-One time setup (pick appropriate one for your CPU):
-P3 opcontrol --setup --vmlinux=/boot/vmlinux \
- --ctr0-event=CPU_CLK_UNHALTED --ctr0-count=100000
-Athlon/x86-64 opcontrol --setup --vmlinux=/boot/vmlinux \
- --ctr0-event=RETIRED_INSNS --ctr0-count=100000
-P4 opcontrol --setup --vmlinux=/boot/vmlinux \
- --ctr0-event=GLOBAL_POWER_EVENTS \
- --ctr0-unit-mask=1 --ctr0-count=100000
+For superior results, be sure to enable the local APIC. If opreport sees
+a 0Hz CPU, APIC was not on. Be aware that idle=poll may mean a performance
+penalty.
+
+One time setup:
+ opcontrol --setup --vmlinux=/boot/vmlinux