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PMC.WESTMERE(3) FreeBSD Library Functions Manual PMC.WESTMERE(3)
NAME
pmc.westmere - measurement events for Intel Westmere family CPUs
LIBRARY
Performance Counters Library (libpmc, -lpmc)
SYNOPSIS
#include <pmc.h>
DESCRIPTION
Intel Westmere CPUs contain PMCs conforming to version 2 of the Intel
performance measurement architecture. These CPUs may contain up to three
classes of PMCs:
PMC_CLASS_IAF Fixed-function counters that count only one hardware
event per counter.
PMC_CLASS_IAP Programmable counters that may be configured to count
one of a defined set of hardware events.
The number of PMCs available in each class and their widths need to be
determined at run time by calling pmc_cpuinfo(3).
Intel Westmere PMCs are documented in Volume 3B: System Programming
Guide, Part 2, Intel(R) 64 and IA-32 Architectures Software Developes
Manual, Order Number: 253669-033US, Intel Corporation, December 2009.
WESTMERE FIXED FUNCTION PMCS
These PMCs and their supported events are documented in pmc.iaf(3).
WESTMERE PROGRAMMABLE PMCS
The programmable PMCs support the following capabilities:
Capability Support
PMC_CAP_CASCADE No
PMC_CAP_EDGE Yes
PMC_CAP_INTERRUPT Yes
PMC_CAP_INVERT Yes
PMC_CAP_READ Yes
PMC_CAP_PRECISE No
PMC_CAP_SYSTEM Yes
PMC_CAP_TAGGING No
PMC_CAP_THRESHOLD Yes
PMC_CAP_USER Yes
PMC_CAP_WRITE Yes
Event Qualifiers
Event specifiers for these PMCs support the following common qualifiers:
rsp=value
Configure the Off-core Response bits.
DMND_DATA_RD
Counts the number of demand and DCU prefetch data reads
of full and partial cachelines as well as demand data
page table entry cacheline reads. Does not count L2 data
read prefetches or instruction fetches.
Counts the number of demand and DCU prefetch instruction
cacheline reads. Does not count L2 code read prefetches.
WB Counts the number of writeback (modified to exclusive)
transactions.
PF_DATA_RD
Counts the number of data cacheline reads generated by L2
prefetchers.
PF_RFO Counts the number of RFO requests generated by L2
prefetchers.
PF_IFETCH
Counts the number of code reads generated by L2
prefetchers.
OTHER Counts one of the following transaction types, including
L3 invalidate, I/O, full or partial writes, WC or non-
temporal stores, CLFLUSH, Fences, lock, unlock, split
lock.
UNCORE_HIT
L3 Hit: local or remote home requests that hit L3 cache
in the uncore with no coherency actions required
(snooping).
OTHER_CORE_HIT_SNP
L3 Hit: local or remote home requests that hit L3 cache
in the uncore and was serviced by another core with a
cross core snoop where no modified copies were found
(clean).
OTHER_CORE_HITM
L3 Hit: local or remote home requests that hit L3 cache
in the uncore and was serviced by another core with a
cross core snoop where modified copies were found (HITM).
REMOTE_CACHE_FWD
L3 Miss: local homed requests that missed the L3 cache
and was serviced by forwarded data following a cross
package snoop where no modified copies found. (Remote
home requests are not counted)
REMOTE_DRAM
L3 Miss: remote home requests that missed the L3 cache
and were serviced by remote DRAM.
LOCAL_DRAM
L3 Miss: local home requests that missed the L3 cache and
were serviced by local DRAM.
NON_DRAM
Non-DRAM requests that were serviced by IOH.
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 de-asserted to asserted
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.
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.
Event Specifiers (Programmable PMCs)
Westmere programmable PMCs support the following events:
LOAD_BLOCK.OVERLAP_STORE
(Event 03H, Umask 02H) Loads that partially overlap an earlier
store
SB_DRAIN.ANY
(Event 04H, Umask 07H) All Store buffer stall cycles
MISALIGN_MEMORY.STORE
(Event 05H, Umask 02H) All store referenced with misaligned
address
STORE_BLOCKS.AT_RET
(Event 06H, Umask 04H) Counts number of loads delayed with at-
Retirement block code. The following loads need to be executed
at retirement and wait for all senior stores on the same thread
to be drained: load splitting across 4K boundary (page split),
load accessing uncacheable (UC or USWC) memory, load lock, and
load with page table in UC or USWC memory region.
STORE_BLOCKS.L1D_BLOCK
(Event 06H, Umask 08H) Cacheable loads delayed with L1D block
code
PARTIAL_ADDRESS_ALIAS
(Event 07H, Umask 01H) Counts false dependency due to partial
address aliasing
DTLB_LOAD_MISSES.ANY
(Event 08H, Umask 01H) Counts all load misses that cause a page
walk
DTLB_LOAD_MISSES.WALK_COMPLETED
(Event 08H, Umask 02H) Counts number of completed page walks due
to load miss in the STLB.
DTLB_LOAD_MISSES.WALK_CYCLES
(Event 08H, Umask 04H) Cycles PMH is busy with a page walk due to
a load miss in the STLB.
DTLB_LOAD_MISSES.STLB_HIT
(Event 08H, Umask 10H) Number of cache load STLB hits
DTLB_LOAD_MISSES.PDE_MISS
(Event 08H, Umask 20H) Number of DTLB cache load misses where the
MEM_INST_RETIRED.STORES
(Event 0BH, Umask 02H) Counts the number of instructions with an
architecturally-visible store retired on the architected path.
In conjunction with ld_lat facility
MEM_INST_RETIRED.LATENCY_ABOVE_THRESHOLD
(Event 0BH, Umask 10H) Counts the number of instructions
exceeding the latency specified with ld_lat facility. In
conjunction with ld_lat facility
MEM_STORE_RETIRED.DTLB_MISS
(Event 0CH, Umask 01H) The event counts the number of retired
stores that missed the DTLB. The DTLB miss is not counted if the
store operation causes a fault. Does not counter prefetches.
Counts both primary and secondary misses to the TLB
UOPS_ISSUED.ANY
(Event 0EH, Umask 01H) Counts the number of Uops issued by the
Register Allocation Table to the Reservation Station, i.e. the
UOPs issued from the front end to the back end.
