| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Thu, 29 Jan 2015 17:06:41 +0900 From: Namhyung Kim <namhyung@...nel.org> To: Arnaldo Carvalho de Melo <acme@...nel.org> Cc: Ingo Molnar <mingo@...nel.org>, Peter Zijlstra <a.p.zijlstra@...llo.nl>, Jiri Olsa <jolsa@...hat.com>, LKML <linux-kernel@...r.kernel.org>, David Ahern <dsahern@...il.com>, Adrian Hunter <adrian.hunter@...el.com>, Andi Kleen <andi@...stfloor.org>, Stephane Eranian <eranian@...gle.com>, Frederic Weisbecker <fweisbec@...il.com> Subject: [RFC/PATCHSET 00/42] perf tools: Speed-up perf report by using multi thread (v2) Hello, This patchset converts perf report to use multiple threads in order to speed up the processing on large data files. I can see a minimum ~30% of speedup with this change. The code is still experimental and contains many rough edges. But I'd like to share and give some feedbacks. The main change in this version is using single data file with an index table rather than using multiple files. It seems that single thread performance was improved by this than previous version but multi thread performance remains almost same. The perf report processes (sample) events like below: 1. preprocess sample to get matching thread/dso/symbol info 2. insert it to hists rbtree (with callchain tree) based on the info 3. optionally collapse hist entries that match given sort key(s) 4. resort hist entries (by overhead) for output 5. display the hist entries The stage 1 is a preprocessing and mostly act like a read-only operation in that it doesn't change a machine state during the sample processing. Meta events like fork, comm and mmap can change the machine/thread state but symbols can be loaded during the processing (stage 2). The stage 2 consumes most of the time especially with callchains and --children option is enabled. And this work can be easily patitioned as each sample is independent to others. But the resulting hists must be combined/collapsed to a single global hists before going to further steps. The stage 3 is optional and only needed by certain sort keys - but with stage 2 paralellized, it needs to be done always. The stage 4 and 5 works on whole hists so must be done serially. So my approach is like this: Partially do stage 1 first - but only for meta events that changes machine state. To do this I add a dummy tracking event to perf record and make it collect such meta events only. They are saved as normal data and processed before sample events at perf report time. This also requires to handle multiple sample data concurrently and to find a corresponding machine state when processing samples. On a large profiling session, many tasks were created and exited so pid might be recycled (even more than once!). To deal with it, I managed to have thread, map_groups and comm in time sorted. The only remaining thing is symbol loading as it's done lazily when sample requires it. With that being done, the stage 2 can be done by multiple threads. I also save each sample data (per-cpu or per-thread) in separate files during record and then merge them into a single data file with an index table. On perf report time, each region of sample data will be processed by each thread. And symbol loading is protected by a mutex lock. For DWARF post-unwinding, dso cache data also needs to be protected by a lock and this caused a huge contention. I made it to search the rbtree speculatively first and then, if it didn't find one, search it again under the dso lock. Please take a look at it if it's acceptable. The patch 1-4 are independent fixes and cleans. The patch 5-14 are to support indexing for data file. With --index option, perf record will create a intermediate directory and then save meta events and sample data to separate files. And finally it'll build an index table and concatenate the data files. The patch 15-26 are to manage machine and thread state using timestamp so that it can be searched when processing samples. The patch 27-40 are to implement parallel report. And finally I implemented 'perf data index' command to build an index table for a given data file. This patchset didn't change perf record to use multi-thread. But I think it can be easily done later if needed. Note that output has a slight difference to original version when compared using indexed data file. But they're mostly unresolved symbols for callchains. Here is the result: This is just elapsed time measured by 'perf stat -r 5'. The data file was recorded during kernel build with fp callchain and size is 2.1GB. The machine has 6 core with hyper-threading enabled and I got a similar result on my laptop too. perf report --children --no-children + --call-graph none ------------- ------------- ------------------- current 285.708340593 94.317412961 36.707232978 with index 253.322717665 77.079748639 24.892021523 + --multi-thread 174.037760271 44.717308080 8.300466711 This result is with 7.7GB data file using libunwind for callchain. perf report --children --no-children + --call-graph none ------------- ------------- ------------------- current 247.070444039 196.393820003 5.068489333 with index 149.456483830 108.917644447 3.642109876 + --multi-thread 43.990095636 28.342798882 1.829218561 I guess the speedup of indexed data file came from skipping ordered event layer. This result is with same file but using libdw for callchain unwind. perf report --children --no-children + --call-graph none ------------- ------------- ------------------- current 465.661321115 496.153153039 4.629841428 with index 445.712762188 462.146612217 3.535147499 + --multi-thread 215.264706814 29.279996335 1.938137940 On my archlinux