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Man Pages


Manual Reference Pages  - PMC (3)

NAME

pmc_allocate, pmc_attach, pmc_capabilities, pmc_configure_logfile, pmc_cpuinfo, pmc_detach, pmc_disable, pmc_enable, pmc_event_names_of_class, pmc_flush_logfile, pmc_get_driver_stats, pmc_get_msr, pmc_init, pmc_name_of_capability, pmc_name_of_class, pmc_name_of_cputype, pmc_name_of_event, pmc_name_of_mode, pmc_name_of_state, pmc_ncpu, pmc_npmc, pmc_pmcinfo, pmc_read, pmc_release, pmc_rw, pmc_set, pmc_start, pmc_stop, pmc_width, pmc_write, pmc_writelog - programming API for using hardware performance monitoring counters

CONTENTS

Library
Synopsis
Description
     Application Programming Interface
     Signal Handling Requirements
     Convenience Functions
     Administration
Event Specifiers
     Event Name Aliases
     Time Stamp Counter (TSC)
     AMD (K7) PMCs
     AMD (K8) PMCs
     Intel P6 PMCS
     Intel P4 PMCS
Implementation Notes
Return Values
Compatibility
Errors
See Also
History
Bugs

LIBRARY


.Lb libpmc

SYNOPSIS


.In pmc.h int
.Fo pmc_allocate const char *eventspecifier enum pmc_mode mode uint32_t flags uint32_t cpu pmc_id_t *pmcid
.Fc int pmc_attach pmc_id_t pmcid pid_t pid int pmc_capabilities pmc_id_t pmc uint32_t *caps int pmc_configure_logfile int fd int pmc_cpuinfo const struct pmc_cpuinfo **cpu_info int pmc_detach pmc_id_t pmcid pid_t pid int pmc_disable uint32_t cpu int pmc int pmc_enable uint32_t cpu int pmc int
.Fo pmc_event_names_of_class enum pmc_class cl const char ***eventnames int *nevents
.Fc int pmc_flush_logfile void int pmc_get_driver_stats struct pmc_driverstats *gms int pmc_get_msr pmc_id_t pmc uint32_t *msr int pmc_init void const char * pmc_name_of_capability enum pmc_caps pc const char * pmc_name_of_class enum pmc_class pc const char * pmc_name_of_cputype enum pmc_cputype ct const char * pmc_name_of_disposition enum pmc_disp pd const char * pmc_name_of_event enum pmc_event pe const char * pmc_name_of_mode enum pmc_mode pm const char * pmc_name_of_state enum pmc_state ps int pmc_ncpu void int pmc_npmc uint32_t cpu int pmc_pmcinfo uint32_t cpu struct pmc_pmcinfo **pmc_info int pmc_read pmc_id_t pmc pmc_value_t *value int pmc_release pmc_id_t pmc int pmc_rw pmc_id_t pmc pmc_value_t newvalue pmc_value_t *oldvaluep int pmc_set pmc_id_t pmc pmc_value_t value int pmc_start pmc_id_t pmc int pmc_stop pmc_id_t pmc int pmc_write pmc_id_t pmc pmc_value_t value int pmc_writelog uint32_t userdata int pmc_width pmc_id_t pmc uint32_t *width

DESCRIPTION

These functions implement a high-level library for using the system’s hardware performance counters.

PMCs are allocated using pmc_allocate, released using pmc_release and read using pmc_read. Allocated PMCs may be started or stopped at any time using pmc_start and pmc_stop respectively. An allocated PMC may be of "global" scope, meaning that the PMC measures system-wide events, or "process-private" scope, meaning that the PMC only counts hardware events when the allocating process (or, optionally, its children) are active.

PMCs may further be in "counting mode", or in "sampling mode". Sampling mode PMCs deliver an interrupt to the CPU after a configured number of hardware events have been seen. A process-private sampling mode PMC will cause its owner process to get periodic SIGPROF interrupts, while a global sampling mode PMC is used to do system-wide statistical sampling (see hwpmc(4)). The sampling rate desired of a sampling-mode PMC is set using pmc_set. Counting mode PMCs do not interrupt the CPU; their values can be read using pmc_read.

System-wide statistical sampling is configured by allocating at least one sampling mode PMC with global scope, and when a log file is configured using pmc_configure_logfile. The hwpmc(4) driver manages system-wide statistical sampling; for more information please see hwpmc(4).

    Application Programming Interface

The function pmc_init initializes the pmc(3) library. This function must be called first, before any of the other functions in the library.

The function pmc_allocate allocates a counter that counts the events named by eventspecifier, and writes the allocated counter ID to *pmcid. Argument eventspecifier comprises an PMC event name followed by an optional comma separated list of keywords and qualifiers. The allowed syntax for eventspecifier is processor architecture specific and is listed in section EVENT SPECIFIERS below. The desired PMC mode is specified by mode, and any mode specific modifiers are specified using flags. The cpu argument is the value PMC_CPU_ANY, or names the CPU the allocation is to be on. Requesting a specific CPU only makes sense for global PMCs; process-private PMC allocations should always specify PMC_CPU_ANY.

By default, a PMC configured in process-virtual counting mode is set up to profile its owner process. The function pmc_attach may be used to attach the PMC to a different process. It needs to be called before the counter is first started with pmc_start. The function pmc_detach may be used to detach a PMC from a process it was attached to using a prior call to pmc_attach.

The function pmc_release releases a PMC previously allocated with pmc_allocate. This function call implicitly detaches the PMC from all its target processes.

An allocated PMC may be started and stopped using pmc_start and pmc_stop respectively.

The current value of a PMC may be read with pmc_read and written using pmc_write, provided the underlying hardware supports these operations on the allocated PMC. The read and write operation may be combined using pmc_rw.

The function pmc_capabilities sets argument caps to a bitmask of capabilities supported by the PMC denoted by argument pmc. The function pmc_width sets argument width to the width of the PMC denoted by argument pmc.

The pmc_configure_logfile function causes the hwpmc(4) driver to log performance data to file corresponding to the process’ file handle fd. If argument fd is -1, then any previously configured logging is reset and all data queued to be written are discarded.

The pmc_flush_logfile function will send all data queued inside the hwpmc(4) driver to the configured log file before returning. The pmc_writelog function will append a log entry containing the argument userdata to the log file.

The function pmc_set configures a sampling PMC pmc to interrupt every value events. For counting PMCs, pmc_set sets the initial value of the PMC to value.

The function pmc_get_driver_statistics copies a snapshot of the usage statistics maintained by hwpmc(4) into the memory area pointed to by argument gms.

    Signal Handling Requirements

Applications using PMCs are required to handle the following signals:
SIGBUS
  When the hwpmc(4) module is unloaded using kldunload(8), processes that have PMCs allocated to them will be sent a SIGBUS signal.
SIGIO The hwpmc(4) driver will send a PMC owning process a SIGIO signal if:
  • If any process-mode PMC allocated by it loses all its target processes.
  • If the driver encounters an error when writing log data to a configured log file. This error may be retrieved by a subsequent call to pmc_flush_logfile.

    Convenience Functions

The function pmc_ncpu returns the number of CPUs present in the system.

The function pmc_npmc returns the number of PMCs supported on CPU cpu. The function pmc_cpuinfo sets argument cpu_info to point to a structure with information about the system’s CPUs. Function pmc_pmcinfo returns information about the current state of CPU cpu ’s PMCs. This function sets argument *pmc_info to point to a memory area allocated with calloc(3). The caller is expected to free the area when done.

The functions pmc_name_of_capability, pmc_name_of_class, pmc_name_of_cputype, pmc_name_of_disposition, pmc_name_of_event, pmc_name_of_mode and pmc_name_of_state are useful for code wanting to print error messages. They return
.Vt const char * pointers to human-readable representations of their arguments. These return values should not be freed using free(3).

The function pmc_event_names_of_class returns a list of event names supported by a given PMC class cl. On successful return, an array of
.Vt const char * pointers to the names of valid events supported by class cl is allocated by the library using malloc(3), and a pointer to this array is returned in the location pointed to by eventnames. The number of pointers allocated is returned in the location pointed to by nevents.

    Administration

Individual PMCs may be enabled or disabled on a given CPU using pmc_enable and pmc_disable respectively. For these functions, cpu is the CPU number, and pmc is the index of the PMC to be operated on. Only the super-user is allowed to enable and disable PMCs.

    x86 Architecture Specific API

The pmc_get_msr function returns the processor model specific register number associated with pmc. Applications may use the x86 RDPMC instruction to directly read the contents of the PMC.

EVENT SPECIFIERS

Event specifiers are strings comprising of an event name, followed by optional parameters modifying the semantics of the hardware event being probed. Event names are PMC architecture dependent, but the hwpmc(4) library defines machine independent aliases for commonly used events.

    Event Name Aliases

Event name aliases are CPU architecture independent names for commonly used events. The following aliases are known to this version of the pmc(3) library:
branches
  Measure the number of branches retired.
branch-mispredicts
  Measure the number of retired branches that were mispredicted.
cycles
  Measure processor cycles. This event is implemented using the processor’s Time Stamp Counter register.
dc-misses
  Measure the number of data cache misses.
ic-misses
  Measure the number of instruction cache misses.
instructions
  Measure the number of instructions retired.
interrupts
  Measure the number of interrupts seen.
unhalted-cycles
  Measure the number of cycles the processor is not in a halted or sleep state.

