HP PRM Version C.03.06 release notes - (March 2012)

The CPU scheduler that PRM uses schedules processes by:
• Distributing all the processes from each PRM group in round-robin fashion
starting from the same CPU every time (with the CPUs being cores or logical
CPUs depending on whether Hyper-Threading is enabled)
• Once all the processes are distributed, CPUs with spare cycles inherit
processes from CPUs that are completely busy
Because the round-robin distribution always starts with the same CPU, that
CPU—and other CPUs at the start of the distribution—can quickly become loaded
with processes. For example, assume there are many groups with just one or two
processes. Also assume a single PRM group has enough processes to distribute
at least one process per CPU and that each of those processes consumes all of
its CPU’s cycles.
As a result, there are no CPUs with spare cycles to inherit processes. With all
those processes crowded on the first CPUs in the round-robin distribution, the
processes’ associated PRM groups may not be able to get their CPU entitlements.
Workaround On HP-UX 11i v1 (B.11.11), install patches PHKL_30034, PHKL_30035,
PHKL_31993, PHKL_31995, and PHKL_32061. Install all these patches at the
same time. These patches address CR# JAGae14311.
On HP-UX 11i v2 (B.11.23), install the BUNDLE11i patch bundle. Any version
of this bundle is acceptable.
Unable to achieve CPU entitlement due to number of processes
Issue PRM provides a PRM group its entitlement on an SMP system with Hyper-Threading
disabled by granting the group its entitlement on each core. If the group does
not have at least one process for each core, PRM compensates by proportionally
increasing the PRM group’s entitlements on cores where it does have processes.
For example, for a PRM group with a single-threaded process, a 10% entitlement
of four cores results in a 40% entitlement on one core.
Assume this same PRM group were allocated 50% of the four cores. PRM would
give the group an entitlement of 100% on two cores. However, because the
group has only the one thread, it can use only one core, resulting in a 25%
entitlement.
Workaround There is no workaround. However, be aware of how your applications run so
that you do not give them resource entitlements they cannot use.
Secure Resource Partitions: Blocked port on a virtual network interface
Issue Using the optional HP-UX feature Security Containment, you can set up a virtual
network interface for each secure compartment. A process in one secure
compartment can bind to a socket on a virtual network interface associated with
a different secure compartment. Although this process will not be able to accept
connections or use the socket to send or receive data, it does prevent other
processes from binding to that socket.
Workaround Be sure your applications that access the network bind only to sockets on the
virtual network interface created for their respective secure compartments.
For more information, see the Security Containment release notes and the HP-UX
11i Security Containment Administrator’s Guide.
Unable to achieve CPU entitlement due to number of processes 17