HP-UX 11i Release Notes (December 2000)
HP-UX 11i Operating Environments
HP-UX 11i Operating Environment (new)
Chapter 480
MPC_GETNUMSPUS
returns the number of activated processors, whereas
previously, the function did not check whether the
processor is deactivated before incrementing the count.
MPC_GETFIRSTSPU
returns the first activated processor.
MPC_GETNEXTSPU
returns the next activated processor and will skip
deactivated ones.
MPC_GETNUMSPUS, MPC_GETFIRSTSPU & MPC_GETNEXTSPU
takes into account deactivated processors.
MPC_GETNUMSPUS
does not count deactivated processors and the other
two options will not return deactivated processors’
indices.
This is in line with the current specification of pstat and mpctl.
Prior to HP-UX 11i, the following commands incorrectly used the fields
in pstat and mpctl: top, sar, uptime, iostat, and vmstat. These
commands are fixed in HP-UX 11i in order to work correctly on iCOD
systems. These changes are only relevant to iCOD systems and systems
running the LPMC monitor in OnlineDiag; they do not affect other
systems.
Performance Issues This feature improves performance by allowing
additional parallel processing capacity for applications when iCOD
activations occur. It has a temporary side effect of allowing additional I/O
interrupt handling capacity via the deactivated processors. This aspect
changes once I/O revectoring is implemented.
Compatibility Issues Applications that are aware of the number of
processors in the system may need to be modified to work properly on an
iCOD system. Applications that are dependent on the number of active
processors most likely are dependent on the system calls mpctl and
pstat.
System measurement software may or may not be impacted by iCOD
because of these process management changes. Written properly, the