User guide

Intel’s Core 2 processors have 5 performance counters per core. Two of these are fully programmable, and can

count 116 (#1) or 115 (#2) different types of events. The other three counters are fixed, and can only count one

type of event (for counter 3: INSTR_RETIRED.ANY, 4: CPU_CLK_UNHALTED.CORE, and 5:

CPU_CLK_UNHALTED.REF).

In addition, the available events can be modified by enabling any of the eight Event-Mask bits associated with

each programmable counter. The event-mask bits are critical to determining exactly which events will be

counted. Most of the events can be selected without enabling any event-mask bits at all. The mask bits just

modify the type of event slightly or the way the counter gets incremented when the event occurs. In particular,

the mask settings often act as an event filter, limiting or expanding the selection of related events that can be

counted simultaneously. In contrast, for some types of events youmust set event-mask bits properly, in order

to count anything at all. These bits are labeled ‘Required’ in the event-mask bit list.

The table below lists each Event Name, the counter (PMC) number(s) for counters which can count the event,

the event’s number, and the valid mask bits that can be enabled, for every useful event type. This last column

lists mask bits using numbers between 0 and 7. Missing numbers indicate bits that are reserved and should

not be enabled. If no mask bits are valid for that type of event, then “none” is listed.

In Shark, more complete documentation as to what the event names mean and how each mask bit modifies

the count are provided as “tool-tips” when you hover the mouse over an event name in the popup menu, or

over a specific bit name in the event-mask list. The event-mask bit controls are only accessible from the Advanced

View controls shown in the Timed Counters: The Performance Counter Spreadsheet (page 111).

For more information on how to configure these counters, see Intel CPU Performance Counter

Configuration (page 209).

Valid Event-Mask BitsPMC NumberEvent NumberPerformance Counter Event Name

none1230BACLEARS

none1138BR_BAC_MISSP_EXEC

none1228BR_BOGUS

252

Intel Core 2 Performance Counter Event List