PMC.XSCALE(3)

NAME
pmc.xscale - measurement events for Intel XScale family CPUs

LIBRARY
libpmc

SYNOPSIS
#include <pmc.h>

DESCRIPTION
Intel XScale CPUs are ARM CPUs based on the ARMv5e core.

Second generation cores have 2 counters, while third generation cores have 4 counters. Third generation cores also have an increased number of PMC events.

Intel XScale PMCs are documented in 3rd Generation Intel XScale Microarchitecture Developer's Manual, May 2007.

  Event Specifiers (Programmable PMCs)
Intel XScale programmable PMCs support the following events:

IC_FETCH
    External memory fetch due to L1 instruction cache miss.

IC_MISS
    Instruction cache or TLB miss.

DATA_DEPENDENCY_STALLED
    A data dependency stalled

ITLB_MISS
    Instruction TLB miss.

DTLB_MISS
    Data TLB miss.

BRANCH_RETIRED
    Branch instruction retired (executed).

BRANCH_MISPRED
    Branch mispredicted.

INSTR_RETIRED
    Instructions retired (executed).

DC_FULL_CYCLE
    L1 data cache buffer full stall. Event occurs on every cycle the condition is present.

DC_FULL_CONTIG
    L1 data cache buffer full stall. Event occurs once for each contiguous sequence of this type of stall.

DC_ACCESS
    L1 data cache access, not including cache operations.

DC_MISS
    L1 data cache miss, not including cache operations.

DC_WRITEBACK
    L1 data cache write-back. Occurs for each cache line that's written back from the cache.

PC_CHANGE
    Software changed the program counter.

BRANCH_RETIRED_ALL
    Branch instruction retired (executed). This event counts all branch instructions, indirect or direct.

INSTR_CYCLE
    Count the number of microarchitecture cycles each instruction requires to issue.

CP_STALL
    Coprocessor stalled the instruction pipeline.

PC_CHANGE_ALL
    Software changed the program counter (includes exceptions).

PIPELINE_FLUSH
    Pipeline flushes due to mispredictions or exceptions.

BACKEND_STALL
    Backend stalled the instruction pipeline.

MULTIPLIER_USE
    Multiplier used.

MULTIPLIER_STALLED
    Multiplier stalled the instruction pipeline.

DATA_CACHE_STALLED
    Data cache stalled the instruction pipeline.

L2_CACHE_REQ
    L2 cache request, not including cache operations.

L2_CACHE_MISS
    L2 cache miss, not including cache operations.

ADDRESS_BUS_TRANS
    Address bus transaction.

SELF_ADDRESS_BUS_TRANS
    Self initiated address bus transaction.

DATA_BUS_TRANS
    Data bus transaction.

  Event Name Aliases
The following table shows the mapping between the PMC-independent aliases supported by libpmc and the underlying hardware events used.
Alias | Event |
branches | BRANCH_RETIRED |
branch-mispredicts | BRANCH_MISPRED |
dc-misses | DC_MISS |
ic-misses | IC_MISS |
instructions | INSTR_RETIRED |

SEE ALSO
pmc(3), pmc_cpuinfo(3), pmclog(3), pmc.soft(3), hwpmc(4)

HISTORY
The pmc library first appeared in FreeBSD 6.0. Intel XScale support first appeared in FreeBSD 9.0.

AUTHORS
The libpmc library was written by Joseph Koshy <jkoshy@FreeBSD.org>.

Intel XScale support was added by Rui Paulo <rpaulo@FreeBSD.org>.

CAVEATS
The Intel XScale code does not yet support sampling.