HP-UX 11i June 2001 Release Notes

Process, Threads, Memory, and Kernel Parameters
Memory Windows
Chapter 8 169
failure as a compatibility failure as only the application owner or
software provider can certify how and if an application can run under
memory windows.
Errors due to incorrect usage may be subtle and normally not associated
with memory windows. In many cases software providers may have
already certified their applications with memory windows. Contact HP to
see if this is the case.
Configuration
By default, HP-UX ships with memory windows disabled.
To enable memory windows, set the kernel tunable parameter
max_mem_window to the desired amount. Customers can change this
value by placing the desired value in their kernel configuration file. The
system must be rebooted for the new value to take effect.
max_mem_window represents the number of memory windows beyond the
global default window.
• Setting max_mem_window to one creates a single memory window to
accompany the existing global memory window, or a total of two
memory windows one default and one user-defined.
• Setting max_mem_window to two produces a total of three memory
windows the default and two user-defined.
• Setting max_mem_window to 0 leaves only one memory window, the
default or global memory window.
What should the value be? That depends on the application
requirements and the applications installed on the system. HP
recommends that each ISV/application should document how many
windows it intends to use.
Use of memory windows does not affect the performance of processes.
There is no size requirement associated with memory windows. Any
machine running HP-UX (32-bit or 64-bit) and any hardware supporting
HP-UX release 11i can use memory windows.