NAME | SYNOPSIS | DESCRIPTION | MODIFIERS | OFFCORE_RESPONSE events | AUTHORS | COLOPHON

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

NAME         top

       libpfm_intel_slm - support for Intel Silvermont core PMU

SYNOPSIS         top

       #include <perfmon/pfmlib.h>

       PMU name: slm
       PMU desc: Intel Silvermont

DESCRIPTION         top

       The library supports the Intel Silvermont core PMU.

MODIFIERS         top

       The following modifiers are supported on Intel Silvermont processors:

       u      Measure at user level which includes privilege levels 1, 2, 3.
              This corresponds to PFM_PLM3.  This is a boolean modifier.

       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 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].

OFFCORE_RESPONSE events         top

       Intel Silvermont provides two offcore_response events:
       OFFCORE_RESPONSE_0 and OFFCORE_RESPONSE_1.

       Those events need special treatment in the performance monitoring
       infrastructure because each event uses an extra register to store
       some settings. Thus, in case multiple offcore_response events are
       monitored simultaneously, the kernel needs to manage the sharing of
       that extra register.

       The offcore_response events are exposed as a normal event by the
       library. The extra settings are exposed as regular umasks. The
       library takes care of encoding the events according to the underlying
       kernel interface.

       On Intel Silvermont, the umasks are divided into three categories:
       request, supplier and snoop. The user must provide at least one umask
       for each category. The categories are shown in the umask
       descriptions. The library provides a default umask per category if
       not provided by the user.

       There is also the special response umask called ANY_RESPONSE. When
       this umask is used then it overrides any supplier and snoop umasks.
       In other words, users can specify either ANY_RESPONSE OR any
       combinations of supplier + snoops.

       In case no supplier or snoop is specified, the library defaults to
       using ANY_RESPONSE.

       For instance, the following are valid event selections:

       OFFCORE_RESPONSE_0:DMND_DATA_RD:ANY_RESPONSE

       OFFCORE_RESPONSE_0:ANY_REQUEST

       OFFCORE_RESPONSE_0:ANY_RFO:LLC_HITM:SNOOP_ANY

       But the following are illegal:

       OFFCORE_RESPONSE_0:ANY_RFO:NON_DRAM:ANY_RESPONSE

       OFFCORE_RESPONSE_0:ANY_RFO:L2_HIT:SNOOP_ANY:ANY_RESPONSE

AUTHORS         top

       Stephane Eranian <eranian@gmail.com>

COLOPHON         top

       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 perfmon2-devel@lists.sourceforge.net.  This
       page was obtained from the project's upstream Git repository 
       ⟨git://git.code.sf.net/p/perfmon2/libpfm4⟩ on 2017-05-03.  If you dis‐
       cover 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 man-pages@man7.org

                               November, 2013                      LIBPFM(3)