    Time Stamp Counter (TSC)

The timestamp counter is a monotonically non-decreasing counter that counts processor cycles.

In the i386 architecture, this counter may be selected by requesting an event with event specifier "tsc". The "tsc" event does not support any further qualifiers. It can only be allocated in system-wide counting mode, and is a read-only counter. Multiple processes are allowed to allocate the TSC. Once allocated, it may be read using the pmc_read function, or by using the RDTSC instruction.

    AMD (K7) PMCs

These PMCs are present in the AMD Athlon series of CPUs and are documented in:
.Rs
.Re

Event specifiers for AMD K7 PMCs can have the following optional qualifiers:
count= value
  Configure the counter to increment only if the number of configured events measured in a cycle is greater than or equal to value.
edge Configure the counter to only count negated-to-asserted transitions of the conditions expressed by the other qualifiers. In other words, the counter will increment only once whenever a given condition becomes true, irrespective of the number of clocks during which the condition remains true.
inv Invert the sense of comparision when the "count" qualifier is present, making the counter to increment when the number of events per cycle is less than the value specified by the "count" qualifier.
os Configure the PMC to count events happening at privilege level 0.
unitmask= mask
  This qualifier is used to further qualify a select few events, "k7-dc-refills-from-l2", "k7-dc-refills-from-system" and "k7-dc-writebacks". Here mask is a string of the following characters optionally separated by +’ characters:

m Count operations for lines in the "Modified" state.
o Count operations for lines in the "Owner" state.
e Count operations for lines in the "Exclusive" state.
s Count operations for lines in the "Shared" state.
i Count operations for lines in the "Invalid" state.

If no "unitmask" qualifier is specified, the default is to count events for caches lines in any of the above states.
usr Configure the PMC to count events occurring at privilege levels 1, 2 or 3.

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

The event specifiers supported on AMD K7 PMCs are:
k7-dc-accesses
  Count data cache accesses.
k7-dc-misses
  Count data cache misses.
k7-dc-refills-from-l2 [,unitmask= mask]
  Count data cache refills from L2 cache. This event may be further qualified using the "unitmask" qualifier.
k7-dc-refills-from-system [,unitmask= mask]
  Count data cache refills from system memory. This event may be further qualified using the "unitmask" qualifier.
k7-dc-writebacks [,unitmask= mask]
  Count data cache writebacks. This event may be further qualified using the "unitmask" qualifier.
k7-l1-dtlb-miss-and-l2-dtlb-hits
  Count L1 DTLB misses and L2 DTLB hits.
k7-l1-and-l2-dtlb-misses
  Count L1 and L2 DTLB misses.
k7-misaligned-references
  Count misaligned data references.
k7-ic-fetches
  Count instruction cache fetches.
k7-ic-misses
  Count instruction cache misses.
k7-l1-itlb-misses
  Count L1 ITLB misses that are L2 ITLB hits.
k7-l1-l2-itlb-misses
  Count L1 (and L2) ITLB misses.
k7-retired-instructions
  Count all retired instructions.
k7-retired-ops
  Count retired ops.
k7-retired-branches
  Count all retired branches (conditional, unconditional, exceptions and interrupts).
k7-retired-branches-mispredicted
  Count all misprediced retired branches.
k7-retired-taken-branches
  Count retired taken branches.
k7-retired-taken-branches-mispredicted
  Count mispredicted taken branches that were retired.
k7-retired-far-control-transfers
  Count retired far control transfers.
k7-retired-resync-branches
  Count retired resync branches (non control transfer branches).
k7-interrupts-masked-cycles
  Count the number of cycles when the processor’s IF flag was zero.
k7-interrupts-masked-while-pending-cycles
  Count the number of cycles interrupts were masked while pending due to the processor’s IF flag being zero.
k7-hardware-interrupts
  Count the number of taken hardware interrupts.

    AMD (K8) PMCs

These PMCs are present in the AMD Athlon64 and AMD Opteron series of CPUs. They are documented in:
.Rs
.Re

Event specifiers for AMD K8 PMCs can have the following optional qualifiers:
count= value
  Configure the counter to increment only if the number of configured events measured in a cycle is greater than or equal to value.
edge Configure the counter to only count negated-to-asserted transitions of the conditions expressed by the other fields. In other words, the counter will increment only once whenever a given condition becomes true, irrespective of the number of clocks during which the condition remains true.
inv Invert the sense of comparision when the "count" qualifier is present, making the counter to increment when the number of events per cycle is less than the value specified by the "count" qualifier.
mask= qualifier
  Many event specifiers for AMD K8 PMCs need to be additionally qualified using a mask qualifier. These additional qualifiers are event-specific and are documented along with their associated event specifiers below.
os Configure the PMC to count events happening at privilege level 0.
usr Configure the PMC to count events occurring at privilege levels 1, 2 or 3.

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

The event specifiers supported on AMD K8 PMCs are:
k8-bu-cpu-clk-unhalted
  Count the number of clock cycles when the CPU is not in the HLT or STPCLK states.
k8-bu-fill-request-l2-miss [,mask= qualifier]
  Count fill requests that missed in the L2 cache. This event may be further qualified using qualifier, which is a +’ separated set of the following keywords:

dc-fill
  Count data cache fill requests.
ic-fill
  Count instruction cache fill requests.
tlb-reload
  Count TLB reloads.

The default is to count all types of requests.
k8-bu-internal-l2-request [,mask= qualifier]
  Count internally generated requests to the L2 cache. This event may be further qualified using qualifier, which is a +’ separated set of the following keywords:

cancelled
  Count cancelled requests.
dc-fill
  Count data cache fill requests.
ic-fill
  Count instruction cache fill requests.
tag-snoop
  Count tag snoop requests.
tlb-reload
  Count TLB reloads.

The default is to count all types of requests.
k8-dc-access
  Count data cache accesses including microcode scratchpad accesses.
k8-dc-copyback [,mask= qualifier]
  Count data cache copyback operations. This event may be further qualified using qualifier, which is a +’ separated set of the following keywords:

exclusive
  Count operations for lines in the "exclusive" state.
invalid
  Count operations for lines in the "invalid" state.
modified
  Count operations for lines in the "modified" state.
owner Count operations for lines in the "owner" state.
shared
  Count operations for lines in the "shared" state.

The default is to count operations for lines in all the above states.
k8-dc-dcache-accesses-by-locks [,mask= qualifier]
  Count data cache accesses by lock instructions. This event is only available on processors of revision C or later vintage. This event may be further qualified using qualifier, which is a +’ separated set of the following keywords:

accesses
  Count data cache accesses by lock instructions.
misses
  Count data cache misses by lock instructions.

The default is to count all accesses.
k8-dc-dispatched-prefetch-instructions [,mask= qualifier]
  Count the number of dispatched prefetch instructions. This event may be further qualified using qualifier, which is a +’ separated set of the following keywords:

load Count load operations.
nta Count non-temporal operations.
store Count store operations.

The default is to count all operations.
k8-dc-l1-dtlb-miss-and-l2-dtlb-hit
  Count L1 DTLB misses that are L2 DTLB hits.
k8-dc-l1-dtlb-miss-and-l2-dtlb-miss
  Count L1 DTLB misses that are also misses in the L2 DTLB.
k8-dc-microarchitectural-early-cancel-of-an-access
  Count microarchitectural early cancels of data cache accesses.
k8-dc-microarchitectural-late-cancel-of-an-access
  Count microarchitectural late cancels of data cache accesses.
k8-dc-misaligned-data-reference
  Count misaligned data references.
k8-dc-miss
  Count data cache misses.
k8-dc-one-bit-ecc-error [,mask= qualifier]
  Count one bit ECC errors found by the scrubber. This event may be further qualified using qualifier, which is a +’ separated set of the following keywords:

scrubber
  Count scrubber detected errors.
piggyback
  Count piggyback scrubber errors.

The default is to count both kinds of errors.
k8-dc-refill-from-l2 [,mask= qualifier]
  Count data cache refills from L2 cache. This event may be further qualified using qualifier, which is a +’ separated set of the following keywords:

exclusive
  Count operations for lines in the "exclusive" state.
invalid
  Count operations for lines in the "invalid" state.
modified
  Count operations for lines in the "modified" state.
owner Count operations for lines in the "owner" state.
shared
  Count operations for lines in the "shared" state.

The default is to count operations for lines in all the above states.
k8-dc-refill-from-system [,mask= qualifier]
  Count data cache refills from system memory. This event may be further qualified using qualifier, which is a +’ separated set of the following keywords:

exclusive
  Count operations for lines in the "exclusive" state.
invalid
  Count operations for lines in the "invalid" state.
modified
  Count operations for lines in the "modified" state.
owner Count operations for lines in the "owner" state.
shared
  Count operations for lines in the "shared" state.

