libpfm_intel_snbep_unc_ubo - support for Intel Sandy Bridge-EP
U-Box uncore PMU
#include <perfmon/pfmlib.h>
PMU name: snbep_unc_ubo
PMU desc: Intel Sandy Bridge-EP U-Box uncore PMU
The library supports the Intel Sandy Bridge system configuration
unit (U-Box) uncore PMU. This PMU model only exists on Sandy Bridge model
45. There is only one U-Box PMU per processor socket.
The following modifiers are supported on Intel Sandy Bridge U-Box
uncore PMU:
- i
- Invert the meaning of the event. The counter will now count HA cycles in
which the event is not occurring. This is a boolean modifier
- e
- Enable edge detection, i.e., count only when there is a state transition
from no occurrence of the event to at least one occurrence. This modifier
must be combined with a threshold modifier (t) with a value greater or
equal to one. This is a boolean modifier.
- t
- Set the threshold value. When set to a non-zero value, the counter counts
the number of HA 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 [0:15].
- oi
- Invert the meaning of the occupancy event POWER_STATE_OCCUPANCY. The
counter will now count PCU cycles in which the event is not
occurring. This is a boolean modifier
- oe
- Enable edge detection for the occupancy event POWER_STATE_OCCUPANCY. The
event now counts only when there is a state transition from no occurrence
of the event to at least one occurrence. This modifier must be combined
with a threshold modifier (t) with a value greater or equal to one. This
is a boolean modifier.
- ff
- Enable frequency band filtering. This modifier applies only to the
UNC_P_FREQ_BANDx_CYCLES events, where x is [0-3]. The modifiers expects an
integer in the range [0-255]. The value is interpreted as a frequency
value to be multiplied by 100Mhz. Thus if the value is 32, then all cycles
where the processor is running at 3.2GHz and more are counted.
There are 3 events which support frequency band filtering, namely,
UNC_P_FREQ_BAND0_CYCLES, UNC_P_FREQ_BAND1_CYCLES, UNC_P_FREQ_BAND2_CYCLES,
UNC_P_FREQ_BAND3_CYCLES. The frequency filter (available via the ff
modifier) is stored into a PMU shared register which hold all 4 possible
frequency bands, one per event. However, the library generate the encoding
for each event individually because it processes events one at a time. The
caller or the underlying kernel interface may have to merge the band filter
settings to program the filter register properly.
Stephane Eranian <eranian@gmail.com>