Branch History Rolling Buffer (BHRB) is a new PMU feaure in IBM
POWER8 processor which records the branch instructions inside the execution
pipeline. This patchset enables the basic functionality of the feature through
generic perf branch stack sampling framework.
Sample output
-------------
$./perf record -b top
$./perf report
Overhead Command Source Shared Object Source Symbol
Target Shared Object Target Symbol
# ........ ....... ....................
...................................... ....................
...................................
#
7.82% top libc-2.11.2.so [k] _IO_vfscanf
libc-2.11.2.so [k] _IO_vfscanf
6.17% top libc-2.11.2.so [k] _IO_vfscanf
[unknown] [k] 00000000
2.37% top [unknown] [k] 0xf7aafb30
[unknown] [k] 00000000
1.80% top [unknown] [k] 0x0fe07978
libc-2.11.2.so [k] _IO_vfscanf
1.60% top libc-2.11.2.so [k] _IO_vfscanf
[kernel.kallsyms] [k] .do_task_stat
1.20% top [kernel.kallsyms] [k] .do_task_stat
[kernel.kallsyms] [k] .do_task_stat
1.02% top libc-2.11.2.so [k] vfprintf
libc-2.11.2.so [k] vfprintf
0.92% top top [k] _init
[unknown] [k] 0x0fe037f4
Anshuman Khandual (5):
powerpc, perf: Add new BHRB related instructions on POWER8
powerpc, perf: Add basic assembly code to read BHRB entries on POWER8
powerpc, perf: Add new BHRB related generic functions, data and flags
powerpc, perf: Define BHRB generic functions, data and flags for POWER8
powerpc, perf: Enable branch stack sampling framework support with BHRB
arch/powerpc/include/asm/perf_event_server.h | 6 ++
arch/powerpc/include/asm/ppc-opcode.h | 7 ++
arch/powerpc/perf/Makefile | 2 +-
arch/powerpc/perf/bhrb.S | 34 ++++++++++
arch/powerpc/perf/core-book3s.c | 96 +++++++++++++++++++++++++++-
arch/powerpc/perf/perf_event_bhrb.c | 75 ++++++++++++++++++++++
arch/powerpc/perf/power8-pmu.c | 57 ++++++++++++++++-
7 files changed, 272 insertions(+), 5 deletions(-)
create mode 100644 arch/powerpc/perf/bhrb.S
create mode 100644 arch/powerpc/perf/perf_event_bhrb.c
--
1.7.11.7
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