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 <[email protected]>
Cc: Corey Ashford <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jan Kratochvil <[email protected]>
Cc: Jean Pihet <[email protected]>
---
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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