UOPS_ISSUED.STALLED_CYCLES
(Event 0EH, Umask 01H) Counts the number of cycles no Uops issued
by the Register Allocation Table to the Reservation Station, i.e.
the UOPs issued from the front end to the back end. set
invert=1, cmask = 1
UOPS_ISSUED.FUSED
(Event 0EH, Umask 02H) Counts the number of fused Uops that were
issued from the Register Allocation Table to the Reservation
Station.
MEM_UNCORE_RETIRED.LOCAL_HITM
(Event 0FH, Umask 02H) Load instructions retired that HIT
modified data in sibling core (Precise Event)
MEM_UNCORE_RETIRED.LOCAL_DRAM_AND_REMOTE_CACHE_HIT
(Event 0FH, Umask 08H) Load instructions retired local dram and
remote cache HIT data sources (Precise Event)
MEM_UNCORE_RETIRED.LOCAL_DRAM
(Event 0FH, Umask 10H) Load instructions retired with a data
source of local DRAM or locally homed remote cache HITM (Precise
Event)
MEM_UNCORE_RETIRED.REMOTE_DRAM
(Event 0FH, Umask 20H) Load instructions retired remote DRAM and
remote home-remote cache HITM (Precise Event)
MEM_UNCORE_RETIRED.UNCACHEABLE
(Event 0FH, Umask 80H) Load instructions retired I/O (Precise
Event)
FP_COMP_OPS_EXE.X87
(Event 10H, Umask 01H) Counts the number of FP Computational Uops
Executed. The number of FADD, FSUB, FCOM, FMULs, integer MULsand
IMULs, FDIVs, FPREMs, FSQRTS, integer DIVs, and IDIVs. This
event does not distinguish an FADD used in the middle of a
executed.
FP_COMP_OPS_EXE.SSE2_INTEGER
(Event 10H, Umask 08H) Counts number of SSE2 integer uops
executed.
FP_COMP_OPS_EXE.SSE_FP_PACKED
(Event 10H, Umask 10H) Counts number of SSE FP packed uops
executed.
FP_COMP_OPS_EXE.SSE_FP_SCALAR
(Event 10H, Umask 20H) Counts number of SSE FP scalar uops
executed.
FP_COMP_OPS_EXE.SSE_SINGLE_PRECISION
(Event 10H, Umask 40H) Counts number of SSE* FP single precision
uops executed.
FP_COMP_OPS_EXE.SSE_DOUBLE_PRECISION
(Event 10H, Umask 80H) Counts number of SSE* FP double precision
uops executed.
SIMD_INT_128.PACKED_MPY
(Event 12H, Umask 01H) Counts number of 128 bit SIMD integer
multiply operations.
SIMD_INT_128.PACKED_SHIFT
(Event 12H, Umask 02H) Counts number of 128 bit SIMD integer
shift operations.
SIMD_INT_128.PACK
(Event 12H, Umask 04H) Counts number of 128 bit SIMD integer pack
operations.
SIMD_INT_128.UNPACK
(Event 12H, Umask 08H) Counts number of 128 bit SIMD integer
unpack operations.
SIMD_INT_128.PACKED_LOGICAL
(Event 12H, Umask 10H) Counts number of 128 bit SIMD integer
logical operations.
SIMD_INT_128.PACKED_ARITH
(Event 12H, Umask 20H) Counts number of 128 bit SIMD integer
arithmetic operations.
SIMD_INT_128.SHUFFLE_MOVE
(Event 12H, Umask 40H) Counts number of 128 bit SIMD integer
shuffle and move operations.
LOAD_DISPATCH.RS
(Event 13H, Umask 01H) Counts number of loads dispatched from the
Reservation Station that bypass the Memory Order Buffer.
LOAD_DISPATCH.RS_DELAYED
(Event 13H, Umask 02H) Counts the number of delayed RS dispatches
at the stage latch. If an RS dispatch can not bypass to LB, it
has another chance to dispatch from the one-cycle delayed staging
latch before it is written into the LB.
Reservation Station.
ARITH.CYCLES_DIV_BUSY
(Event 14H, Umask 01H) Counts the number of cycles the divider is
busy executing divide or square root operations. The divide can
be integer, X87 or Streaming SIMD Extensions (SSE). The square
root operation can be either X87 or SSE. Set 'edge =1, invert=1,
cmask=1' to count the number of divides. Count may be incorrect
When SMT is on
ARITH.MUL
(Event 14H, Umask 02H) Counts the number of multiply operations
executed. This includes integer as well as floating point
multiply operations but excludes DPPS mul and MPSAD. Count may
be incorrect When SMT is on
INST_QUEUE_WRITES
(Event 17H, Umask 01H) Counts the number of instructions written
into the instruction queue every cycle.
INST_DECODED.DEC0
(Event 18H, Umask 01H) Counts number of instructions that require
decoder 0 to be decoded. Usually, this means that the
instruction maps to more than 1 uop
TWO_UOP_INSTS_DECODED
(Event 19H, Umask 01H) An instruction that generates two uops was
decoded
INST_QUEUE_WRITE_CYCLES
(Event 1EH, Umask 01H) This event counts the number of cycles
during which instructions are written to the instruction queue.
Dividing this counter by the number of instructions written to
the instruction queue (INST_QUEUE_WRITES) yields the average
number of instructions decoded each cycle. If this number is
less than four and the pipe stalls, this indicates that the
decoder is failing to decode enough instructions per cycle to
sustain the 4-wide pipeline. If SSE* instructions that are 6
bytes or longer arrive one after another, then front end
throughput may limit execution speed. In such case,
LSD_OVERFLOW
(Event 20H, Umask 01H) Number of loops that can not stream from
the instruction queue.
L2_RQSTS.LD_HIT
(Event 24H, Umask 01H) Counts number of loads that hit the L2
cache. L2 loads include both L1D demand misses as well as L1D
prefetches. L2 loads can be rejected for various reasons. Only
non rejected loads are counted.
L2_RQSTS.LD_MISS
(Event 24H, Umask 02H) Counts the number of loads that miss the
L2 cache. L2 loads include both L1D demand misses as well as L1D
prefetches.
L2_RQSTS.LOADS
(Event 24H, Umask 03H) Counts all L2 load requests. L2 loads
include both L1D demand misses as well as L1D prefetches.
L2_RQSTS.RFO_MISS
(Event 24H, Umask 08H) Counts the number of store RFO requests
that miss the L2 cache. L2 RFO requests include both L1D demand
RFO misses as well as L1D RFO prefetches.
