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pmc.iaf(3) [freebsd man page]

PMC.IAF(3)						   BSD 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.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 <jkoshy@FreeBSD.org>. BSD
November 14, 2008 BSD

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PMC_CAPABILITIES(3)					   BSD Library Functions Manual 				       PMC_CAPABILITIES(3)

NAME
pmc_capabilities, pmc_cpuinfo, pmc_ncpu, pmc_npmc, pmc_pmcinfo, pmc_width -- retrieve information about performance monitoring counters LIBRARY
Performance Counters Library (libpmc, -lpmc) SYNOPSIS
#include <pmc.h> int pmc_capabilities(pmc_id_t pmc, uint32_t *caps); int pmc_cpuinfo(const struct pmc_cpuinfo **cpu_info); int pmc_ncpu(void); int pmc_npmc(int cpu); int pmc_pmcinfo(int cpu, struct pmc_pmcinfo **pmc_info); int pmc_width(pmc_id_t pmc, uint32_t *width); DESCRIPTION
These functions retrieve information about performance monitoring hardware. Function pmc_capabilities() retrieves the hardware capabilities of a PMC. Argument pmc is a PMC handle obtained by a prior call to pmc_allocate(). The function sets argument caps to a bit mask of capabilities supported by the PMC denoted by argument pmc. PMC capabili- ties are described in pmc(3). Function pmc_cpuinfo() retrieves information about the CPUs in the system. Argument cpu_info will be set to point to an internal structure with information about the system's CPUs. The caller should not free this pointer value. This structure has the following fields: pm_cputype Specifies the CPU type. pm_ncpu Specifies the number of CPUs in the system. pm_npmc Specifies the number of PMC rows per CPU. pm_nclass Specifies the number of distinct classes of PMCs in the system. pm_classes Contains an array of struct pmc_classinfo descriptors describing the properties of each class of PMCs in the system. Function pmc_ncpu() is a convenience function that returns the maximum CPU number in the system. On systems that support sparsely numbered CPUs, not all CPUs may be physically present. Applications need to be prepared to deal with nonexistent CPUs. Function pmc_npmc() is a convenience function that returns the number of PMCs available in the CPU specified by argument cpu. Function pmc_pmcinfo() returns information about the current state of the PMC hardware in the CPU specified by argument cpu. The location specified by argument pmc_info is set to point an array of struct pmc_info structures each describing the state of one PMC in the CPU. These structure contain the following fields: pm_name A human readable name for the PMC. pm_class The PMC class for the PMC. pm_enabled Non-zero if the PMC is enabled. pm_rowdisp The disposition of the PMC row for this PMC. Row dispositions are documented in hwpmc(4). pm_ownerpid If the hardware is in use, the process id of the owner of the PMC. pm_mode The PMC mode as described in pmc(3). pm_event If the hardware is in use, the PMC event being measured. pm_flags If the hardware is in use, the flags associated with the PMC. pm_reloadcount For sampling PMCs, the reload count associated with the PMC. Function pmc_width() is used to retrieve the width in bits of the hardware counters associated with a PMC. Argument pmc is a PMC handle obtained by a prior call to pmc_allocate(). The function sets the location pointed to by argument width to the width of the physical coun- ters associated with PMC pmc. RETURN VALUES
Functions pmc_ncpu() and pmc_npmc() returns a positive integer if successful; otherwise the value -1 is returned and the global variable errno is set to indicate the error. Functions pmc_capabilities(), pmc_cpuinfo(), pmc_pmcinfo() and pmc_width() return 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indicate the error. ERRORS
A call to function pmc_capabilities() may fail with the following errors: [EINVAL] The argument to the function was invalid. Calls to functions pmc_cpuinfo(), pmc_ncpu() and pmc_npmc() may fail with the following errors: [ENXIO] A prior call to pmc_init() to initialize the PMC library had failed. A call to function pmc_pmcinfo() may fail with the following errors: [EINVAL] The argument cpu was invalid. [ENXIO] The argument cpu specified a disabled or absent CPU. A call to function pmc_width() may fail with the following errors: [EINVAL] The argument to the function was invalid. SEE ALSO
pmc(3), pmc_allocate(3), pmc_get_driver_stats(3), pmc_name_of_capability(3), pmc_name_of_class(3), pmc_name_of_cputype(3), pmc_name_of_event(3), pmc_name_of_mode(3), hwpmc(4) BSD
September 22, 2008 BSD
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