The default is to count operations for lines in all the above states.
k8-fp-dispatched-fpu-ops [,mask= qualifier]
  Count the number of dispatched FPU ops. This event is supported in revision B and later CPUs. This event may be further qualified using qualifier, which is a +’ separated set of the following keywords:

add-pipe-excluding-junk-ops
  Count add pipe ops excluding junk ops.
add-pipe-junk-ops
  Count junk ops in the add pipe.
multiply-pipe-excluding-junk-ops
  Count multiply pipe ops excluding junk ops.
multiply-pipe-junk-ops
  Count junk ops in the multiply pipe.
store-pipe-excluding-junk-ops
  Count store pipe ops excluding junk ops
store-pipe-junk-ops
  Count junk ops in the store pipe.

The default is to count all types of ops.
k8-fp-cycles-with-no-fpu-ops-retired
  Count cycles when no FPU ops were retired. This event is supported in revision B and later CPUs.
k8-fp-dispatched-fpu-fast-flag-ops
  Count dispatched FPU ops that use the fast flag interface. This event is supported in revision B and later CPUs.
k8-fr-decoder-empty
  Count cycles when there was nothing to dispatch (i.e., the decoder was empty).
k8-fr-dispatch-stalls
  Count all dispatch stalls.
k8-fr-dispatch-stall-for-segment-load
  Count dispatch stalls for segment loads.
k8-fr-dispatch-stall-for-serialization
  Count dispatch stalls for serialization.
k8-fr-dispatch-stall-from-branch-abort-to-retire
  Count dispatch stalls from branch abort to retiral.
k8-fr-dispatch-stall-when-fpu-is-full
  Count dispatch stalls when the FPU is full.
k8-fr-dispatch-stall-when-ls-is-full
  Count dispatch stalls when the load/store unit is full.
k8-fr-dispatch-stall-when-reorder-buffer-is-full
  Count dispatch stalls when the reorder buffer is full.
k8-fr-dispatch-stall-when-reservation-stations-are-full
  Count dispatch stalls when reservation stations are full.
k8-fr-dispatch-stall-when-waiting-for-all-to-be-quiet
  Count dispatch stalls when waiting for all to be quiet.
k8-fr-dispatch-stall-when-waiting-far-xfer-or-resync-branch-pending
  Count dispatch stalls when a far control transfer or a resync branch is pending.
k8-fr-fpu-exceptions [,mask= qualifier]
  Count FPU exceptions. This event is supported in revision B and later CPUs. This event may be further qualified using qualifier, which is a +’ separated set of the following keywords:

sse-and-x87-microtraps
  Count SSE and x87 microtraps.
sse-reclass-microfaults
  Count SSE reclass microfaults
sse-retype-microfaults
  Count SSE retype microfaults
x87-reclass-microfaults
  Count x87 reclass microfaults.

The default is to count all types of exceptions.
k8-fr-interrupts-masked-cycles
  Count cycles when interrupts were masked (by CPU RFLAGS field IF was zero).
k8-fr-interrupts-masked-while-pending-cycles
  Count cycles while interrupts were masked while pending (i.e., cycles when INTR was asserted while CPU RFLAGS field IF was zero).
k8-fr-number-of-breakpoints-for-dr0
  Count the number of breakpoints for DR0.
k8-fr-number-of-breakpoints-for-dr1
  Count the number of breakpoints for DR1.
k8-fr-number-of-breakpoints-for-dr2
  Count the number of breakpoints for DR2.
k8-fr-number-of-breakpoints-for-dr3
  Count the number of breakpoints for DR3.
k8-fr-retired-branches
  Count retired branches including exceptions and interrupts.
k8-fr-retired-branches-mispredicted
  Count mispredicted retired branches.
k8-fr-retired-far-control-transfers
  Count retired far control transfers (which are always mispredicted).
k8-fr-retired-fastpath-double-op-instructions [,mask= qualifier]
  Count retired fastpath double op instructions. This event is supported in revision B and later CPUs. This event may be further qualified using qualifier, which is a +’ separated set of the following keywords:

low-op-pos-0
  Count instructions with the low op in position 0.
low-op-pos-1
  Count instructions with the low op in position 1.
low-op-pos-2
  Count instructions with the low op in position 2.

The default is to count all types of instructions.
k8-fr-retired-fpu-instructions [,mask= qualifier]
  Count retired FPU instructions. This event is supported in revision B and later CPUs. This event may be further qualified using qualifier, which is a +’ separated set of the following keywords:

mmx-3dnow
  Count MMX and 3DNow! instructions.
packed-sse-sse2
  Count packed SSE and SSE2 instructions.
scalar-sse-sse2
  Count scalar SSE and SSE2 instructions
x87 Count x87 instructions.

The default is to count all types of instructions.
k8-fr-retired-near-returns
  Count retired near returns.
k8-fr-retired-near-returns-mispredicted
  Count mispredicted near returns.
k8-fr-retired-resyncs
  Count retired resyncs (non-control transfer branches).
k8-fr-retired-taken-hardware-interrupts
  Count retired taken hardware interrupts.
k8-fr-retired-taken-branches
  Count retired taken branches.
k8-fr-retired-taken-branches-mispredicted
  Count retired taken branches that were mispredicted.
k8-fr-retired-taken-branches-mispredicted-by-addr-miscompare
  Count retired taken branches that were mispredicted only due to an address miscompare.
k8-fr-retired-uops
  Count retired uops.
k8-fr-retired-x86-instructions
  Count retired x86 instructions including exceptions and interrupts.
k8-ic-fetch
  Count instruction cache fetches.
k8-ic-instruction-fetch-stall
  Count cycles in stalls due to instruction fetch.
k8-ic-l1-itlb-miss-and-l2-itlb-hit
  Count L1 ITLB misses that are L2 ITLB hits.
k8-ic-l1-itlb-miss-and-l2-itlb-miss
  Count ITLB misses that miss in both L1 and L2 ITLBs.
k8-ic-microarchitectural-resync-by-snoop
  Count microarchitectural resyncs caused by snoops.
k8-ic-miss
  Count instruction cache misses.
k8-ic-refill-from-l2
  Count instruction cache refills from L2 cache.
k8-ic-refill-from-system
  Count instruction cache refills from system memory.
k8-ic-return-stack-hits
  Count hits to the return stack.
k8-ic-return-stack-overflow
  Count overflows of the return stack.
k8-ls-buffer2-full
  Count load/store buffer2 full events.
k8-ls-locked-operation [,mask= qualifier]
  Count locked operations. For revision C and later CPUs, the following qualifiers are supported:

cycles-in-request
  Count the number of cycles in the lock request/grant stage.
cycles-to-complete
  Count the number of cycles a lock takes to complete once it is non-speculative and is the older load/store operation.
locked-instructions
  Count the number of lock instructions executed.

The default is to count the number of lock instructions executed.
k8-ls-microarchitectural-late-cancel
  Count microarchitectural late cancels of operations in the load/store unit.
k8-ls-microarchitectural-resync-by-self-modifying-code
  Count microarchitectural resyncs caused by self-modifying code.
k8-ls-microarchitectural-resync-by-snoop
  Count microarchitectural resyncs caused by snoops.
k8-ls-retired-cflush-instructions
  Count retired CFLUSH instructions.
k8-ls-retired-cpuid-instructions
  Count retired CPUID instructions.
k8-ls-segment-register-load [,mask= qualifier]
  Count segment register loads. This event may be further qualified using qualifier, which is a +’ separated set of the following keywords:
cs Count CS register loads.
ds Count DS register loads.
es Count ES register loads.
fs Count FS register loads.
gs Count GS register loads.
ss Count SS register loads.

The default is to count all types of loads.
k8-nb-memory-controller-bypass-saturation [,mask= qualifier]
  Count memory controller bypass counter saturation events. This event may be further qualified using qualifier, which is a +’ separated set of the following keywords:

dram-controller-interface-bypass
  Count DRAM controller interface bypass.
dram-controller-queue-bypass
  Count DRAM controller queue bypass.
memory-controller-hi-pri-bypass
  Count memory controller high priority bypasses.
memory-controller-lo-pri-bypass
  Count memory controller low priority bypasses.

k8-nb-memory-controller-dram-slots-missed
  Count memory controller DRAM command slots missed (in MemClks).
k8-nb-memory-controller-page-access-event [,mask= qualifier]
  Count memory controller page access events. This event may be further qualified using qualifier, which is a +’ separated set of the following keywords:

page-conflict
  Count page conflicts.
page-hit
  Count page hits.
page-miss
  Count page misses.

The default is to count all types of events.
k8-nb-memory-controller-page-table-overflow
  Count memory control page table overflow events.
k8-nb-probe-result [,mask= qualifier]
  Count probe events. This event may be further qualified using qualifier, which is a +’ separated set of the following keywords:

probe-hit
  Count all probe hits.
probe-hit-dirty-no-memory-cancel
  Count probe hits without memory cancels.
probe-hit-dirty-with-memory-cancel
  Count probe hits with memory cancels.
probe-miss
  Count probe misses.
k8-nb-sized-commands [,mask= qualifier]
  Count sized commands issued. This event may be further qualified using qualifier, which is a +’ separated set of the following keywords:

nonpostwrszbyte
nonpostwrszdword
postwrszbyte
postwrszdword
rdszbyte
rdszdword
rdmodwr
 

The default is to count all types of commands.
k8-nb-memory-controller-turnaround [,mask= qualifier]
  Count memory control turnaround events. This event may be further qualified using qualifier, which is a +’ separated set of the following keywords:

dimm-turnaround
  Count DIMM turnarounds.
read-to-write-turnaround
  Count read to write turnarounds.
write-to-read-turnaround
  Count write to read turnarounds.