L2_RQSTS.RFOS
(Event 24H, Umask 0CH) Counts all L2 store RFO requests. L2 RFO
requests include both L1D demand RFO misses as well as L1D RFO
prefetches.
L2_RQSTS.IFETCH_HIT
(Event 24H, Umask 10H) Counts number of instruction fetches that
hit the L2 cache. L2 instruction fetches include both L1I demand
misses as well as L1I instruction prefetches.
L2_RQSTS.IFETCH_MISS
(Event 24H, Umask 20H) Counts number of instruction fetches that
miss the L2 cache. L2 instruction fetches include both L1I
demand misses as well as L1I instruction prefetches.
L2_RQSTS.IFETCHES
(Event 24H, Umask 30H) Counts all instruction fetches. L2
instruction fetches include both L1I demand misses as well as L1I
instruction prefetches.
L2_RQSTS.PREFETCH_HIT
(Event 24H, Umask 40H) Counts L2 prefetch hits for both code and
data.
L2_RQSTS.PREFETCH_MISS
(Event 24H, Umask 80H) Counts L2 prefetch misses for both code
and data.
L2_RQSTS.PREFETCHES
(Event 24H, Umask C0H) Counts all L2 prefetches for both code and
data.
L2_RQSTS.MISS
(Event 24H, Umask AAH) Counts all L2 misses for both code and
data.
L2_RQSTS.REFERENCES
(Event 24H, Umask FFH) Counts all L2 requests for both code and
data.
L2_DATA_RQSTS.DEMAND.I_STATE
(Event 26H, Umask 01H) Counts number of L2 data demand loads
where the cache line to be loaded is in the I (invalid) state,
i.e. a cache miss. L2 demand loads are both L1D demand misses
and L1D prefetches.
L2_DATA_RQSTS.DEMAND.S_STATE
(Event 26H, Umask 02H) Counts number of L2 data demand loads
where the cache line to be loaded is in the S (shared) state. L2
demand loads are both L1D demand misses and L1D prefetches.
L2_DATA_RQSTS.DEMAND.E_STATE
(Event 26H, Umask 04H) Counts number of L2 data demand loads
L2_DATA_RQSTS.DEMAND.MESI
(Event 26H, Umask 0FH) Counts all L2 data demand requests. L2
demand loads are both L1D demand misses and L1D prefetches.
L2_DATA_RQSTS.PREFETCH.I_STATE
(Event 26H, Umask 10H) Counts number of L2 prefetch data loads
where the cache line to be loaded is in the I (invalid) state,
i.e. a cache miss.
L2_DATA_RQSTS.PREFETCH.S_STATE
(Event 26H, Umask 20H) Counts number of L2 prefetch data loads
where the cache line to be loaded is in the S (shared) state. A
prefetch RFO will miss on an S state line, while a prefetch read
will hit on an S state line.
L2_DATA_RQSTS.PREFETCH.E_STATE
(Event 26H, Umask 40H) Counts number of L2 prefetch data loads
where the cache line to be loaded is in the E (exclusive) state.
L2_DATA_RQSTS.PREFETCH.M_STATE
(Event 26H, Umask 80H) Counts number of L2 prefetch data loads
where the cache line to be loaded is in the M (modified) state.
L2_DATA_RQSTS.PREFETCH.MESI
(Event 26H, Umask F0H) Counts all L2 prefetch requests.
L2_DATA_RQSTS.ANY
(Event 26H, Umask FFH) Counts all L2 data requests.
L2_WRITE.RFO.I_STATE
(Event 27H, Umask 01H) Counts number of L2 demand store RFO
requests where the cache line to be loaded is in the I (invalid)
state, i.e, a cache miss. The L1D prefetcher does not issue a
RFO prefetch. This is a demand RFO request
L2_WRITE.RFO.S_STATE
(Event 27H, Umask 02H) Counts number of L2 store RFO requests
where the cache line to be loaded is in the S (shared) state.
The L1D prefetcher does not issue a RFO prefetch. This is a
demand RFO request.
L2_WRITE.RFO.M_STATE
(Event 27H, Umask 08H) Counts number of L2 store RFO requests
where the cache line to be loaded is in the M (modified) state.
The L1D prefetcher does not issue a RFO prefetch. This is a
demand RFO request.
L2_WRITE.RFO.HIT
(Event 27H, Umask 0EH) Counts number of L2 store RFO requests
where the cache line to be loaded is in either the S, E or M
states. The L1D prefetcher does not issue a RFO prefetch. This
is a demand RFO request
L2_WRITE.RFO.MESI
(Event 27H, Umask 0FH) Counts all L2 store RFO requests.The L1D
prefetcher does not issue a RFO prefetch. This is a demand RFO
request.
where the cache line to be loaded is in the S (shared) state.
L2_WRITE.LOCK.E_STATE
(Event 27H, Umask 40H) Counts number of L2 demand lock RFO
requests where the cache line to be loaded is in the E
(exclusive) state.
L2_WRITE.LOCK.M_STATE
(Event 27H, Umask 80H) Counts number of L2 demand lock RFO
requests where the cache line to be loaded is in the M (modified)
state.
L2_WRITE.LOCK.HIT
(Event 27H, Umask E0H) Counts number of L2 demand lock RFO
requests where the cache line to be loaded is in either the S, E,
or M state.
L2_WRITE.LOCK.MESI
(Event 27H, Umask F0H) Counts all L2 demand lock RFO requests.
L1D_WB_L2.I_STATE
(Event 28H, Umask 01H) Counts number of L1 writebacks to the L2
where the cache line to be written is in the I (invalid) state,
i.e. a cache miss.
L1D_WB_L2.S_STATE
(Event 28H, Umask 02H) Counts number of L1 writebacks to the L2
where the cache line to be written is in the S state.
L1D_WB_L2.E_STATE
(Event 28H, Umask 04H) Counts number of L1 writebacks to the L2
where the cache line to be written is in the E (exclusive) state.
L1D_WB_L2.M_STATE
(Event 28H, Umask 08H) Counts number of L1 writebacks to the L2
where the cache line to be written is in the M (modified) state.
L1D_WB_L2.MESI
(Event 28H, Umask 0FH) Counts all L1 writebacks to the L2.
