that has     : 
 :                  write capability.                                         : 
 :                                                                            : 
 :                  This value means that users can use shared-memory APIs    : 
 :                  (For example, shmat() - Shared Memory Attach API), and    : 
 :                  can use mapped memory objects that have write capability  : 
 :                  (For example, mmap() - Memory Map a File API provides     : 
 :                  this function).                                           : 
 :                                                                            : 
 :                  Use this value in environments where pointers may be      : 
 :                  shared among programs between different jobs.             : 


Jerome Draper, Trilobyte Software Systems