The default is to count all types of events.
k8-nb-ht-bus0-bandwidth [,mask= qualifier]
k8-nb-ht-bus1-bandwidth [,mask= qualifier]
k8-nb-ht-bus2-bandwidth [,mask= qualifier]
  Count events on the HyperTransport(tm) buses. These events may be further qualified using qualifier, which is a +’ separated set of the following keywords:

buffer-release
  Count buffer release messages sent.
command
  Count command messages sent.
data Count data messages sent.
nop Count nop messages sent.

The default is to count all types of messages.

    Intel P6 PMCS

Intel P6 PMCs are present in Intel Pentium Pro, Pentium II, Celeron, Pentium III and Pentium M processors.

These CPUs have two counters. Some events may only be used on specific counters and some events are defined only on specific processor models.

These PMCs are documented in
.Rs Volume 3: System Programming Guide
.Re

Some of these events are affected by processor errata described in
.Rs
.Re

Event specifiers for Intel P6 PMCs can have the following common qualifiers:
cmask= value
  Configure the PMC to increment only if the number of configured events measured in a cycle is greater than or equal to value.
edge Configure the PMC to count the number of deasserted to asserted transitions of the conditions expressed by the other qualifiers. If specified, the counter will increment only once whenever a condition becomes true, irrespective of the number of clocks during which the condition remains true.
inv Invert the sense of comparision when the "cmask" qualifier is present, making the counter increment when the number of events per cycle is less than the value specified by the "cmask" qualifier.
os Configure the PMC to count events happening at processor privilege level 0.
umask= value
  This qualifier is used to further qualify the event selected (see below).
usr Configure the PMC to count events occurring at privilege levels 1, 2 or 3.

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

The event specifiers supported by Intel P6 PMCs are:
p6-baclears
  Count the number of times a static branch prediction was made by the branch decoder because the BTB did not have a prediction.
p6-br-bac-missp-exec
  (Pentium M) Count the number of branch instructions executed that where mispredicted at the Front End (BAC).
p6-br-bogus
  Count the number of bogus branches.
p6-br-call-exec
  (Pentium M) Count the number of call instructions executed.
p6-br-call-missp-exec
  (Pentium M) Count the number of call instructions executed that were mispredicted.
p6-br-cnd-exec
  (Pentium M) Count the number of conditional branch instructions executed.
p6-br-cnd-missp-exec
  (Pentium M) Count the number of conditional branch instructions executed that were mispredicted.
p6-br-ind-call-exec
  (Pentium M) Count the number of indirect call instructions executed.
p6-br-ind-exec
  (Pentium M) Count the number of indirect branch instructions executed.
p6-br-ind-missp-exec
  (Pentium M) Count the number of indirect branch instructions executed that were mispredicted.
p6-br-inst-decoded
  Count the number of branch instructions decoded.
p6-br-inst-exec
  (Pentium M) Count the number of branch instructions executed but necessarily retired.
p6-br-inst-retired
  Count the number of branch instructions retired.
p6-br-miss-pred-retired
  Count the number of mispredicted branch instructions retired.
p6-br-miss-pred-taken-ret
  Count the number of taken mispredicted branches retired.
p6-br-missp-exec
  (Pentium M) Count the number of branch instructions executed that were mispredicted at execution.
p6-br-ret-bac-missp-exec
  (Pentium M) Count the number of return instructions executed that were mispredicted at the Front End (BAC).
p6-br-ret-exec
  (Pentium M) Count the number of return instructions executed.
p6-br-ret-missp-exec
  (Pentium M) Count the number of return instructions executed that were mispredicted at execution.
p6-br-taken-retired
  Count the number of taken branches retired.
p6-btb-misses
  Count the number of branches for which the BTB did not produce a prediction.
p6-bus-bnr-drv
  Count the number of bus clock cycles during which this processor is driving the BNR# pin.
p6-bus-data-rcv
  Count the number of bus clock cycles during which this processor is receiving data.
p6-bus-drdy-clocks [,umask= qualifier]
  Count the number of clocks during which DRDY# is asserted. An additional qualifier may be specified, and comprises one of the following keywords:

any Count transactions generated by any agent on the bus.
self Count transactions generated by this processor.

The default is to count operations generated by this processor.
p6-bus-hit-drv
  Count the number of bus clock cycles during which this processor is driving the HIT# pin.
p6-bus-hitm-drv
  Count the number of bus clock cycles during which this processor is driving the HITM# pin.
p6-bus-lock-clocks [,umask= qualifier]
  Count the number of clocks during with LOCK# is asserted on the external system bus. An additional qualifier may be specified and comprises one of the following keywords:

any Count transactions generated by any agent on the bus.
self Count transactions generated by this processor.

The default is to count operations generated by this processor.
p6-bus-req-outstanding
  Count the number of bus requests outstanding in any given cycle.
p6-bus-snoop-stall
  Count the number of clock cycles during which the bus is snoop stalled.
p6-bus-tran-any [,umask= qualifier]
  Count the number of completed bus transactions of any kind. An additional qualifier may be specified and comprises one of the following keywords:

any Count transactions generated by any agent on the bus.
self Count transactions generated by this processor.

The default is to count operations generated by this processor.
p6-bus-tran-brd [,umask= qualifier]
  Count the number of burst read transactions. An additional qualifier may be specified and comprises one of the following keywords:

any Count transactions generated by any agent on the bus.
self Count transactions generated by this processor.

The default is to count operations generated by this processor.
p6-bus-tran-burst [,umask= qualifier]
  Count the number of completed burst transactions. An additional qualifier may be specified and comprises one of the following keywords:

any Count transactions generated by any agent on the bus.
self Count transactions generated by this processor.

The default is to count operations generated by this processor.
p6-bus-tran-def [,umask= qualifier]
  Count the number of completed deferred transactions. An additional qualifier may be specified and comprises one of the following keywords:

any Count transactions generated by any agent on the bus.
self Count transactions generated by this processor.

The default is to count operations generated by this processor.
p6-bus-tran-ifetch [,umask= qualifier]
  Count the number of completed instruction fetch transactions. An additional qualifier may be specified and comprises one of the following keywords:

any Count transactions generated by any agent on the bus.
self Count transactions generated by this processor.

The default is to count operations generated by this processor.
p6-bus-tran-inval [,umask= qualifier]
  Count the number of completed invalidate transactions. An additional qualifier may be specified and comprises one of the following keywords:

any Count transactions generated by any agent on the bus.
self Count transactions generated by this processor.

The default is to count operations generated by this processor.
p6-bus-tran-mem [,umask= qualifier]
  Count the number of completed memory transactions. An additional qualifier may be specified and comprises one of the following keywords:

any Count transactions generated by any agent on the bus.
self Count transactions generated by this processor.

The default is to count operations generated by this processor.
p6-bus-tran-pwr [,umask= qualifier]
  Count the number of completed partial write transactions. An additional qualifier may be specified and comprises one of the following keywords:

any Count transactions generated by any agent on the bus.
self Count transactions generated by this processor.

The default is to count operations generated by this processor.
p6-bus-tran-rfo [,umask= qualifier]
  Count the number of completed read-for-ownership transactions. An additional qualifier may be specified and comprises one of the following keywords:

any Count transactions generated by any agent on the bus.
self Count transactions generated by this processor.

The default is to count operations generated by this processor.
p6-bus-trans-io [,umask= qualifier]
  Count the number of completed I/O transactions. An additional qualifier may be specified and comprises one of the following keywords:

any Count transactions generated by any agent on the bus.
self Count transactions generated by this processor.

The default is to count operations generated by this processor.
p6-bus-trans-p [,umask= qualifier]
  Count the number of completed partial transactions. An additional qualifier may be specified and comprises one of the following keywords:

any Count transactions generated by any agent on the bus.
self Count transactions generated by this processor.

The default is to count operations generated by this processor.
p6-bus-trans-wb [,umask= qualifier]
  Count the number of completed write-back transactions. An additional qualifier may be specified and comprises one of the following keywords:

any Count transactions generated by any agent on the bus.
self Count transactions generated by this processor.

The default is to count operations generated by this processor.
p6-cpu-clk-unhalted
  Count the number of cycles during with the processor was not halted.

(Pentium M) Count the number of cycles during with the processor was not halted and not in a thermal trip.

p6-cycles-div-busy
  Count the number of cycles during which the divider is busy and cannot accept new divides. This event is only allocated on counter 0.
p6-cycles-in-pending-and-masked
  Count the number of processor cycles for which interrupts were disabled and interrupts were pending.
p6-cycles-int-masked
  Count the number of processor cycles for which interrupts were disabled.
p6-data-mem-refs
  Count all loads and all stores using any memory type, including internal retries. Each part of a split store is counted separately.
p6-dcu-lines-in
  Count the total lines allocated in the data cache unit.
p6-dcu-m-lines-in
  Count the number of M state lines allocated in the data cache unit.
p6-dcu-m-lines-out
  Count the number of M state lines evicted from the data cache unit.
p6-dcu-miss-outstanding
  Count the weighted number of cycles while a data cache unit miss is outstanding, incremented by the number of outstanding cache misses at any time.
p6-div
  Count the number of floating point multiplies. This event is only allocated on counter 1.
p6-emon-esp-uops
  (Pentium M) Count the total number of micro-ops.
p6-emon-est-trans [,umask= qualifier]
  (Pentium M) Count the number of Enhanced Intel SpeedStep transitions. An additional qualifier may be specified, and can be one of the following keywords:

all Count all transitions.
freq Count only frequency transitions.