L3_LAT_CACHE.REFERENCE
(Event 2EH, Umask 02H) Counts uncore Last Level Cache references.
Because cache hierarchy, cache sizes and other implementation-
specific characteristics; value comparison to estimate
performance differences is not recommended. See Table A-1.
L3_LAT_CACHE.MISS
(Event 2EH, Umask 01H) Counts uncore Last Level Cache misses.
Because cache hierarchy, cache sizes and other implementation-
specific characteristics; value comparison to estimate
performance differences is not recommended. See Table A-1.
CPU_CLK_UNHALTED.THREAD_P
(Event 3CH, Umask 00H) Counts the number of thread cycles while
the thread is not in a halt state. The thread enters the halt
state when it is running the HLT instruction. The core frequency
may change from time to time due to power or thermal throttling.
see Table A-1
DTLB_MISSES.WALK_COMPLETED
(Event 49H, Umask 02H) Counts number of misses in the STLB which
resulted in a completed page walk.
DTLB_MISSES.WALK_CYCLES
(Event 49H, Umask 04H) Counts cycles of page walk due to misses
in the STLB.
DTLB_MISSES.STLB_HIT
(Event 49H, Umask 10H) Counts the number of DTLB first level
misses that hit in the second level TLB. This event is only
relevant if the core contains multiple DTLB levels.
DTLB_MISSES.LARGE_WALK_COMPLETED
(Event 49H, Umask 80H) Counts number of completed large page
walks due to misses in the STLB.
LOAD_HIT_PRE
(Event 4CH, Umask 01H) Counts load operations sent to the L1 data
cache while a previous SSE prefetch instruction to the same cache
line has started prefetching but has not yet finished.
L1D_PREFETCH.REQUESTS
(Event 4EH, Umask 01H) Counts number of hardware prefetch
requests dispatched out of the prefetch FIFO.
L1D_PREFETCH.MISS
(Event 4EH, Umask 02H) Counts number of hardware prefetch
requests that miss the L1D. There are two prefetchers in the
L1D. A streamer, which predicts lines sequentially after this
one should be fetched, and the IP prefetcher that remembers
access patterns for the current instruction. The streamer
prefetcher stops on an L1D hit, while the IP prefetcher does not.
L1D_PREFETCH.TRIGGERS
(Event 4EH, Umask 04H) Counts number of prefetch requests
triggered by the Finite State Machine and pushed into the
prefetch FIFO. Some of the prefetch requests are dropped due to
overwrites or competition between the IP index prefetcher and
streamer prefetcher. The prefetch FIFO contains 4 entries.
EPT.WALK_CYCLES
(Event 4FH, Umask 10H) Counts Extended Page walk cycles.
L1D.REPL
(Event 51H, Umask 01H) Counts the number of lines brought into
the L1 data cache. Counter 0, 1 only.
L1D.M_REPL
(Event 51H, Umask 02H) Counts the number of modified lines
brought into the L1 data cache. Counter 0, 1 only.
L1D.M_EVICT
(Event 51H, Umask 04H) Counts the number of modified lines
evicted from the L1 data cache due to replacement. Counter 0, 1
only.
L1D.M_SNOOP_EVICT
L1D_CACHE_LOCK_FB_HIT
(Event 53H, Umask 01H) Counts the number of cacheable load lock
speculated or retired instructions accepted into the fill buffer.
OFFCORE_REQUESTS_OUTSTANDING.DEMAND.READ_DATA
(Event 60H, Umask 01H) Counts weighted cycles of offcore demand
data read requests. Does not include L2 prefetch requests.
Counter 0.
OFFCORE_REQUESTS_OUTSTANDING.DEMAND.READ_CODE
(Event 60H, Umask 02H) Counts weighted cycles of offcore demand
code read requests. Does not include L2 prefetch requests.
Counter 0.
OFFCORE_REQUESTS_OUTSTANDING.DEMAND.RFO
(Event 60H, Umask 04H) Counts weighted cycles of offcore demand
RFO requests. Does not include L2 prefetch requests. Counter 0.
OFFCORE_REQUESTS_OUTSTANDING.ANY.READ
(Event 60H, Umask 08H) Counts weighted cycles of offcore read
requests of any kind. Include L2 prefetch requests. Counter 0.
CACHE_LOCK_CYCLES.L1D_L2
(Event 63H, Umask 01H) Cycle count during which the L1D and L2
are locked. A lock is asserted when there is a locked memory
access, due to uncacheable memory, a locked operation that spans
two cache lines, or a page walk from an uncacheable page table.
Counter 0, 1 only. L1D and L2 locks have a very high performance
penalty and it is highly recommended to avoid such accesses.
CACHE_LOCK_CYCLES.L1D
(Event 63H, Umask 02H) Counts the number of cycles that cacheline
in the L1 data cache unit is locked. Counter 0, 1 only.
IO_TRANSACTIONS
(Event 6CH, Umask 01H) Counts the number of completed I/O
transactions.
L1I.HITS
(Event 80H, Umask 01H) Counts all instruction fetches that hit
the L1 instruction cache.
L1I.MISSES
(Event 80H, Umask 02H) Counts all instruction fetches that miss
the L1I cache. This includes instruction cache misses, streaming
buffer misses, victim cache misses and uncacheable fetches. An
instruction fetch miss is counted only once and not once for
every cycle it is outstanding.
L1I.READS
(Event 80H, Umask 03H) Counts all instruction fetches, including
uncacheable fetches that bypass the L1I.
L1I.CYCLES_STALLED
(Event 80H, Umask 04H) Cycle counts for which an instruction
fetch stalls due to a L1I cache miss, ITLB miss or ITLB fault.
LARGE_ITLB.HIT
(Event 85H, Umask 02H) Counts number of misses in all levels of
the ITLB which resulted in a completed page walk.
ITLB_MISSES.WALK_CYCLES
(Event 85H, Umask 04H) Counts ITLB miss page walk cycles.
ITLB_MISSES.LARGE_WALK_COMPLETED
(Event 85H, Umask 80H) Counts number of completed large page
walks due to misses in the STLB.
ILD_STALL.LCP
(Event 87H, Umask 01H) Cycles Instruction Length Decoder stalls
due to length changing prefixes: 66, 67 or REX.W (for EM64T)
instructions which change the length of the decoded instruction.
ILD_STALL.MRU
(Event 87H, Umask 02H) Instruction Length Decoder stall cycles
due to Brand Prediction Unit (PBU) Most Recently Used (MRU)
bypass.