system, callchain unwind using libdw is much slower than libunwind. I'm using elfutils version 0.160. Also I don't know why --children takes less time than --no-children. Anyway we can see the --multi-thread performance is much better for each case. You can get it from 'perf/threaded-v2' branch on my tree at: git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git Please take a look and play with it. Any comments are welcome! :) Thanks, Namhyung Jiri Olsa (1): perf tools: Add new perf data command Namhyung Kim (41): perf tools: Support to read compressed module from build-id cache perf tools: Do not use __perf_session__process_events() directly perf record: Show precise number of samples perf header: Set header version correctly perf tools: Set attr.task bit for a tracking event perf tools: Use a software dummy event to track task/mmap events perf tools: Use perf_data_file__fd() consistently perf tools: Add rm_rf() utility function perf tools: Introduce copyfile_offset() function perf tools: Create separate mmap for dummy tracking event perf tools: Introduce perf_evlist__mmap_track() perf tools: Add HEADER_DATA_INDEX feature perf tools: Handle indexed data file properly perf record: Add --index option for building index table perf report: Skip dummy tracking event perf tools: Pass session arg to perf_event__preprocess_sample() perf script: Pass session arg to ->process_event callback perf tools: Introduce thread__comm_time() helpers perf tools: Add a test case for thread comm handling perf tools: Use thread__comm_time() when adding hist entries perf tools: Convert dead thread list into rbtree perf tools: Introduce machine__find*_thread_time() perf tools: Add a test case for timed thread handling perf tools: Maintain map groups list in a leader thread perf tools: Introduce thread__find_addr_location_time() and friends perf tools: Add a test case for timed map groups handling perf tools: Protect dso symbol loading using a mutex perf tools: Protect dso cache tree using dso->lock perf tools: Protect dso cache fd with a mutex perf session: Pass struct events stats to event processing functions perf hists: Pass hists struct to hist_entry_iter functions perf tools: Move BUILD_ID_SIZE definition to perf.h perf report: Parallelize perf report using multi-thread perf tools: Add missing_threads rb tree perf record: Synthesize COMM event for a command line workload perf tools: Fix progress ui to support multi thread perf report: Add --multi-thread option and config item perf session: Handle index files generally perf tools: Convert lseek + read to pread perf callchain: Save eh/debug frame offset for dwarf unwind perf data: Implement 'index' subcommand tools/perf/Documentation/perf-data.txt | 44 +++ tools/perf/Documentation/perf-record.txt | 4 + tools/perf/Documentation/perf-report.txt | 3 + tools/perf/Makefile.perf | 4 + tools/perf/builtin-annotate.c | 8 +- tools/perf/builtin-data.c | 428 +++++++++++++++++++++ tools/perf/builtin-diff.c | 21 +- tools/perf/builtin-inject.c | 5 +- tools/perf/builtin-mem.c | 6 +- tools/perf/builtin-record.c | 261 +++++++++++-- tools/perf/builtin-report.c | 74 +++- tools/perf/builtin-script.c | 54 ++- tools/perf/builtin-timechart.c | 10 +- tools/perf/builtin-top.c | 7 +- tools/perf/builtin.h | 1 + tools/perf/command-list.txt | 1 + tools/perf/perf.c | 1 + tools/perf/perf.h | 2 + tools/perf/tests/builtin-test.c | 12 + tools/perf/tests/dso-data.c | 5 + tools/perf/tests/dwarf-unwind.c | 8 +- tools/perf/tests/hists_common.c | 3 +- tools/perf/tests/hists_cumulate.c | 6 +- tools/perf/tests/hists_filter.c | 5 +- tools/perf/tests/hists_link.c | 10 +- tools/perf/tests/hists_output.c | 6 +- tools/perf/tests/tests.h | 3 + tools/perf/tests/thread-comm.c | 47 +++ tools/perf/tests/thread-lookup-time.c | 180 +++++++++ tools/perf/tests/thread-mg-share.c | 7 +- tools/perf/tests/thread-mg-time.c | 88 +++++ tools/perf/ui/browsers/hists.c | 30 +- tools/perf/ui/gtk/hists.c | 3 + tools/perf/util/build-id.c | 9 +- tools/perf/util/build-id.h | 2 - tools/perf/util/db-export.c | 6 +- tools/perf/util/db-export.h | 4 +- tools/perf/util/dso.c | 159 +++++--- tools/perf/util/dso.h | 3 + tools/perf/util/event.c | 106 ++++- tools/perf/util/event.h | 13 +- tools/perf/util/evlist.c | 161 ++++++-- tools/perf/util/evlist.h | 22 +- tools/perf/util/evsel.c | 1 + tools/perf/util/evsel.h | 15 + tools/perf/util/header.c | 63 ++- tools/perf/util/header.h | 3 + tools/perf/util/hist.c | 121 ++++-- tools/perf/util/hist.h | 12 +- tools/perf/util/machine.c | 258 +++++++++++-- tools/perf/util/machine.h | 12 +- tools/perf/util/map.c | 1 + tools/perf/util/map.h | 2 + tools/perf/util/ordered-events.c | 4 +- .../perf/util/scripting-engines/trace-event-perl.c | 3 +- .../util/scripting-engines/trace-event-python.c | 5 +- tools/perf/util/session.c | 356 ++++++++++++++--- tools/perf/util/session.h | 11 +- tools/perf/util/symbol-elf.c | 13 +- tools/perf/util/symbol.c | 34 +- tools/perf/util/thread.c | 139 ++++++- tools/perf/util/thread.h | 28 +- tools/perf/util/tool.h | 14 + tools/perf/util/trace-event-scripting.c | 3 +- tools/perf/util/trace-event.h | 3 +- tools/perf/util/unwind-libdw.c | 11 +- tools/perf/util/unwind-libunwind.c | 49 ++- tools/perf/util/util.c | 81 +++- tools/perf/util/util.h | 2 + 69 files changed, 2662 insertions(+), 414 deletions(-) create mode 100644 tools/perf/Documentation/perf-data.txt create mode 100644 tools/perf/builtin-data.c create mode 100644 tools/perf/tests/thread-comm.c create mode 100644 tools/perf/tests/thread-lookup-time.c create mode 100644 tools/perf/tests/thread-mg-time.c -- 2.2.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists