tail head cat sleep
QR code linking to this page

Manual Pages  — PMC.IAF

NAME

pmc.iaf – measurement events for Intel fixed function performance counters.

CONTENTS

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

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

PMC Capabilities

Fixed-function PMCs support the following capabilities:
Capability Support

PMC_CAP_CASCADE
amp;No

PMC_CAP_EDGE
amp;No

PMC_CAP_INTERRUPT
Yes

PMC_CAP_INVERT
amp;No

PMC_CAP_READ
Yes

PMC_CAP_PRECISE
amp;No

PMC_CAP_SYSTEM
Yes

PMC_CAP_TAGGING
amp;No

PMC_CAP_THRESHOLD
amp;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.p4(3), pmc.p5(3), pmc.p6(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 <Mt jkoshy@FreeBSD.org>.

PMC.IAF (3) November 14, 2008

tail head cat sleep
QR code linking to this page


Please direct any comments about this manual page service to Ben Bullock. Privacy policy.

Not only is UNIX dead, it's starting to smell really bad.
— Rob Pike