The library supports any processor implementing the Intel
architectural PMU. This is a minimal PMU with a variable number
of counters but predefined set of events. It is implemented in
all recent processors starting with Intel Core Duo/Core Solo.
It acts as a default PMU support in case the library is run on a
very recent processor for which the specific support has not yet
The following modifiers are supported on Intel architectural PMU:
u Measure at user level which includes privilege levels 1,
2, 3. This corresponds to PFM_PLM3. This is a boolean
k Measure at kernel level which includes privilege level 0.
This corresponds to PFM_PLM0. This is a boolean modifier.
i Invert the meaning of the event. The counter will now
count 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. This is a boolean modifier.
c 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].
t Measure on both threads at the same time assuming hyper-
threading is enabled. This modifier requires at least
version 3 of the architectural PMU. This is a boolean
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 perfmon2-libpfm4⟩ on
2021-04-01. (At that time, the date of the most recent commit
that was found in the repository was 2021-03-23.) If you
discover any rendering problems in this HTML version of the page,
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September, 2009 LIBPFM(3)