ILD_STALL.IQ_FULL
(Event 87H, Umask 04H) Stall cycles due to a full instruction
queue.
ILD_STALL.REGEN
(Event 87H, Umask 08H) Counts the number of regen stalls.
ILD_STALL.ANY
(Event 87H, Umask 0FH) Counts any cycles the Instruction Length
Decoder is stalled.
BR_INST_EXEC.COND
(Event 88H, Umask 01H) Counts the number of conditional near
branch instructions executed, but not necessarily retired.
BR_INST_EXEC.DIRECT
(Event 88H, Umask 02H) Counts all unconditional near branch
instructions excluding calls and indirect branches.
BR_INST_EXEC.INDIRECT_NON_CALL
(Event 88H, Umask 04H) Counts the number of executed indirect
near branch instructions that are not calls.
BR_INST_EXEC.NON_CALLS
(Event 88H, Umask 07H) Counts all non call near branch
instructions executed, but not necessarily retired.
BR_INST_EXEC.RETURN_NEAR
(Event 88H, Umask 08H) Counts indirect near branches that have a
return mnemonic.
BR_INST_EXEC.DIRECT_NEAR_CALL
(Event 88H, Umask 10H) Counts unconditional near call branch
instructions, excluding non call branch, executed.
BR_INST_EXEC.INDIRECT_NEAR_CALL
(Event 88H, Umask 20H) Counts indirect near calls, including both
register and memory indirect, executed.
BR_INST_EXEC.ANY
(Event 88H, Umask 7FH) Counts all near executed branches (not
necessarily retired). This includes only instructions and not
micro-op branches. Frequent branching is not necessarily a major
performance issue. However frequent branch mispredictions may be
a problem.
BR_MISP_EXEC.COND
(Event 89H, Umask 01H) Counts the number of mispredicted
conditional near branch instructions executed, but not
necessarily retired.
BR_MISP_EXEC.DIRECT
(Event 89H, Umask 02H) Counts mispredicted macro unconditional
near branch instructions, excluding calls and indirect branches
(should always be 0).
BR_MISP_EXEC.INDIRECT_NON_CALL
(Event 89H, Umask 04H) Counts the number of executed mispredicted
indirect near branch instructions that are not calls.
BR_MISP_EXEC.NON_CALLS
(Event 89H, Umask 07H) Counts mispredicted non call near branches
executed, but not necessarily retired.
BR_MISP_EXEC.RETURN_NEAR
(Event 89H, Umask 08H) Counts mispredicted indirect branches that
have a rear return mnemonic.
BR_MISP_EXEC.DIRECT_NEAR_CALL
(Event 89H, Umask 10H) Counts mispredicted non-indirect near
calls executed, (should always be 0).
BR_MISP_EXEC.INDIRECT_NEAR_CALL
(Event 89H, Umask 20H) Counts mispredicted indirect near calls
executed, including both register and memory indirect.
BR_MISP_EXEC.NEAR_CALLS
(Event 89H, Umask 30H) Counts all mispredicted near call branches
executed, but not necessarily retired.
BR_MISP_EXEC.TAKEN
(Event 89H, Umask 40H) Counts executed mispredicted near branches
that are taken, but not necessarily retired.
BR_MISP_EXEC.ANY
(Event 89H, Umask 7FH) Counts the number of mispredicted near
branch instructions that were executed, but not necessarily
retired.
RESOURCE_STALLS.ANY
(Event A2H, Umask 01H) Counts the number of Allocator resource
related stalls. Includes register renaming buffer entries,
memory buffer entries. In addition to resource related stalls,
this event counts some other events. Includes stalls arising
during branch misprediction recovery, such as if retirement of
the mispredicted branch is delayed and stalls arising while store
buffer is draining from synchronizing operations. Does not
RESOURCE_STALLS.RS_FULL
(Event A2H, Umask 04H) This event counts the number of cycles
when the number of instructions in the pipeline waiting for
execution reaches the limit the processor can handle. A high
count of this event indicates that there are long latency
operations in the pipe (possibly load and store operations that
miss the L2 cache, or instructions dependent upon instructions
further down the pipeline that have yet to retire. When RS is
full, new instructions can not enter the reservation station and
start execution.
RESOURCE_STALLS.STORE
(Event A2H, Umask 08H) This event counts the number of cycles
that a resource related stall will occur due to the number of
store instructions reaching the limit of the pipeline, (i.e. all
store buffers are used). The stall ends when a store instruction
commits its data to the cache or memory.
RESOURCE_STALLS.ROB_FULL
(Event A2H, Umask 10H) Counts the cycles of stall due to re-
order buffer full.
RESOURCE_STALLS.FPCW
(Event A2H, Umask 20H) Counts the number of cycles while
execution was stalled due to writing the floating-point unit
(FPU) control word.
RESOURCE_STALLS.MXCSR
(Event A2H, Umask 40H) Stalls due to the MXCSR register rename
occurring to close to a previous MXCSR rename. The MXCSR
provides control and status for the MMX registers.
RESOURCE_STALLS.OTHER
(Event A2H, Umask 80H) Counts the number of cycles while
execution was stalled due to other resource issues.
MACRO_INSTS.FUSIONS_DECODED
(Event A6H, Umask 01H) Counts the number of instructions decoded
that are macro-fused but not necessarily executed or retired.
BACLEAR_FORCE_IQ
(Event A7H, Umask 01H) Counts number of times a BACLEAR was
forced by the Instruction Queue. The IQ is also responsible for
providing conditional branch prediction direction based on a
static scheme and dynamic data provided by the L2 Branch
Prediction Unit. If the conditional branch target is not found
in the Target Array and the IQ predicts that the branch is taken,
then the IQ will force the Branch Address Calculator to issue a
BACLEAR. Each BACLEAR asserted by the BAC generates
approximately an 8 cycle bubble in the instruction fetch
pipeline.
LSD.UOPS
(Event A8H, Umask 01H) Counts the number of micro-ops delivered
by loop stream detector Use cmask=1 and invert to count cycles
ITLB_FLUSH
(Event AEH, Umask 01H) Counts the number of ITLB flushes
OFFCORE_REQUESTS.DEMAND.RFO
(Event B0H, Umask 04H) Counts number of offcore demand RFO
requests. Does not count L2 prefetch requests.
