The following modifiers are supported on Intel Ivy Bridge PCU uncore
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
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].
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_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.
This page is part of the perfmon2 (a performance monitoring library)
project. Information about the project can be found at
⟨http://perfmon2.sourceforge.net/⟩. If you have a bug report for this
manual page, send it to email@example.com. This
page was obtained from the project's upstream Git repository
⟨git://git.code.sf.net/p/perfmon2/libpfm4⟩ on 2017-03-13. If you dis‐
cover any rendering problems in this HTML version of the page, or you
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you have corrections or improvements to the information in this
COLOPHON (which is not part of the original manual page), send a mail
February, 2014 LIBPFM(3)