The value of tmnxBsxIsaAaGrpFromSubWaSBfHiWmk specifies the
high watermark for the weighted average utilization of the shared
buffer space in the 'FromSub' buffer pool for each ISA. When
a buffer pool is not in the overload state and the wa-shared
buffer utilization for an ISA is greater than or equal to
tmnxBsxIsaAaGrpFromSubWaSBfHiWmk the ISA 'FromSub' buffer pool
enters an overload state and an overload notification
tmnxBsxIsaAaGrpFmSbWaSBufOvld is raised.
The value must be greater than tmnxBsxIsaAaGrpFromSubWaSBfLoWmk.
The value of -1 represents the maximum wa-shared buffer
utilization indicating this high watermark will not be met.