OFFCORE_REQUESTS.ANY.READ
(Event B0H, Umask 08H) Counts number of offcore read requests.
Includes L2 prefetch requests.
OFFCORE_REQUESTS.ANY.RFO
(Event 80H, Umask 10H) Counts number of offcore RFO requests.
Includes L2 prefetch requests.
OFFCORE_REQUESTS.L1D_WRITEBACK
(Event B0H, Umask 40H) Counts number of L1D writebacks to the
uncore.
OFFCORE_REQUESTS.ANY
(Event B0H, Umask 80H) Counts all offcore requests.
UOPS_EXECUTED.PORT0
(Event B1H, Umask 01H) Counts number of Uops executed that were
issued on port 0. Port 0 handles integer arithmetic, SIMD and FP
add Uops.
UOPS_EXECUTED.PORT1
(Event B1H, Umask 02H) Counts number of Uops executed that were
issued on port 1. Port 1 handles integer arithmetic, SIMD,
integer shift, FP multiply and FP divide Uops.
UOPS_EXECUTED.PORT2_CORE
(Event B1H, Umask 04H) Counts number of Uops executed that were
issued on port 2. Port 2 handles the load Uops. This is a core
count only and can not be collected per thread.
UOPS_EXECUTED.PORT3_CORE
(Event B1H, Umask 08H) Counts number of Uops executed that were
issued on port 3. Port 3 handles store Uops. This is a core
count only and can not be collected per thread.
UOPS_EXECUTED.PORT4_CORE
(Event B1H, Umask 10H) Counts number of Uops executed that where
issued on port 4. Port 4 handles the value to be stored for the
store Uops issued on port 3. This is a core count only and can
not be collected per thread.
UOPS_EXECUTED.CORE_ACTIVE_CYCLES_NO_PORT5
(Event B1H, Umask 1FH) Counts number of cycles there are one or
more uops being executed and were issued on ports 0-4. This is a
core count only and can not be collected per thread.
UOPS_EXECUTED.PORT5
(Event B1H, Umask 20H) Counts number of Uops executed that where
issued on port 5.
UOPS_EXECUTED.CORE_ACTIVE_CYCLES
(Event B1H, Umask 3FH) Counts number of cycles there are one or
more uops being executed on any ports. This is a core count only
and can not be collected per thread.
(Event B1H, Umask 80H) Counts number of Uops executed that where
issued on port 2, 3, or 4.
OFFCORE_REQUESTS_SQ_FULL
(Event B2H, Umask 01H) Counts number of cycles the SQ is full to
handle off-core requests.
SNOOPQ_REQUESTS_OUTSTANDING.DATA
(Event B3H, Umask 01H) Counts weighted cycles of snoopq requests
for data. Counter 0 only Use cmask=1 to count cycles not empty.
SNOOPQ_REQUESTS_OUTSTANDING.INVALIDATE
(Event B3H, Umask 02H) Counts weighted cycles of snoopq
invalidate requests. Counter 0 only. Use cmask=1 to count
cycles not empty.
SNOOPQ_REQUESTS_OUTSTANDING.CODE
(Event B3H, Umask 04H) Counts weighted cycles of snoopq requests
for code. Counter 0 only. Use cmask=1 to count cycles not
empty.
SNOOPQ_REQUESTS.CODE
(Event B4H, Umask 01H) Counts the number of snoop code requests.
SNOOPQ_REQUESTS.DATA
(Event B4H, Umask 02H) Counts the number of snoop data requests.
SNOOPQ_REQUESTS.INVALIDATE
(Event B4H, Umask 04H) Counts the number of snoop invalidate
requests
OFF_CORE_RESPONSE_0
(Event B7H, Umask 01H) see Section 30.6.1.3, Off-core Response
Performance Monitoring in the Processor Core. Requires
programming MSR 01A6H.
SNOOP_RESPONSE.HIT
(Event B8H, Umask 01H) Counts HIT snoop response sent by this
thread in response to a snoop request.
SNOOP_RESPONSE.HITE
(Event B8H, Umask 02H) Counts HIT E snoop response sent by this
thread in response to a snoop request.
SNOOP_RESPONSE.HITM
(Event B8H, Umask 04H) Counts HIT M snoop response sent by this
thread in response to a snoop request.
OFF_CORE_RESPONSE_1
(Event BBH, Umask 01H) see Section 30.6.1.3, Off-core Response
Performance Monitoring in the Processor Core. Use MSR 01A7H.
INST_RETIRED.ANY_P
(Event C0H, Umask 01H) See Table A-1 Notes: INST_RETIRED.ANY is
counted by a designated fixed counter. INST_RETIRED.ANY_P is
counted by a programmable counter and is an architectural
performance event. Event is supported if CPUID.A.EBX[1] = 0.
Counting: Faulting executions of GETSEC/VM entry/VM Exit/MWait
will not count as retired instructions.
INST_RETIRED.MMX
(Event C0H, Umask 04H) Counts the number of retired: MMX
instructions.
UOPS_RETIRED.ANY
(Event C2H, Umask 01H) Counts the number of micro-ops retired,
(macro-fused=1, micro- fused=2, others=1; maximum count of 8 per
cycle). Most instructions are composed of one or two micro-ops.
Some instructions are decoded into longer sequences such as
repeat instructions, floating point transcendental instructions,
and assists. Use cmask=1 and invert to count active cycles or
stalled cycles
UOPS_RETIRED.RETIRE_SLOTS
(Event C2H, Umask 02H) Counts the number of retirement slots used
each cycle
UOPS_RETIRED.MACRO_FUSED
(Event C2H, Umask 04H) Counts number of macro-fused uops retired.
MACHINE_CLEARS.CYCLES
(Event C3H, Umask 01H) Counts the cycles machine clear is
asserted.
MACHINE_CLEARS.MEM_ORDER
(Event C3H, Umask 02H) Counts the number of machine clears due to
memory order conflicts.
MACHINE_CLEARS.SMC
(Event C3H, Umask 04H) Counts the number of times that a program
writes to a code section. Self-modifying code causes a sever
penalty in all Intel 64 and IA-32 processors. The modified cache
line is written back to the L2 and L3caches.
BR_INST_RETIRED.ANY_P
(Event C4H, Umask 00H) See Table A-1.
BR_INST_RETIRED.CONDITIONAL
(Event C4H, Umask 01H) Counts the number of conditional branch
instructions retired.
