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Date: Wed, 24 Dec 2014 16:14:56 +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>, Stephane Eranian <eranian@...gle.com>, Adrian Hunter <adrian.hunter@...el.com>, Andi Kleen <andi@...stfloor.org>, Frederic Weisbecker <fweisbec@...il.com> Subject: [RFC/PATCHSET 00/37] perf tools: Speed-up perf report by using multi thread (v1) 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 40% of speedup with this change. The code is still experimental, little bit outdated and contains many rough edges. But I'd like to share and give some feedbacks. 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 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 anyway. 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 in a separate file (perf.header) and processed before sample events at perf report time. This also requires to handle multiple files 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. On perf report time, each file 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 causes a huge contention. I just added a front cache that can be accessed without the lock but this should be improved IMHO. The patch 1-10 are to support multi-file data recording. With -M/--multi option, perf record will create a directory (named 'perf.data.dir' by default - but maybe renamed 'perf.data' for transparent conversion later) and save meta events to perf.header file and sample events to perf.data.<n> file). It'd be better considering file format change Jiri suggested [1]. The patch 11-20 are to manage machine and thread state using timestamp so that it can be searched when processing samples. The patch 21-35 are to implement parallel report. And finally I implemented 'perf data split' command to convert a single data file into a multi-file format. 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 splitted data file. But they're mostly unresolved symbols for callchains. Here is the result: This is just elapsed (real) time measured by shell 'time' function. 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. time perf report --children --no-children + --call-graph none ---------- ------------- ------------------- current 4m43.260s 1m32.779s 0m35.866s patched 4m43.710s 1m29.695s 0m33.995s --multi-thread 2m46.265s 0m45.486s 0m7.570s This result is with 7.7GB data file using libunwind for callchain. time perf report --children --no-children + --call-graph none ---------- ------------- ------------------- current 3m51.762s 3m10.451s 0m4.695s patched 2m26.030s 1m49.846s 0m4.105s --multi-thread 0m49.217s 0m35.106s 0m1.457s Note that the single thread performance improvement in patched version is due to changes in the patch 33-35. This result is with same file but using libdw for callchain unwind. time perf report --children --no-children + --call-graph none ---------- ------------- ------------------- current 10m22.472s 11m42.290s 0m4.758s patched 10m10.625s 11m45.480s 0m4.162s --multi-thread 3m47.332s 3m35.235s 0m1.755s 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-v1' 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 [1] https://lkml.org/lkml/2013/9/1/20 Jiri Olsa (1): perf tools: Add new perf data command Namhyung Kim (36): perf tools: Set attr.task bit for a tracking event perf record: Use a software dummy event to track task/mmap events perf tools: Use perf_data_file__fd() consistently perf tools: Add multi file interface to perf_data_file perf tools: Create separate mmap for dummy tracking event perf tools: Introduce perf_evlist__mmap_multi() perf tools: Do not use __perf_session__process_events() directly perf tools: Handle multi-file session properly perf record: Add -M/--multi option for multi file recording perf report: Skip dummy tracking event 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: Remove thread when map groups initialization failed 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 top: Always creates thread in the current task tree. perf tools: Fix progress ui to support multi thread perf record: Show total size of multi file data perf report: Add --multi-thread option and config item perf tools: Add front cache for dso data access perf tools: Convert lseek + read to pread perf callchain: Save eh/debug frame offset for dwarf unwind perf data: Implement 'split' subcommand tools/perf/Documentation/perf-data.txt | 43 ++++ tools/perf/Documentation/perf-record.txt | 5 + tools/perf/Documentation/perf-report.txt | 3 + tools/perf/Makefile.perf | 4 + tools/perf/builtin-annotate.c | 5 +- tools/perf/builtin-data.c | 298 ++++++++++++++++++++++++++ tools/perf/builtin-diff.c | 8 +- tools/perf/builtin-inject.c | 9 +- tools/perf/builtin-record.c | 65 ++++-- tools/perf/builtin-report.c | 107 ++++++++-- tools/perf/builtin-script.c | 5 +- tools/perf/builtin-top.c | 9 +- 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 | 10 +- tools/perf/tests/hists_common.c | 3 +- tools/perf/tests/hists_cumulate.c | 4 +- tools/perf/tests/hists_filter.c | 3 +- tools/perf/tests/hists_link.c | 6 +- tools/perf/tests/hists_output.c | 4 +- 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 | 10 +- tools/perf/ui/gtk/hists.c | 3 + tools/perf/util/build-id.c | 9 +- tools/perf/util/build-id.h | 2 - tools/perf/util/data.c | 188 ++++++++++++++++- tools/perf/util/data.h | 17 ++ tools/perf/util/dso.c | 192 ++++++++++++----- tools/perf/util/dso.h | 5 + tools/perf/util/event.c | 85 ++++++-- tools/perf/util/event.h | 6 +- tools/perf/util/evlist.c | 151 ++++++++++++-- tools/perf/util/evlist.h | 22 +- tools/perf/util/evsel.c | 1 + tools/perf/util/evsel.h | 15 ++ tools/perf/util/hist.c | 121 +++++++---- tools/perf/util/hist.h | 12 +- tools/perf/util/machine.c | 251 +++++++++++++++++++--- 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 +- tools/perf/util/session.c | 347 ++++++++++++++++++++++++++----- tools/perf/util/session.h | 8 +- tools/perf/util/symbol.c | 34 ++- tools/perf/util/thread.c | 140 ++++++++++++- tools/perf/util/thread.h | 28 ++- tools/perf/util/tool.h | 17 ++ tools/perf/util/unwind-libdw.c | 11 +- tools/perf/util/unwind-libunwind.c | 49 +++-- tools/perf/util/util.c | 43 ++++ tools/perf/util/util.h | 1 + 60 files changed, 2381 insertions(+), 344 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 -- 2.1.3 -- 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/
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