Jiri,
On 23 May 2014 10:13, Jiri Olsa <jo...@redhat.com> wrote: > ping ;-) This looks a ping to yourself ;-) Here are the results on ARMv7: - libunwind: between -29% in execution time for light load (i.e. using not-so-deep backtraces from the stress app.) and -49% for deep backtrace (the 'stress_bt' app.), - libdw: no significant improvement (0-2% improvement). Cf. https://wiki.linaro.org/LEG/Engineering/TOOLS/perf-callstack-unwinding#Speed_improvement for more details. FWIW: Acked-by: Jean Pihet <jean.pi...@linaro.org> Regards, Jean > > thanks, > jirka > > On Thu, May 15, 2014 at 07:23:21PM +0200, Jiri Olsa wrote: >> hi, >> trying to speedup DWARF unwind report code by factoring >> related code: >> - caching sample's registers access >> - keep dso data file descriptor open for the >> life of the dso object >> - replace dso cache code by mapping dso data file >> directly for the life of the dso object >> >> The speedup is mainly for libunwind unwind. The libdw will benefit >> mainly from cached registers access, because it handles dso data >> accesses by itself.. and anyway it's still faster ;-). >> >> v2 changes: >> - adding limit for open dso objects with sort of LRU >> mechanism to pick up and close dso objects if we >> are over the limit >> - file mmaping changes are omitted, because I couldn't prove >> the improvement exactly, will resubmit later >> - added dso close logic in case of no memory >> - added tests >> >> On 10GB perf data file with dwarf unwind data I've got >> around 30% speed up. >> >> Also reachable in here: >> git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git >> perf/core_unwind_speedup >> >> thanks, >> jirka >> >> Cc: Arnaldo Carvalho de Melo <a...@kernel.org> >> Cc: Corey Ashford <cjash...@linux.vnet.ibm.com> >> Cc: David Ahern <dsah...@gmail.com> >> Cc: Frederic Weisbecker <fweis...@gmail.com> >> Cc: Ingo Molnar <mi...@kernel.org> >> Cc: Jean Pihet <jean.pi...@linaro.org> >> Cc: Namhyung Kim <namhy...@kernel.org> >> Cc: Paul Mackerras <pau...@samba.org> >> Cc: Peter Zijlstra <a.p.zijls...@chello.nl> >> Signed-off-by: Jiri Olsa <jo...@kernel.org> >> --- >> Jiri Olsa (14): >> perf tools: Cache register accesses for unwind processing >> perf tools: Separate dso data related variables >> perf tools: Add data_fd into dso object >> perf tools: Add global list of opened dso objects >> perf tools: Add global count of opened dso objects >> perf tools: Cache dso data file descriptor >> perf tools: Add file size check and factor dso__data_read_offset >> perf tools: Allow to close dso fd in case of open failure >> perf tools: Add dso__data_* interface descriptons >> perf tests: Spawn child for each test >> perf tests: Allow reuse of test_file function >> perf tests: Add test interface for dso data fd limit >> perf tests: Add test for caching dso file descriptors >> perf tests: Add test for closing dso objects on EMFILE error >> >> tools/perf/tests/builtin-test.c | 42 ++++++++++++++- >> tools/perf/tests/dso-data.c | 256 >> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-- >> tools/perf/tests/tests.h | 2 + >> tools/perf/util/dso.c | 274 >> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--------- >> tools/perf/util/dso.h | 56 +++++++++++++++++++- >> tools/perf/util/event.h | 5 ++ >> tools/perf/util/perf_regs.c | 10 +++- >> tools/perf/util/perf_regs.h | 4 +- >> tools/perf/util/unwind-libunwind.c | 4 +- >> 9 files changed, 617 insertions(+), 36 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
