libpfm_intel_ivb_unc(3) — Linux manual page


LIBPFM(3)               Linux Programmer's Manual              LIBPFM(3)

NAME         top

       libpfm_intel_ivb_unc - support for Intel Ivy Bridge uncore PMU

SYNOPSIS         top

       #include <perfmon/pfmlib.h>

       PMU name: ivb_unc_cbo0, ivb_unc_cbo1, ivb_unc_cbo2, ivb_unc_cbo3
       PMU desc: Intel Ivy Bridge C-box uncore

DESCRIPTION         top

       The library supports the Intel Ivy Bridge client part (model 58)
       uncore PMU.  The support is currently limited to the Coherency
       Box, so called C-Box for up to 4 physical cores.

       Each physical core has an associated C-Box which it uses to
       communicate with the L3 cache. The C-boxes all support the same
       set of events. However, Core 0 C-box (snb_unc_cbo0) supports an
       additional uncore clock ticks event: UNC_CLOCKTICKS.

MODIFIERS         top

       The following modifiers are supported on Intel Ivy Bridge C-Box
       uncore PMU:

       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 from no occurrence of the event to at
              least one occurrence. This modifier must be combined with
              a counter mask modifier (m) with a value greater or equal
              to one.  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].

       two umasks to be valid.  For UNC_CBO_CACHE_LOOKUP the first umask
       must be one of the MESI state umasks, the second has to be one of
       the filters.  For UNC_CBO_XSNP_RESPONSE the first umask must be
       one of the snoop types, the second has to be one of the filters.

AUTHORS         top

       Stephane Eranian <>

COLOPHON         top

       This page is part of the perfmon2 (a performance monitoring
       library) project.  Information about the project can be found at
       ⟨⟩.  If you have a bug report for
       this manual page, send it to  This page was obtained
       from the project's upstream Git repository
       ⟨git:// perfmon2-libpfm4⟩ on
       2021-08-27.  (At that time, the date of the most recent commit
       that was found in the repository was 2021-08-04.)  If you
       discover any rendering problems in this HTML version of the page,
       or you believe there is a better or more up-to-date source for
       the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original
       manual page), send a mail to

                               June, 2013                      LIBPFM(3)