BR_INST_RETIRED.NEAR_CALL
(Event C4H, Umask 02H) Counts the number of direct & indirect
near unconditional calls retired.
BR_INST_RETIRED.ALL_BRANCHES
(Event C4H, Umask 04H) Counts the number of branch instructions
retired.
BR_MISP_RETIRED.ANY_P
(Event C5H, Umask 00H) See Table A-1.
BR_MISP_RETIRED.CONDITIONAL
(Event C5H, Umask 01H) Counts mispredicted conditional retired
calls.
BR_MISP_RETIRED.NEAR_CALL
(Event C5H, Umask 02H) Counts mispredicted direct & indirect near
floating point Uops retired.
SSEX_UOPS_RETIRED.SCALAR_SINGLE
(Event C7H, Umask 02H) Counts SIMD calar single-precision
floating point Uops retired.
SSEX_UOPS_RETIRED.PACKED_DOUBLE
(Event C7H, Umask 04H) Counts SIMD packed double- precision
floating point Uops retired.
SSEX_UOPS_RETIRED.SCALAR_DOUBLE
(Event C7H, Umask 08H) Counts SIMD scalar double-precision
floating point Uops retired.
SSEX_UOPS_RETIRED.VECTOR_INTEGER
(Event C7H, Umask 10H) Counts 128-bit SIMD vector integer Uops
retired.
ITLB_MISS_RETIRED
(Event C8H, Umask 20H) Counts the number of retired instructions
that missed the ITLB when the instruction was fetched.
MEM_LOAD_RETIRED.L1D_HIT
(Event CBH, Umask 01H) Counts number of retired loads that hit
the L1 data cache.
MEM_LOAD_RETIRED.L2_HIT
(Event CBH, Umask 02H) Counts number of retired loads that hit
the L2 data cache.
MEM_LOAD_RETIRED.L3_UNSHARED_HIT
(Event CBH, Umask 04H) Counts number of retired loads that hit
their own, unshared lines in the L3 cache.
MEM_LOAD_RETIRED.OTHER_CORE_L2_HIT_HITM
(Event CBH, Umask 08H) Counts number of retired loads that hit in
a sibling core's L2 (on die core). Since the L3 is inclusive of
all cores on the package, this is an L3 hit. This counts both
clean or modified hits.
MEM_LOAD_RETIRED.L3_MISS
(Event CBH, Umask 10H) Counts number of retired loads that miss
the L3 cache. The load was satisfied by a remote socket, local
memory or an IOH.
MEM_LOAD_RETIRED.HIT_LFB
(Event CBH, Umask 40H) Counts number of retired loads that miss
the L1D and the address is located in an allocated line fill
buffer and will soon be committed to cache. This is counting
secondary L1D misses.
MEM_LOAD_RETIRED.DTLB_MISS
(Event CBH, Umask 80H) Counts the number of retired loads that
missed the DTLB. The DTLB miss is not counted if the load
operation causes a fault. This event counts loads from cacheable
memory only. The event does not count loads by software
prefetches. Counts both primary and secondary misses to the TLB.
FP_MMX_TRANS.TO_FP
a floating-point instruction. You can use this event to estimate
the penalties for the transitions between floating-point and MMX
technology states.
FP_MMX_TRANS.ANY
(Event CCH, Umask 03H) Counts all transitions from floating point
to MMX instructions and from MMX instructions to floating point
instructions. You can use this event to estimate the penalties
for the transitions between floating-point and MMX technology
states.
MACRO_INSTS.DECODED
(Event D0H, Umask 01H) Counts the number of instructions decoded,
(but not necessarily executed or retired).
UOPS_DECODED.STALL_CYCLES
(Event D1H, Umask 01H) Counts the cycles of decoder stalls.
UOPS_DECODED.MS
(Event D1H, Umask 02H) Counts the number of Uops decoded by the
Microcode Sequencer, MS. The MS delivers uops when the
instruction is more than 4 uops long or a microcode assist is
occurring.
UOPS_DECODED.ESP_FOLDING
(Event D1H, Umask 04H) Counts number of stack pointer (ESP)
instructions decoded: push , pop , call , ret, etc. ESP
instructions do not generate a Uop to increment or decrement ESP.
Instead, they update an ESP_Offset register that keeps track of
the delta to the current value of the ESP register.
UOPS_DECODED.ESP_SYNC
(Event D1H, Umask 08H) Counts number of stack pointer (ESP) sync
operations where an ESP instruction is corrected by adding the
ESP offset register to the current value of the ESP register.
RAT_STALLS.FLAGS
(Event D2H, Umask 01H) Counts the number of cycles during which
execution stalled due to several reasons, one of which is a
partial flag register stall. A partial register stall may occur
when two conditions are met: 1) an instruction modifies some, but
not all, of the flags in the flag register and 2) the next
instruction, which depends on flags, depends on flags that were
not modified by this instruction.
RAT_STALLS.REGISTERS
(Event D2H, Umask 02H) This event counts the number of cycles
instruction execution latency became longer than the defined
latency because the instruction used a register that was
partially written by previous instruction.
RAT_STALLS.ROB_READ_PORT
(Event D2H, Umask 04H) Counts the number of cycles when ROB read
port stalls occurred, which did not allow new micro-ops to enter
the out-of-order pipeline. Note that, at this stage in the
pipeline, additional stalls may occur at the same cycle and
prevent the stalled micro-ops from entering the pipe. In such a
case, micro-ops retry entering the execution pipe in the next
cycle and the ROB-read port stall is counted again.
(Event D2H, Umask 0FH) Counts all Register Allocation Table stall
cycles due to: Cycles when ROB read port stalls occurred, which
did not allow new micro-ops to enter the execution pipe. Cycles
when partial register stalls occurred Cycles when flag stalls
occurred Cycles floating-point unit (FPU) status word stalls
occurred. To count each of these conditions separately use the
events: RAT_STALLS.ROB_READ_PORT, RAT_STALLS.PARTIAL,
RAT_STALLS.FLAGS, and RAT_STALLS.FPSW.
SEG_RENAME_STALLS
(Event D4H, Umask 01H) Counts the number of stall cycles due to
the lack of renaming resources for the ES, DS, FS, and GS segment
registers. If a segment is renamed but not retired and a second
update to the same segment occurs, a stall occurs in the front-
end of the pipeline until the renamed segment retires.