The default is to count all transitions.
p6-emon-fused-uops-ret [,umask= qualifier]
  (Pentium M) Count the number of retired fused micro-ops. An additional qualifier may be specified, and may be one of the following keywords:

all Count all fused micro-ops.
loadop
  Count only load and op micro-ops.
stdsta
  Count only STD/STA micro-ops.

The default is to count all fused micro-ops.
p6-emon-kni-comp-inst-ret
  (Pentium III) Count the number of SSE computational instructions retired. An additional qualifier may be specified, and comprises one of the following keywords:

packed-and-scalar
  Count packed and scalar operations.
scalar
  Count scalar operations only.

The default is to count packed and scalar operations.
p6-emon-kni-inst-retired [,umask= qualifier]
  (Pentium III) Count the number of SSE instructions retired. An additional qualifier may be specified, and comprises one of the following keywords:

packed-and-scalar
  Count packed and scalar operations.
scalar
  Count scalar operations only.

The default is to count packed and scalar operations.
p6-emon-kni-pref-dispatched [,umask= qualifier]
  (Pentium III) Count the number of SSE prefetch or weakly ordered instructions dispatched (including speculative prefetches). An additional qualifier may be specified, and comprises one of the following keywords:

nta Count non-temporal prefetches.
t1 Count prefetches to L1.
t2 Count prefetches to L2.
wos Count weakly ordered stores.

The default is to count non-temporal prefetches.
p6-emon-kni-pref-miss [,umask= qualifier]
  (Pentium III) Count the number of prefetch or weakly ordered instructions that miss all caches. An additional qualifier may be specified, and comprises one of the following keywords:

nta Count non-temporal prefetches.
t1 Count prefetches to L1.
t2 Count prefetches to L2.
wos Count weakly ordered stores.

The default is to count non-temporal prefetches.
p6-emon-pref-rqsts-dn
  (Pentium M) Count the number of downward prefetches issued.
p6-emon-pref-rqsts-up
  (Pentium M) Count the number of upward prefetches issued.
p6-emon-simd-instr-retired
  (Pentium M) Count the number of retired MMX instructions.
p6-emon-sse-sse2-comp-inst-retired [,umask= qualifier]
  (Pentium M) Count the number of computational SSE instructions retired. An additional qualifier may be specified and can be one of the following keywords:

sse-packed-single
  Count SSE packed-single instructions.
sse-scalar-single
  Count SSE scalar-single instructions.
sse2-packed-double
  Count SSE2 packed-double instructions.
sse2-scalar-double
  Count SSE2 scalar-double instructions.

The default is to count SSE packed-single instructions.
p6-emon-sse-sse2-inst-retired [,umask= qualifer]
 

(Pentium M) Count the number of SSE instructions retired. An additional qualifier can be specified, and can be one of the following keywords:

sse-packed-single
  Count SSE packed-single instructions.
sse-packed-single-scalar-single
  Count SSE packed-single and scalar-single instructions.
sse2-packed-double
  Count SSE2 packed-double instructions.
sse2-scalar-double
  Count SSE2 scalar-double instructions.

The default is to count SSE packed-single instructions.
p6-emon-synch-uops
  (Pentium M) Count the number of sync micro-ops.
p6-emon-thermal-trip
  (Pentium M) Count the duration or occurrences of thermal trips. Use the "edge" qualifier to count occurrences of thermal trips.
p6-emon-unfusion
  (Pentium M) Count the number of unfusion events in the reorder buffer.
p6-flops
  Count the number of computational floating point operations retired. This event is only allocated on counter 0.
p6-fp-assist
  Count the number of floating point exceptions handled by microcode. This event is only allocated on counter 1.
p6-fp-comps-ops-exe
  Count the number of computation floating point operations executed. This event is only allocated on counter 0.
p6-fp-mmx-trans [,umask= qualifier]
  (Pentium II, Pentium III) Count the number of transitions between MMX and floating-point instructions. An additional qualifier may be specified, and comprises one of the following keywords:

mmxtofp
  Count transitions from MMX instructions to floating-point instructions.
fptommx
  Count transitions from floating-point instructions to MMX instructions.

The default is to count MMX to floating-point transitions.
p6-hw-int-rx
  Count the number of hardware interrupts received.
p6-ifu-fetch
  Count the number of instruction fetches, both cacheable and non-cacheable.
p6-ifu-fetch-miss
  Count the number of instruction fetch misses (i.e., those that produce memory accesses).
p6-ifu-mem-stall
  Count the number of cycles instruction fetch is stalled for any reason.
p6-ild-stall
  Count the number of cycles the instruction length decoder is stalled.
p6-inst-decoded
  Count the number of instructions decoded.
p6-inst-retired
  Count the number of instructions retired.
p6-itlb-miss
  Count the number of instruction TLB misses.
p6-l2-ads
  Count the number of L2 address strobes.
p6-l2-dbus-busy
  Count the number of cycles during which the L2 cache data bus was busy.
p6-l2-dbus-busy-rd
  Count the number of cycles during which the L2 cache data bus was busy transferring read data from L2 to the processor.
p6-l2-ifetch [,umask= qualifier]
  Count the number of L2 instruction fetches. An additional qualifier may be specified and comprises a list of the following keywords separated by +’ characters:

e Count operations affecting E (exclusive) state lines.
i Count operations affecting I (invalid) state lines.
m Count operations affecting M (modified) state lines.
s Count operations affecting S (shared) state lines.

The default is to count operations affecting all (MESI) state lines.
p6-l2-ld [,umask= qualifier]
  Count the number of L2 data loads. An additional qualifier may be specified and comprises a list of the following keywords separated by +’ characters:

both (Pentium M) Count both hardware-prefetched lines and non-hardware-prefetched lines.
e Count operations affecting E (exclusive) state lines.
hw (Pentium M) Count hardware-prefetched lines only.
i Count operations affecting I (invalid) state lines.
m Count operations affecting M (modified) state lines.
nonhw (Pentium M) Exclude hardware-prefetched lines.
s Count operations affecting S (shared) state lines.

The default on processors other than Pentium M processors is to count operations affecting all (MESI) state lines. The default on Pentium M processors is to count both hardware-prefetched and non-hardware-prefetch operations on all (MESI) state lines. (Errata) This event is affected by processor errata E53.
p6-l2-lines-in [,umask= qualifier]
  Count the number of L2 lines allocated. An additional qualifier may be specified and comprises a list of the following keywords separated by +’ characters:

both (Pentium M) Count both hardware-prefetched lines and non-hardware-prefetched lines.
e Count operations affecting E (exclusive) state lines.
hw (Pentium M) Count hardware-prefetched lines only.
i Count operations affecting I (invalid) state lines.
m Count operations affecting M (modified) state lines.
nonhw (Pentium M) Exclude hardware-prefetched lines.
s Count operations affecting S (shared) state lines.

The default on processors other than Pentium M processors is to count operations affecting all (MESI) state lines. The default on Pentium M processors is to count both hardware-prefetched and non-hardware-prefetch operations on all (MESI) state lines. (Errata) This event is affected by processor errata E45.
p6-l2-lines-out [,umask= qualifier]
  Count the number of L2 lines evicted. An additional qualifier may be specified and comprises a list of the following keywords separated by +’ characters:

both (Pentium M) Count both hardware-prefetched lines and non-hardware-prefetched lines.
e Count operations affecting E (exclusive) state lines.
hw (Pentium M) Count hardware-prefetched lines only.
i Count operations affecting I (invalid) state lines.
m Count operations affecting M (modified) state lines.
nonhw (Pentium M only) Exclude hardware-prefetched lines.
s Count operations affecting S (shared) state lines.

The default on processors other than Pentium M processors is to count operations affecting all (MESI) state lines. The default on Pentium M processors is to count both hardware-prefetched and non-hardware-prefetch operations on all (MESI) state lines. (Errata) This event is affected by processor errata E45.
p6-l2-m-lines-inm
  Count the number of modified lines allocated in L2 cache.
p6-l2-m-lines-outm [,umask= qualifier]
  Count the number of L2 M-state lines evicted.

(Pentium M) On these processors an additional qualifier may be specified and comprises a list of the following keywords separated by +’ characters:

both Count both hardware-prefetched lines and non-hardware-prefetched lines.
hw Count hardware-prefetched lines only.
nonhw Exclude hardware-prefetched lines.

The default is to count both hardware-prefetched and non-hardware-prefetch operations. (Errata) This event is affected by processor errata E53.
p6-l2-rqsts [,umask= qualifier]
  Count the total number of L2 requests. An additional qualifier may be specified and comprises a list of the following keywords separated by +’ characters:

e Count operations affecting E (exclusive) state lines.
i Count operations affecting I (invalid) state lines.
m Count operations affecting M (modified) state lines.
s Count operations affecting S (shared) state lines.

