Re: [PATCH 00/16] perf tools: Add libdw DWARF unwind support

From: Jean Pihet
Date: Fri Jan 17 2014 - 07:28:03 EST


Hi Jiri,

Let me start on it next week. Is that OK?

Thx for the reminder, I had not entirely forgotten it though ;p

Regards,
Jean

On 17 January 2014 13:24, Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
> ping ;-)
>
> thanks,
> jirka
>
> On Tue, Jan 07, 2014 at 01:47:17PM +0100, Jiri Olsa wrote:
>> hi,
>> adding libdw DWARF unwind support, which is part of just released
>> elfutils package 0.158.
>>
>> We can now compile perf to have either libunwind DWARF unwind,
>> (which is still default) or the new one libdw unwind.
>>
>> Examples:
>> - compile in libdw unwinder if present:
>> $ make NO_LIBUNWIND=1
>>
>> - compile in libdw (with libdw installation directory) unwinder if present:
>> $ make LIBDW_DIR=/opt/elfutils/ NO_LIBUNWIND=1
>>
>> - disable post dwarf unwind completely:
>> $ make NO_LIBUNWIND=1 NO_LIBDW_DWARF_UNWIND=1
>>
>> Performance wise the libdw unwinder seems to be faster.
>> Following results are from 2GB perf.data file with 249156
>> samples:
>>
>> The libdw unwind perf:
>> $ time perf report -i ~/perf.data > perf.data.ldw
>>
>> real 0m35.746s
>> user 0m24.211s
>> sys 0m11.214s
>>
>> The libunwind unwind perf:
>> $ time perf report -i ~/perf.data > perf.data.unw
>>
>> real 1m41.149s
>> user 1m9.694s
>> sys 0m30.595s
>>
>> In example above I've got 2206 differences (perf.data.ldw and
>> perf.data.unw files) in the callchains output out of the 249156
>> samples which is below 1%. Together with some other tips for speed
>> increase it's on my TODO list for future.
>>
>> Git tree:
>> https://git.kernel.org/cgit/linux/kernel/git/jolsa/perf.git/
>> perf/core_libdw_unwind
>>
>> Kudos to Jan Kratochvil for helping me with the new interface.
>>
>> Jean,
>> I haven't tested on arm.. so not sure I broke anything there.
>> Any chance you could test for me, and maybe make the automated
>> test I added work there? ;-)
>>
>> thanks,
>> jirka
>>
>>
>> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
>> Cc: Corey Ashford <cjashfor@xxxxxxxxxxxxxxxxxx>
>> Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
>> Cc: Ingo Molnar <mingo@xxxxxxx>
>> Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
>> Cc: Paul Mackerras <paulus@xxxxxxxxx>
>> Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
>> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxxxxxxx>
>> Cc: David Ahern <dsahern@xxxxxxxxx>
>> Cc: Jan Kratochvil <jan.kratochvil@xxxxxxxxxx>
>> Cc: Jean Pihet <jean.pihet@xxxxxxxxxx>
>> ---
>> Jiri Olsa (16):
>> perf tools: Automate setup of FEATURE_CHECK_(C|LD)FLAGS-all variables
>> perf tools: Fix machine initialization
>> perf tools: Make perf_event__synthesize_mmap_events global
>> perf tests x86: Introduce perf_regs_load function
>> perf tests x86: Add dwarf unwind test
>> perf tools: Fix dwarf unwind max_stack processing
>> perf tools: Do not report zero address in unwind
>> perf tools: Add mask into struct regs_dump
>> perf tools: Separate libunwind code to special object
>> perf tools: Rename unwind__arch_reg_id into libunwind__arch_reg_id
>> perf tools: Introduce HAVE_DWARF_UNWIND_SUPPORT macro
>> perf tools: Separate perf_reg_value function in perf_regs object
>> perf tools: Add feature check for libdw dwarf unwind
>> perf tools: Add libdw DWARF post unwind support
>> perf tools: Setup default dwarf post unwinder
>> perf tests: Add NO_LIBDW_DWARF_UNWIND make test
>>
>> tools/perf/Makefile.perf | 19 ++++++-
>> tools/perf/arch/arm/Makefile | 2 +-
>> tools/perf/arch/arm/util/{unwind.c => unwind-libunwind.c} | 2 +-
>> tools/perf/arch/x86/Makefile | 9 +++-
>> tools/perf/arch/x86/include/perf_regs.h | 6 +++
>> tools/perf/arch/x86/tests/dwarf-unwind.c | 59 ++++++++++++++++++++
>> tools/perf/arch/x86/tests/regs_load.S | 92 ++++++++++++++++++++++++++++++++
>> tools/perf/arch/x86/util/unwind-libdw.c | 51 ++++++++++++++++++
>> tools/perf/arch/x86/util/{unwind.c => unwind-libunwind.c} | 4 +-
>> tools/perf/builtin-inject.c | 1 -
>> tools/perf/builtin-record.c | 10 ++--
>> tools/perf/config/Makefile | 94 +++++++++++++++++++++++---------
>> tools/perf/config/feature-checks/Makefile | 6 ++-
>> tools/perf/config/feature-checks/test-all.c | 5 ++
>> tools/perf/config/feature-checks/test-libdw-dwarf-unwind.c | 13 +++++
>> tools/perf/tests/builtin-test.c | 8 +++
>> tools/perf/tests/dwarf-unwind.c | 144 +++++++++++++++++++++++++++++++++++++++++++++++++
>> tools/perf/tests/make | 63 +++++++++++-----------
>> tools/perf/tests/sample-parsing.c | 17 +++---
>> tools/perf/tests/tests.h | 9 ++++
>> tools/perf/util/event.c | 12 ++---
>> tools/perf/util/event.h | 12 ++++-
>> tools/perf/util/evsel.c | 13 ++---
>> tools/perf/util/machine.c | 4 +-
>> tools/perf/util/perf_regs.c | 19 +++++++
>> tools/perf/util/perf_regs.h | 13 +++++
>> tools/perf/util/session.c | 5 +-
>> tools/perf/util/unwind-libdw.c | 210 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>> tools/perf/util/unwind-libdw.h | 21 ++++++++
>> tools/perf/util/{unwind.c => unwind-libunwind.c} | 50 ++++++-----------
>> tools/perf/util/unwind.h | 11 ++--
>> 31 files changed, 849 insertions(+), 135 deletions(-)
>> rename tools/perf/arch/arm/util/{unwind.c => unwind-libunwind.c} (95%)
>> create mode 100644 tools/perf/arch/x86/tests/dwarf-unwind.c
>> create mode 100644 tools/perf/arch/x86/tests/regs_load.S
>> create mode 100644 tools/perf/arch/x86/util/unwind-libdw.c
>> rename tools/perf/arch/x86/util/{unwind.c => unwind-libunwind.c} (95%)
>> create mode 100644 tools/perf/config/feature-checks/test-libdw-dwarf-unwind.c
>> create mode 100644 tools/perf/tests/dwarf-unwind.c
>> create mode 100644 tools/perf/util/perf_regs.c
>> create mode 100644 tools/perf/util/unwind-libdw.c
>> create mode 100644 tools/perf/util/unwind-libdw.h
>> rename tools/perf/util/{unwind.c => unwind-libunwind.c} (92%)
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