ES_REG_RENAMES
(Event D5H, Umask 01H) Counts the number of times the ES segment
register is renamed.
UOP_UNFUSION
(Event DBH, Umask 01H) Counts unfusion events due to floating
point exception to a fused uop.
BR_INST_DECODED
(Event E0H, Umask 01H) Counts the number of branch instructions
decoded.
BPU_MISSED_CALL_RET
(Event E5H, Umask 01H) Counts number of times the Branch
Prediction Unit missed predicting a call or return branch.
BACLEAR.CLEAR
(Event E6H, Umask 01H) Counts the number of times the front end
is resteered, mainly when the Branch Prediction Unit cannot
provide a correct prediction and this is corrected by the Branch
Address Calculator at the front end. This can occur if the code
has many branches such that they cannot be consumed by the BPU.
Each BACLEAR asserted by the BAC generates approximately an 8
cycle bubble in the instruction fetch pipeline. The effect on
total execution time depends on the surrounding code.
BACLEAR.BAD_TARGET
(Event E6H, Umask 02H) Counts number of Branch Address Calculator
clears (BACLEAR) asserted due to conditional branch instructions
in which there was a target hit but the direction was wrong.
Each BACLEAR asserted by the BAC generates approximately an 8
cycle bubble in the instruction fetch pipeline.
BPU_CLEARS.EARLY
(Event E8H, Umask 01H) Counts early (normal) Branch Prediction
Unit clears: BPU predicted a taken branch after incorrectly
assuming that it was not taken. The BPU clear leads to 2 cycle
bubble in the Front End.
BPU_CLEARS.LATE
(Event E8H, Umask 02H) Counts late Branch Prediction Unit clears
due to Most Recently Used conflicts. The PBU clear leads to a 3
cycle bubble in the Front End.
L2_TRANSACTIONS.RFO
(Event F0H, Umask 02H) Counts L2 RFO operations due to HW
prefetch or demand RFOs.
L2_TRANSACTIONS.IFETCH
(Event F0H, Umask 04H) Counts L2 instruction fetch operations due
to HW prefetch or demand ifetch.
L2_TRANSACTIONS.PREFETCH
(Event F0H, Umask 08H) Counts L2 prefetch operations.
L2_TRANSACTIONS.L1D_WB
(Event F0H, Umask 10H) Counts L1D writeback operations to the L2.
L2_TRANSACTIONS.FILL
(Event F0H, Umask 20H) Counts L2 cache line fill operations due
to load, RFO, L1D writeback or prefetch.
L2_TRANSACTIONS.WB
(Event F0H, Umask 40H) Counts L2 writeback operations to the L3.
L2_TRANSACTIONS.ANY
(Event F0H, Umask 80H) Counts all L2 cache operations.
L2_LINES_IN.S_STATE
(Event F1H, Umask 02H) Counts the number of cache lines allocated
in the L2 cache in the S (shared) state.
L2_LINES_IN.E_STATE
(Event F1H, Umask 04H) Counts the number of cache lines allocated
in the L2 cache in the E (exclusive) state.
L2_LINES_IN.ANY
(Event F1H, Umask 07H) Counts the number of cache lines allocated
in the L2 cache.
L2_LINES_OUT.DEMAND_CLEAN
(Event F2H, Umask 01H) Counts L2 clean cache lines evicted by a
demand request.
L2_LINES_OUT.DEMAND_DIRTY
(Event F2H, Umask 02H) Counts L2 dirty (modified) cache lines
evicted by a demand request.
L2_LINES_OUT.PREFETCH_CLEAN
(Event F2H, Umask 04H) Counts L2 clean cache line evicted by a
prefetch request.
L2_LINES_OUT.PREFETCH_DIRTY
(Event F2H, Umask 08H) Counts L2 modified cache line evicted by a
prefetch request.
L2_LINES_OUT.ANY
(Event F2H, Umask 0FH) Counts all L2 cache lines evicted for any
reason.
SQ_MISC.LRU_HINTS
(Event F4H, Umask 04H) Counts number of Super Queue LRU hints
(Event F6H, Umask 01H) Counts cycles the Super Queue is full.
Neither of the threads on this core will be able to access the
uncore.
FP_ASSIST.ALL
(Event F7H, Umask 01H) Counts the number of floating point
operations executed that required micro-code assist intervention.
Assists are required in the following cases: SSE instructions,
(Denormal input when the DAZ flag is off or Underflow result when
the FTZ flag is off): x87 instructions, (NaN or denormal are
loaded to a register or used as input from memory, Division by 0
or Underflow output).
FP_ASSIST.OUTPUT
(Event F7H, Umask 02H) Counts number of floating point micro-code
assist when the output value (destination register) is invalid.
FP_ASSIST.INPUT
(Event F7H, Umask 04H) Counts number of floating point micro-code
assist when the input value (one of the source operands to an FP
instruction) is invalid.
SIMD_INT_64.PACKED_MPY
(Event FDH, Umask 01H) Counts number of SID integer 64 bit packed
multiply operations.
SIMD_INT_64.PACKED_SHIFT
(Event FDH, Umask 02H) Counts number of SID integer 64 bit packed
shift operations.
SIMD_INT_64.PACK
(Event FDH, Umask 04H) Counts number of SID integer 64 bit pack
operations.
SIMD_INT_64.UNPACK
(Event FDH, Umask 08H) Counts number of SID integer 64 bit unpack
operations.
SIMD_INT_64.PACKED_LOGICAL
(Event FDH, Umask 10H) Counts number of SID integer 64 bit
logical operations.
SIMD_INT_64.PACKED_ARITH
(Event FDH, Umask 20H) Counts number of SID integer 64 bit
arithmetic operations.
SIMD_INT_64.SHUFFLE_MOVE
(Event FDH, Umask 40H) Counts number of SID integer 64 bit shift
or move operations.
SEE ALSO
pmc(3), pmc.atom(3), pmc.core(3), pmc.corei7(3), pmc.corei7uc(3),
pmc.iaf(3), pmc.k7(3), pmc.k8(3), pmc.soft(3), pmc.tsc(3), pmc.ucf(3),
pmc.westmereuc(3), pmc_cpuinfo(3), pmclog(3), hwpmc(4)
HISTORY
The pmc library first appeared in FreeBSD 6.0.
AUTHORS