The default is to count operations affecting all (MESI) state lines.
p6-l2-st
  Count the number of L2 data stores. An additional qualifier may be specified and comprises a list of the following keywords separated by +’ characters:

e Count operations affecting E (exclusive) state lines.
i Count operations affecting I (invalid) state lines.
m Count operations affecting M (modified) state lines.
s Count operations affecting S (shared) state lines.

The default is to count operations affecting all (MESI) state lines.
p6-ld-blocks
  Count the number of load operations delayed due to store buffer blocks.
p6-misalign-mem-ref
  Count the number of misaligned data memory references (crossing a 64 bit boundary).
p6-mmx-assist
  (Pentium II, Pentium III) Count the number of MMX assists executed.
p6-mmx-instr-exec
  (Celeron, Pentium II) Count the number of MMX instructions executed, except MOVQ and MOVD stores from register to memory.
p6-mmx-instr-ret
  (Pentium II) Count the number of MMX instructions retired.
p6-mmx-instr-type-exec [,umask= qualifier]
  (Pentium II, Pentium III) Count the number of MMX instructions executed. An additional qualifier may be specified and comprises a list of the following keywords separated by +’ characters:

pack Count MMX pack operation instructions.
packed-arithmetic
  Count MMX packed arithmetic instructions.
packed-logical
  Count MMX packed logical instructions.
packed-multiply
  Count MMX packed multiply instructions.
packed-shift
  Count MMX packed shift instructions.
unpack
  Count MMX unpack operation instructions.

The default is to count all operations.
p6-mmx-sat-instr-exec
  (Pentium II, Pentium III) Count the number of MMX saturating instructions executed.
p6-mmx-uops-exec
  (Pentium II, Pentium III) Count the number of MMX micro-ops executed.
p6-mul
  Count the number of floating point multiplies. This event is only allocated on counter 1.
p6-partial-rat-stalls
  Count the number of cycles or events for partial stalls.
p6-resource-stalls
  Count the number of cycles there was a resource related stall of any kind.
p6-ret-seg-renames
  (Pentium II, Pentium III) Count the number of segment register rename events retired.
p6-sb-drains
  Count the number of cycles the store buffer is draining.
p6-seg-reg-renames [,umask= qualifier]
  (Pentium II, Pentium III) Count the number of segment register renames. An additional qualifier may be specified, and comprises a list of the following keywords separated by +’ characters:

ds Count renames for segment register DS.
es Count renames for segment register ES.
fs Count renames for segment register FS.
gs Count renames for segment register GS.

The default is to count operations affecting all segment registers.
p6-seg-rename-stalls
  (Pentium II, Pentium III) Count the number of segment register renaming stalls. An additional qualifier may be specified, and comprises a list of the following keywords separated by +’ characters:

ds Count stalls for segment register DS.
es Count stalls for segment register ES.
fs Count stalls for segment register FS.
gs Count stalls for segment register GS.

The default is to count operations affecting all the segment registers.
p6-segment-reg-loads
  Count the number of segment register loads.
p6-uops-retired
  Count the number of micro-ops retired.

    Intel P4 PMCS

Intel P4 PMCs are present in Intel Pentium 4 and Xeon processors. These PMCs are documented in
.Rs Volume 3: System Programming Guide
.Re Further information about using these PMCs may be found in
.Rs
.Re Some of these events are affected by processor errata described in
.Rs
.Re

Event specifiers for Intel P4 PMCs can have the following common qualifiers:
active= choice
  (On P4 HTT CPUs) Filter event counting based on which logical processors are active. The allowed values of choice are:

any Count when either logical processor is active.
both Count when both logical processors are active.
none Count only when neither logical processor is active.
single
  Count only when one logical processor is active.

The default is "both".
cascade
  Configure the PMC to cascade onto its partner. See Cascading P4 PMCs below for more information.
edge Configure the counter to count false to true transitions of the threshold comparision output. This qualifier only takes effect if a threshold qualifier has also been specified.
complement
  Configure the counter to increment only when the event count seen is less than the threshold qualifier value specified.
mask= qualifier
  Many event specifiers for Intel P4 PMCs need to be additionally qualified using a mask qualifier. The allowed syntax for these qualifiers is event specific and is described along with the events.
os Configure the PMC to count when the CPL of the processor is 0.
precise
  Select precise event based sampling. Precise sampling is supported by the hardware for a limited set of events.
tag= value
  Configure the PMC to tag the internal uop selected by the other fields in this event specifier with value value. This feature is used when cascading PMCs.
threshold= value
  Configure the PMC to increment only when the event counts seen are greater than the specified threshold value value.
usr Configure the PMC to count when the CPL of the processor is 1, 2 or 3.

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

On Intel Pentium 4 processors with HTT, events are divided into two classes:

TS Events
  are those where hardware can differentiate between events generated on one logical processor from those generated on the other.
TI Events
  are those where hardware cannot differentiate between events generated by multiple logical processors in a package.

Only TS events are allowed for use with process-mode PMCs on Pentium-4/HTT CPUs.

The event specifiers supported by Intel P4 PMCs are:

p4-128bit-mmx-uop [,mask= flags]
  (TI event) Count integer SIMD SSE2 instructions that operate on 128 bit SIMD operands. Qualifier flags can take the following value (which is also the default):

all Count all uops operating on 128 bit SIMD integer operands in memory or XMM register.

If an instruction contains more than one 128 bit MMX uop, then each uop will be counted.
p4-64bit-mmx-uop [,mask= flags]
  (TI event) Count MMX instructions that operate on 64 bit SIMD operands. Qualifier flags can take the following value (which is also the default):

all Count all uops operating on 64 bit SIMD integer operands in memory or in MMX registers.

If an instruction contains more than one 64 bit MMX uop, then each uop will be counted.
p4-b2b-cycles
  (TI event) Count back-to-back bys cycles. Further documentation for this event is unavailable.
p4-bnr
  (TI event) Count bus-not-ready conditions. Further documentation for this event is unavailable.
p4-bpu-fetch-request [,mask= qualifier]
  (TS event) Count instruction fetch requests qualified by additional flags specified in qualifier. At this point only one flag is supported:

tcmiss
  Count trace cache lookup misses.

The default qualifier is also "mask=tcmiss".
p4-branch-retired [,mask= flags]
  (TS event) Counts retired branches. Qualifier flags is a list of the following +’ separated strings:

mmnp Count branches not-taken and predicted.
mmnm Count branches not-taken and mis-predicted.
mmtp Count branches taken and predicted.
mmtm Count branches taken and mis-predicted.

The default qualifier counts all four kinds of branches.
p4-bsq-active-entries [,mask= qualifier]
  (TS event) Count the number of entries (clipped at 15) currently active in the BSQ. Qualifier qualifier is a +’ separated set of the following flags:

req-type0, req-type1
  Forms a 2-bit number used to select the request type encoding:

0 reads excluding read invalidate
1 read invalidates
2 writes other than writebacks
3 writebacks

Bit "req-type1" is the MSB for this two bit number.
req-len0, req-len1
  Forms a two-bit number that specifies the request length encoding:

0 0 chunks
1 1 chunk
3 8 chunks

Bit "req-len1" is the MSB for this two bit number.
req-io-type
  Count requests that are input or output requests.
req-lock-type
  Count requests that lock the bus.
req-lock-cache
  Count requests that lock the cache.
req-split-type
  Count requests that is a bus 8-byte chunk that is split across an 8-byte boundary.
req-dem-type
  Count requests that are demand (not prefetches) if set. Count requests that are prefetches if not set.
req-ord-type
  Count requests that are ordered.
mem-type0, mem-type1, mem-type2
  Forms a 3-bit number that specifies a memory type encoding:

0 UC
1 USWC
4 WT
5 WP
6 WB

Bit "mem-type2" is the MSB of this 3-bit number.

The default qualifier has all the above bits set.

Edge triggering using the "edge" qualifier should not be used with this event when counting cycles.
p4-bsq-allocation [,mask= qualifier]
  (TS event) Count allocations in the bus sequence unit according to the flags specified in qualifier, which is a +’ separated set of the following flags:

req-type0, req-type1
  Forms a 2-bit number used to select the request type encoding:

0 reads excluding read invalidate
1 read invalidates
2 writes other than writebacks
3 writebacks

Bit "req-type1" is the MSB for this two bit number.
req-len0, req-len1
  Forms a two-bit number that specifies the request length encoding:

0 0 chunks
1 1 chunk
3 8 chunks

Bit "req-len1" is the MSB for this two bit number.
req-io-type
  Count requests that are input or output requests.
req-lock-type
  Count requests that lock the bus.
req-lock-cache
  Count requests that lock the cache.
req-split-type
  Count requests that is a bus 8-byte chunk that is split across an 8-byte boundary.
req-dem-type
  Count requests that are demand (not prefetches) if set. Count requests that are prefetches if not set.
req-ord-type
  Count requests that are ordered.
mem-type0, mem-type1, mem-type2
  Forms a 3-bit number that specifies a memory type encoding:

0 UC
1 USWC
4 WT
5 WP
6 WB

Bit "mem-type2" is the MSB of this 3-bit number.

The default qualifier has all the above bits set.

