Modify interrupt load balancing policy on reboot/stop

When rebooting:
1. Stop irqbalance
2. Modify /proc/irq/*/smp_affinity so that McKernel cores are not
   included
3. Start irqbalance with McKernel cores and IHK IRQ banned from
   load balancing

When stopping:
1. Stop irqbalance
2. Restore /proc/irq/*/smp_affinity
3. Restart irqbalance with the system default settings

refs #760

arch/x86/tools/irqbalance_mck.in.in

@@ -0,0 +1,28 @@
+# irqbalance is a daemon process that distributes interrupts across
+# CPUS on SMP systems. The default is to rebalance once every 10
+# seconds. This is the environment file that is specified to systemd via the
+# EnvironmentFile key in the service unit file (or via whatever method the init
+# system you're using has.
+#
+# ONESHOT=yes
+# after starting, wait for a minute, then look at the interrupt
+# load and balance it once; after balancing exit and do not change
+# it again.
+#IRQBALANCE_ONESHOT=
+
+#
+# IRQBALANCE_BANNED_CPUS
+# 64 bit bitmask which allows you to indicate which cpu's should
+# be skipped when reblancing irqs. Cpu numbers which have their
+# corresponding bits set to one in this mask will not have any
+# irq's assigned to them on rebalance
+#
+IRQBALANCE_BANNED_CPUS=%mask%
+
+#
+# IRQBALANCE_ARGS
+# append any args here to the irqbalance daemon as documented in the man page
+#
+IRQBALANCE_ARGS=--banirq=%banirq%
+
+