PMC.IAF(3)             FreeBSD Library Functions Manual             PMC.IAF(3)

NAME
     pmc.iaf - measurement events for Intel fixed function performance
     counters.

LIBRARY
     Performance Counters Library (libpmc, -lpmc)

SYNOPSIS
     #include <pmc.h>

DESCRIPTION
     Intel fixed-function PMCs are present in CPUs that conform to version 2
     or later of the Intel Performance Measurement Architecture.  Each fixed-
     function PMC measures a specific hardware event.  The number of fixed-
     function PMCs implemented in a CPU can vary.  The number of fixed-
     function PMCs present can be determined at runtime by using function
     pmc_cpuinfo(3).

     Intel fixed-function PMCs are documented in Volume 3: System Programming
     Guide, IA-32 Intel(R) Architecture Software Developer's Manual, Order
     Number 253669-027US, Intel Corporation, July 2008.

   PMC Capabilities
     Fixed-function PMCs support the following capabilities:

     Capability           Support
     PMC_CAP_CASCADE      No
     PMC_CAP_EDGE         No
     PMC_CAP_INTERRUPT    Yes
     PMC_CAP_INVERT       No
     PMC_CAP_READ         Yes
     PMC_CAP_PRECISE      No
     PMC_CAP_SYSTEM       Yes
     PMC_CAP_TAGGING      No
     PMC_CAP_THRESHOLD    No
     PMC_CAP_USER         Yes
     PMC_CAP_WRITE        Yes

   Class Name Prefix
     These PMCs are named using a class name prefix of "iaf-".

   Event Qualifiers (Fixed Function PMCs)
     These PMCs support the following modifiers:

     os      Configure the PMC to count events occurring at ring level 0.

     usr     Configure the PMC to count events occurring at ring levels 1, 2
             or 3.

     anythread
             (Atom CPUs) Configure the PMC to count events on all logical
             processors sharing a processor core.  The default is to count
             events on the current logical processor.

     If neither of the "os" or "usr" qualifiers are specified, the default is
     to enable both.

   Event Specifiers (Fixed Function PMCs)
     The fixed function PMCs are selectable using the following event names:

     INSTR_RETIRED.ANY
             (Fixed Function Counter 0) The number of instructions retired.

     CPU_CLK_UNHALTED.CORE
             (Fixed Function Counter 1) The number of core cycles for which
             the core is not halted.

     CPU_CLK_UNHALTED.REF
             (Fixed Function Counter 2) The number of reference cycles for
             which the core is not halted.

EXAMPLES
     To measure the number of core cycles for which the core was not halted
     use the event specifier "iaf-cpu-clk-unhalted.core".

     To measure the number of user instructions retired use the event
     specifier "iaf-instr-retired.any,usr".

     To measure the number of user instructions retired on all logical
     processors in an Atom CPU, use the event specifier
     "iaf-instr-retired.any,usr,anythread".

SEE ALSO
     pmc(3), pmc.atom(3), pmc.core(3), pmc.core2(3), pmc.k7(3), pmc.k8(3),
     pmc.soft(3), pmc.tsc(3), pmc_cpuinfo(3), pmclog(3), hwpmc(4)

HISTORY
     The pmc library first appeared in FreeBSD 6.0.

AUTHORS
     The Performance Counters Library (libpmc, -lpmc) library was written by
     Joseph Koshy <jkoshy@FreeBSD.org>.

FreeBSD 13.1-RELEASE-p6        November 14, 2008       FreeBSD 13.1-RELEASE-p6