This event is usually used along with the "edge" qualifier to avoid multiple counting.
p4-bsq-cache-reference [,mask= qualifier]
  (TS event) Count cache references as seen by the bus unit (2nd or 3rd level cache references). Qualifier qualifier is a +’ separated list of the following keywords:

rd-2ndl-hits
  Count 2nd level cache hits in the shared state.
rd-2ndl-hite
  Count 2nd level cache hits in the exclusive state.
rd-2ndl-hitm
  Count 2nd level cache hits in the modified state.
rd-3rdl-hits
  Count 3rd level cache hits in the shared state.
rd-3rdl-hite
  Count 3rd level cache hits in the exclusive state.
rd-3rdl-hitm
  Count 3rd level cache hits in the modified state.
rd-2ndl-miss
  Count 2nd level cache misses.
rd-3rdl-miss
  Count 3rd level cache misses.
wr-2ndl-miss
  Count write-back lookups from the data access cache that miss the 2nd level cache.

The default is to count all the above events.
p4-execution-event [,mask= flags]
  (TS event) Count the retirement of tagged uops selected through the execution tagging mechanism. Qualifier flags can contain the following strings separated by +’ characters:

nbogus0, nbogus1, nbogus2, nbogus3
  The marked uops are not bogus.
bogus0, bogus1, bogus2, bogus3
  The marked uops are bogus.

This event requires additional (upstream) events to be allocated to perform the desired uop tagging. The default is to set all the above flags. This event can be used for precise event based sampling.
p4-front-end-event [,mask= flags]
  (TS event) Count the retirement of tagged uops selected through the front-end tagging mechanism. Qualifier flags can contain the following strings separated by +’ characters:

nbogus
  The marked uops are not bogus.
bogus The marked uops are bogus.

This event requires additional (upstream) events to be allocated to perform the desired uop tagging. The default is to select both kinds of events. This event can be used for precise event based sampling.
p4-fsb-data-activity [,mask= flags]
  (TI event) Count each DBSY or DRDY event selected by qualifier flags. Qualifier flags is a +’ separated set of the following flags:

drdy-drv
  Count when this processor is driving data onto the bus.
drdy-own
  Count when this processor is reading data from the bus.
drdy-other
  Count when data is on the bus but not being sampled by this processor.
dbsy-drv
  Count when this processor reserves the bus for use in the next cycle in order to drive data.
dbsy-own
  Count when some agent reserves the bus for use in the next bus cycle to drive data that this processor will sample.
dbsy-other
  Count when some agent reserves the bus for use in the next bus cycle to drive data that this processor will not sample.

Flags "drdy-own" and "drdy-other" are mutually exclusive. Flags "dbsy-own" and "dbsy-other" are mutually exclusive. The default value for qualifier is "drdy-drv+drdy-own+dbsy-drv+dbsy-own".
p4-global-power-events [,mask= flags]
  (TS event) Count cycles during which the processor is not stopped. Qualifier flags can take the following value (which is also the default):

running
  Count cycles when the processor is active.

p4-instr-retired [,mask= flags]
  (TS event) Count instructions retired during a clock cycle. Qualifer flags comprises of the following strings separated by +’ characters:

nbogusntag
  Count non-bogus instructions that are not tagged.
nbogustag
  Count non-bogus instructions that are tagged.
bogusntag
  Count bogus instructions that are not tagged.
bogustag
  Count bogus instructions that are tagged.

The default qualifier counts all the above kinds of instructions.
p4-ioq-active-entries Xo
  [,mask= qualifier] [,busreqtype= req-type]
  (TS event) Count the number of entries (clipped at 15) in the IOQ that are active. The event masks are specified by qualifier qualifier and req-type.

Qualifier qualifier is a +’ separated set of the following flags:

all-read
  Count read entries.
all-write
  Count write entries.
mem-uc
  Count entries accessing uncacheable memory.
mem-wc
  Count entries accessing write-combining memory.
mem-wt
  Count entries accessing write-through memory.
mem-wp
  Count entries accessing write-protected memory
mem-wb
  Count entries accessing write-back memory.
own Count store requests driven by the processor (i.e., not by other processors or by DMA).
other Count store requests driven by other processors or by DMA.
prefetch
  Include hardware and software prefetch requests in the count.

The default value for qualifier is to enable all the above flags.

The req-type qualifier is a 5-bit number can be additionally used to select a specific bus request type. The default is 0.

The "edge" qualifier should not be used when counting cycles with this event. The exact behaviour of this event depends on the processor revision.
p4-ioq-allocation Xo
  [,mask= qualifier] [,busreqtype= req-type]
  (TS event) Count various types of transactions on the bus matching the flags set in qualifier and req-type.

Qualifier qualifier is a +’ separated set of the following flags:

all-read
  Count read entries.
all-write
  Count write entries.
mem-uc
  Count entries accessing uncacheable memory.
mem-wc
  Count entries accessing write-combining memory.
mem-wt
  Count entries accessing write-through memory.
mem-wp
  Count entries accessing write-protected memory
mem-wb
  Count entries accessing write-back memory.
own Count store requests driven by the processor (i.e., not by other processors or by DMA).
other Count store requests driven by other processors or by DMA.
prefetch
  Include hardware and software prefetch requests in the count.

The default value for qualifier is to enable all the above flags.

The req-type qualifier is a 5-bit number can be additionally used to select a specific bus request type. The default is 0.

The "edge" qualifier is normally used with this event to prevent multiple counting. The exact behaviour of this event depends on the processor revision.
p4-itlb-reference [mask= qualifier]
  (TS event) Count translations using the intruction translation look-aside buffer. The qualifier argument is a list of the following strings separated by +’ characters.

hit Count ITLB hits.
miss Count ITLB misses.
hit-uc
  Count uncacheable ITLB hits.

If no qualifier is specified the default is to count all the three kinds of ITLB translations.
p4-load-port-replay [,mask= qualifier]
  (TS event) Count replayed events at the load port. Qualifier qualifier can take on one value:

split-ld
  Count split loads.

The default value for qualifier is "split-ld".
p4-mispred-branch-retired [,mask= flags]
  (TS event) Count mispredicted IA-32 branch instructions. Qualifier flags can take the following value (which is also the default):

nbogus
  Count non-bogus retired branch instructions.
p4-machine-clear [,mask= flags]
  (TS event) Count the number of pipeline clears seen by the processor. Qualifer flags is a list of the following strings separated by +’ characters:

clear Count for a portion of the many cycles when the machine is being cleared for any reason.
moclear
  Count machine clears due to memory ordering issues.
smclear
  Count machine clears due to self-modifying code.

Use qualifier "edge" to get a count of occurrences of machine clears. The default qualifier is "clear".
p4-memory-cancel [,mask= event-list]
  (TS event) Count the cancelling of various kinds of requests in the data cache address control unit of the CPU. The qualifier event-list is a list of the following strings separated by +’ characters:

st-rb-full
  Requests cancelled because no store request buffer was available.
64k-conf
  Requests that conflict due to 64K aliasing.

If event-list is not specified, then the default is to count both kinds of events.
p4-memory-complete [,mask= event-list]
  (TS event) Count the completion of load split, store split, uncacheable split and uncacheable load operations selected by qualifier event-list. The qualifier event-list is a +’ separated list of the following flags:

lsc Count load splits completed, excluding loads from uncacheable or write-combining areas.
ssc Count any split stores completed.

The default is to count both kinds of operations.
p4-mob-load-replay [,mask= qualifier]
  (TS event) Count load replays triggered by the memory order buffer. Qualifier qualifier can be a +’ separated list of the following flags:

no-sta
  Count replays because of unknown store addresses.
no-std
  Count replays because of unknown store data.
partial-data
  Count replays because of partially overlapped data accesses between load and store operations.
unalgn-addr
  Count replays because of mismatches in the lower 4 bits of load and store operations.

The default qualifier is no-sta+no-std+partial-data+unalgn-addr.
p4-packed-dp-uop [,mask= flags]
  (TI event) Count packed double-precision uops. Qualifier flags can take the following value (which is also the default):

all Count all uops operating on packed double-precision operands.
p4-packed-sp-uop [,mask= flags]
  (TI event) Count packed single-precision uops. Qualifier flags can take the following value (which is also the default):

all Count all uops operating on packed single-precision operands.
p4-page-walk-type [,mask= qualifier]
  (TI event) Count page walks performed by the page miss handler. Qualifier qualifier can be a +’ separated list of the following keywords:

dtmiss
  Count page walks for data TLB misses.
itmiss
  Count page walks for instruction TLB misses.

The default value for qualifier is "dtmiss+itmiss".
p4-replay-event [,mask= flags]
  (TS event) Count the retirement of tagged uops selected through the replay tagging mechanism. Qualifier flags contains a +’ separated set of the following strings:

nbogus
  The marked uops are not bogus.
bogus The marked uops are bogus.

This event requires additional (upstream) events to be allocated to perform the desired uop tagging. The default qualifier counts both kinds of uops. This event can be used for precise event based sampling.
p4-resource-stall [,mask= flags]
  (TS event) Count the occurrence or latency of stalls in the allocator. Qualifier flags can take the following value (which is also the default):

sbfull
  A stall due to the lack of store buffers.
p4-response
  (TI event) Count different types of responses. Further documentation on this event is not available.
p4-retired-branch-type [,mask= flags]
  (TS event) Count branches retired. Qualifier flags contains a +’ separated list of strings:

conditional
  Count conditional jumps.
call Count direct and indirect call branches.
return
  Count return branches.
indirect
  Count returns, indirect calls or indirect jumps.

