The value of tmnxBsxIsaAaGrpToSubWaSBfHiWmk specifies the
high watermark for the weighed average utilization of the shared
buffer space in the 'ToSub' 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
tmnxBsxIsaAaGrpToSubWaSBfHiWmk the ISA 'ToSub' buffer pool enters
an overload state and an overload notification
tmnxBsxIsaAaGrpToSbWaSBufOvld is raised.
The value must be greater than tmnxBsxIsaAaGrpToSubWaSBfLoWmk.
The value of -1 represents the maximum wa-shared buffer
utilization indicating this high watermark will not be met.