◦Wrong Path

Percentage of Indirect branches for which the target path (taken/not-taken) was predicted incorrectly.

◦Wrong Target

Percentage of Indirect branches for which the target address was predicted incorrectly.

•Return

This metric provides the branch prediction outcome breakdown (correct, wrong path, wrong target) for return branches. Predicated off returns that are predicted as taken will be counted as wrong path outcomes.

◦Weight

Fraction of Return branches amongst all branch types.

◦Correct

Percentage of correctly predicted Return branches.

◦Wrong Path

Percentage of Return branches for which the target path (taken/not-taken) was predicted incorrectly.

◦Wrong Target

Percentage of Return branches for which the target address was predicted incorrectly.

c2c Event Set

Available only on Itanium 2 and dual-core Itanium 2 systems.

The c2c (“cache-to-cache”) event set provides information relating to cache coherence activity from the local processor perspective, the source of data for local data cache misses, and rate at which the local processor satisfies the data cache miss of remote processors.

If you use this event set, the default is to make the measurements irrespective of CPU operating state (that is, user, system, or interrupt states). By default, the idle state is not included in the measurement. You can use command-line options to limit the scope of the measurement. Specifically, you can:

•Limit measurement to a specific privilege level: -m event_set[:alluserkernel]

•Include idle: --exclude-idle False

•Exclude the interruption state: --measure-on-interrupts off

•Only measure the interruption state: --measure-on-interrupts only

Metrics Available from this Measurement

The following metrics are available from this event set. These descriptions do not take into account any command-line options you might use.

The metrics are:

•Snoop Count

Counts snoops from the CPU or non-CPU (all snoops) for one sampling period.

•Hitm Count

Counts the number of bus snoop requests from remote processors that hit a modified line in the local processor. Counts snoops from the CPU or non-CPU (all snoops).

•Avg Snoop Stall Cycles

This is the average number of bus clocks that the Front Side Bus (FSB) is stalled for a snoop.

222 Event Set Descriptions for CPU Metrics