The default qualifier counts all the above branch types.
p4-retired-mispred-branch-type [,mask= flags]
  (TS event) Count mispredicted branches retired. Qualifier flags contains a +’ separated list of strings:

conditional
  Count conditional jumps.
call Count indirect call branches.
return
  Count return branches.
indirect
  Count returns, indirect calls or indirect jumps.

The default qualifier counts all the above branch types.
p4-scalar-dp-uop [,mask= flags]
  (TI event) Count the number of scalar double-precision uops. Qualifier flags can take the following value (which is also the default):

all Count the number of scalar double-precision uops.
p4-scalar-sp-uop [,mask= flags]
  (TI event) Count the number of scalar single-precision uops. Qualifier flags can take the following value (which is also the default):

all Count all uops operating on scalar single-precision operands.
p4-snoop
  (TI event) Count snoop traffic. Further documentation on this event is not available.
p4-sse-input-assist [,mask= flags]
  (TI event) Count the number of times an assist is required to handle problems with the operands for SSE and SSE2 operations. Qualifier flags can take the following value (which is also the default):

all Count assists for all SSE and SSE2 uops.
p4-store-port-replay [,mask= qualifier]
  (TS event) Count events replayed at the store port. Qualifier qualifier can take on one value:

split-st
  Count split stores.

The default value for qualifier is "split-st".
p4-tc-deliver-mode [,mask= qualifier]
  (TI event) Count the duration in cycles of operating modes of the trace cache and decode engine. The desired operating mode is selected by qualifier, which is a list of the following strings separated by +’ characters:

DD Both logical processors are in deliver mode.
DB Logical processor 0 is in deliver mode while logical processor 1 is in build mode.
DI Logical processor 0 is in deliver mode while logical processor 1 is halted, or in machine clear, or transitioning to a long microcode flow.
BD Logical processor 0 is in build mode while logical processor 1 is in deliver mode.
BB Both logical processors are in build mode.
BI Logical processor 0 is in build mode while logical processor 1 is halted, or in machine clear or transitioning to a long microcode flow.
ID Logical processor 0 is halted, or in machine clear or transitioning to a long microcode flow while logical processor 1 is in deliver mode.
IB Logical processor 0 is halted, or in machine clear or transitioning to a long microcode flow while logical processor 1 is in build mode.

If there is only one logical processor in the processor package then the qualifier for logical processor 1 is ignored. If no qualifier is specified, the default qualifier is "DD+DB+DI+BD+BB+BI+ID+IB".
p4-tc-ms-xfer [,mask= flags]
  (TI event) Count the number of times uop delivery changed from the trace cache to MS ROM. Qualifier flags can take the following value (which is also the default):

cisc Count TC to MS transfers.
p4-uop-queue-writes [,mask= flags]
  (TS event) Count the number of valid uops written to the uop queue. Qualifier flags is a list of the following strings, separated by +’ characters:

from-tc-build
  Count uops being written from the trace cache in build mode.
from-tc-deliver
  Count uops being written from the trace cache in deliver mode.
from-rom
  Count uops being written from microcode ROM.

The default qualifier counts all the above kinds of uops.
p4-uop-type [,mask= flags]
  (TS event) This event is used in conjunction with the front-end at-retirement mechanism to tag load and store uops. Qualifer flags comprises the following strings separated by +’ characters:

tagloads
  Mark uops that are load operations.
tagstores
  Mark uops that are store operations.

The default qualifier counts both kinds of uops.
p4-uops-retired [,mask= flags]
  (TS event) Count uops retired during a clock cycle. Qualifier flags comprises the following strings separated by +’ characters:

nbogus
  Count marked uops that are not bogus.
bogus Count marked uops that are bogus.

The default qualifier counts both kinds of uops.
p4-wc-buffer [,mask= flags]
  (TI event) Count write-combining buffer operations. Qualifier flags contains the following strings separated by +’ characters:

wcb-evicts
  WC buffer evictions due to any cause.
wcb-full-evict
  WC buffer evictions due to no WC buffer being available.

The default qualifer counts both kinds of evictions.
p4-x87-assist [,mask= flags]
  (TS event) Count the retirement of x87 instructions that required special handling. Qualifier flags contains the following strings separated by +’ characters:

fpsu Count instructions that saw an FP stack underflow.
fpso Count instructions that saw an FP stack overflow.
poao Count instructions that saw an x87 output overflow.
poau Count instructions that saw an x87 output underflow.
prea Count instructions that needed an x87 input assist.

The default qualifier counts all the above types of instruction retirements.
p4-x87-fp-uop [,mask= flags]
  (TI event) Count x87 floating-point uops. Qualifier flags can take the following value (which is also the default):

all Count all x87 floating-point uops.

If an instruction contains more than one x87 floating-point uops, then all x87 floating-point uops will be counted. This event does not count x87 floating-point data movement operations.
p4-x87-simd-moves-uop [,mask= flags]
  (TI event) Count each x87 FPU, MMX, SSE, or SSE2 uops that load data or store data or perform register-to-register moves. This event does not count integer move uops. Qualifier flags may contain the following keywords separated by +’ characters:

allp0 Count all x87 and SIMD store and move uops.
allp2 Count all x87 and SIMD load uops.

The default is to count all uops. (Errata) This event may be affected by processor errata N43.

    Cascading P4 PMCs

PMC cascading support is currently poorly implemented. While individual event counters may be allocated with a "cascade" qualifier, the current API does not offer the ability to name and allocate all the resources needed for a cascaded event counter pair in a single operation.

    Precise Event Based Sampling

Support for precise event based sampling is currently unimplemented in hwpmc(4).

IMPLEMENTATION NOTES

On the i386 architecture,
.Fx has historically allowed the use of the RDTSC instruction from user-mode (i.e., at a processor CPL of 3) by any process. This behaviour is preserved by hwpmc(4).

RETURN VALUES

The pmc_name_of_capability, pmc_name_of_class, pmc_name_of_cputype, pmc_name_of_disposition, pmc_name_of_event, pmc_name_of_mode, and pmc_name_of_state functions return a pointer to the human readable form of their argument. These pointers may point to statically allocated storage and must not be passed to free. In case of an error, these functions return NULL and set the global variable errno.

The functions pmc_ncpu and pmc_npmc return the number of CPUs and number of PMCs configured respectively; in case of an error they return the value -1 and set the global variable errno.

All other functions return the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indicate the error.

COMPATIBILITY

The interface between the pmc(3) library and the hwpmc(4) driver is intended to be private to the implementation and may change. In order to ease forward compatibility with future versions of the hwpmc(4) driver, applications are urged to dynamically link with the pmc(3) library.

The pmc(3) API is
.Ud

ERRORS

A call to pmc_init may fail with the following errors in addition to those returned by modfind(2), modstat(2) and hwpmc(4):
[ENXIO]
  An unknown CPU type was encountered during initialization.
[EPROGMISMATCH]
  The version number of the hwpmc(4) kernel module did not match that compiled into the pmc(3) library.

A call to pmc_capabilities, pmc_name_of_capability, pmc_name_of_disposition, pmc_name_of_state, pmc_name_of_event, pmc_name_of_mode pmc_name_of_class and pmc_width may fail with the following error:
[EINVAL]
  An invalid argument was passed to the function.

A call to pmc_cpuinfo or pmc_ncpu may fail with the following error:
[ENXIO]
  The pmc(3) has not been initialized.

A call to pmc_npmc may fail with the following errors:
[EINVAL]
  The argument passed in was out of range.
[ENXIO]
  The pmc(3) library has not been initialized.

A call to pmc_pmcinfo may fail with the following errors, in addition to those returned by hwpmc(4):
[ENXIO]
  The pmc(3) library is not yet initialized.

A call to pmc_allocate may fail with the following errors, in addition to those returned by hwpmc(4):
[EINVAL]
  The mode argument passed in had an illegal value, or the event specification ctrspec was unrecognized for this CPU type.

Calls to pmc_attach, pmc_configure_logfile, pmc_detach, pmc_disable, pmc_enable, pmc_get_driver_stats, pmc_get_msr, pmc_read, pmc_release, pmc_rw, pmc_set, pmc_start, pmc_stop, pmc_write, and pmc_writelog may fail with the errors described in hwpmc(4).

If a log file was configured using pmc_configure_logfile and the hwpmc(4) driver encountered an error while logging data to it, then logging will be stopped and a subsequent call to pmc_flush_logfile will fail with the error code seen by the hwpmc(4) driver.

SEE ALSO

modfind(2), modstat(2), calloc(3), pmclog(3), hwpmc(4), pmccontrol(8), pmcstat(8)

HISTORY

The pmc(3) library first appeared in
.Fx 6.0 .

BUGS

The information returned by pmc_cpuinfo, pmc_ncpu and possibly pmc_npmc should really be available all the time, through a better designed interface and not just when hwpmc(4) is present in the kernel.
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March 19, 2006 PMC (3)

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