QIO Configuration and Management Manual

Configuring the QIO Subsystem
QIO Configuration and Management Manual—424717-008
2-15
Setting the Size of QIO Memory
Some applications define their own flat segments. You might want to decrease the
segment size such that the end of the QIO segment remains at 0x42000000-1. By
sizing the QIO segment to end in the default setting, you can ensure that the
environment will not encroach on flat segments that follow the QIO segment.
Remember that an additional 32 MB of space for the IOperm segment is created right
after the main QIO segment. To allocate only 128 MB for the QIO memory segment,
specify the following attribute in the configuration file:
SegmentSize 128M
Sometimes you may want to change both the segment size and the base address.
Following is an example of an allocation that increases the amount of memory that the
process heap can allocate while not interfering with other flat segment allocations:
SegmentSize 128M
BaseAddress 0x38000000
In this example, the starting address of the shared segment is 0x38000000 and the
starting address of the IOperm segment is 0x40000000. The next available address for
client processes is 0x42000000.
Figure 2-5. QIO Shared Memory Segment Reduced From the Default of 512 MB
2000.0000
0800.0000
8000.0000
QIO Shared Memory
Segment
QIO IOperm 32 MB
(No change in size)
Flat Segment Memory
Space Reserved for
Programs
Base Addresses
4200.0000
(QIO default)
VST012.vsd
QIO shared memory space
reduced by a smaller
specified segment size
Process Heap and
Process Globals
Unassigned Flat Memory
Space