freebsd-nq/lib/libpmc/pmc.iaf.3

.\" Copyright (c) 2008 Joseph Koshy.  All rights reserved.
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.\" This software is provided by Joseph Koshy ``as is'' and
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.\" $FreeBSD$
.\"
.Dd November 14, 2008
.Os
.Dt PMC.IAF 3
.Sh NAME
.Nm pmc.iaf
.Nd measurement events for
.Tn Intel
fixed function performance counters.
.Sh LIBRARY
.Lb libpmc
.Sh SYNOPSIS
.In pmc.h
.Sh DESCRIPTION
.Tn Intel
fixed-function PMCs are present in CPUs that conform to version 2 or
later of the
.Tn 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
.Xr pmc_cpuinfo 3 .
.Pp
Intel fixed-function PMCs are documented in
.Rs
.%B "IA-32 Intel(R) Architecture Software Developer's Manual"
.%T "Volume 3: System Programming Guide"
.%N "Order Number 253669-027US"
.%D July 2008
.%Q "Intel Corporation"
.Re
.Pp
.Ss PMC Capabilities
Fixed-function PMCs support the following capabilities:
.Bl -column "PMC_CAP_INTERRUPT" "Support"
.It Em Capability Ta Em Support
.It PMC_CAP_CASCADE Ta \&No
.It PMC_CAP_EDGE Ta \&No
.It PMC_CAP_INTERRUPT Ta Yes
.It PMC_CAP_INVERT Ta \&No
.It PMC_CAP_READ Ta Yes
.It PMC_CAP_PRECISE Ta \&No
.It PMC_CAP_SYSTEM Ta Yes
.It PMC_CAP_TAGGING Ta \&No
.It PMC_CAP_THRESHOLD Ta \&No
.It PMC_CAP_USER Ta Yes
.It PMC_CAP_WRITE Ta Yes
.El
.Ss Class Name Prefix
These pmcs are named using a class name prefix of
.Dq Li iaf- .
.Ss Event Qualifiers (Fixed Function PMCs)
These PMCs support the following modifiers:
.Bl -tag -width indent
.It Li os
Configure the PMC to count events occurring at ring level 0.
.It Li usr
Configure the PMC to count events occurring at ring levels 1, 2
or 3.
.It Li anythread
.Pq Tn 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.
.El
.Pp
If neither of the
.Dq Li os
or
.Dq Li usr
qualifiers are specified, the default is to enable both.
.Ss Event Specifiers (Fixed Function PMCs)
The fixed function PMCs are selectable using the following
event names:
.Bl -tag -width indent
.It Li INSTR_RETIRED.ANY
.Pq Fixed Function Counter 0
The number of instructions retired.
.It Li CPU_CLK_UNHALTED.CORE
.Pq Fixed Function Counter 1
The number of core cycles for which the core is not halted.
.It Li CPU_CLK_UNHALTED.REF
.Pq Fixed Function Counter 2
The number of reference cycles for which the core is not halted.
.El
.Sh EXAMPLES
To measure the number of core cycles for which the core was not halted
use the event specifier
.Qq iaf-cpu-clk-unhalted.core .
.Pp
To measure the number of user instructions retired use the event specifier
.Qq iaf-instr-retired.any,usr .
.Pp
To measure the number of user instructions retired on all logical processors
in an
.Tn Atom
CPU, use the event specifier
.Qq iaf-instr-retired.any,usr,anythread .
.Sh SEE ALSO
.Xr pmc 3 ,
.Xr pmc.atom 3 ,
.Xr pmc.core 3 ,
.Xr pmc.core2 3 ,
.Xr pmc.k7 3 ,
.Xr pmc.k8 3 ,
.Xr pmc.p4 3 ,
.Xr pmc.p5 3 ,
.Xr pmc.p6 3 ,
.Xr pmc.tsc 3 ,
.Xr pmc_cpuinfo 3 ,
.Xr pmclog 3 ,
.Xr hwpmc 4
.Sh HISTORY
The
.Nm pmc
library first appeared in
.Fx 6.0 .
.Sh AUTHORS
The
.Lb libpmc
library was written by
.An "Joseph Koshy"
.Aq jkoshy@FreeBSD.org .