libpfm_intel_nhm_unc man page


#include <perfmon/pfmlib.h>

PMU name: nhm_unc
PMU desc: Intel Nehalem uncore


The library supports the Nehalem uncore PMU as implemented by processors such as Intel Core i7, and Intel Core i5.

The PMU is located at the socket-level and is therefore shared between the various cores. By construction it can only measure at all privilege levels.


The following modifiers are supported on Intel Nehalem processors:

Invert the meaning of the event. The counter will now count cycles in which the event is not occurring. This is a boolean modifier
Enable edge detection, i.e., count only when there is a state transition. This is a boolean modifier.
Set the counter mask value. The mask acts as a threshold. The counter will count the number of cycles in which the number of occurrences of the event is greater or equal to the threshold. This is an integer modifier with values in the range [0:255].
Causes the queue occupancy counter associated with the event to be cleared (zeroed). This is a boolean modifier.


Stephane Eranian <eranian@gmail.com>

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