The synthesize benchmark, run on a single process and thread, shows
perf_event__synthesize_mmap_events as the hottest function with fgets
and sscanf taking the majority of execution time.
fscanf performs similarly well. Replace the scanf call with manual
reading of each field of the /proc/pid/maps line, and remove some
unnecessary buffering.
This change also addresses potential, but unlikely, buffer overruns for
the string values read by scanf.
Performance before is:
$ sudo perf bench internals synthesize -m 16 -M 16 -s -t
\# Running 'internals/synthesize' benchmark:
Computing performance of single threaded perf event synthesis by
synthesizing events on the perf process itself:
Average synthesis took: 102.810 usec (+- 0.027 usec)
Average num. events: 17.000 (+- 0.000)
Average time per event 6.048 usec
Average data synthesis took: 106.325 usec (+- 0.018 usec)
Average num. events: 89.000 (+- 0.000)
Average time per event 1.195 usec
Computing performance of multi threaded perf event synthesis by
synthesizing events on CPU 0:
Number of synthesis threads: 16
Average synthesis took: 68103.100 usec (+- 441.234 usec)
Average num. events: 30703.000 (+- 0.730)
Average time per event 2.218 usec
And after is:
$ sudo perf bench internals synthesize -m 16 -M 16 -s -t
\# Running 'internals/synthesize' benchmark:
Computing performance of single threaded perf event synthesis by
synthesizing events on the perf process itself:
Average synthesis took: 50.388 usec (+- 0.031 usec)
Average num. events: 17.000 (+- 0.000)
Average time per event 2.964 usec
Average data synthesis took: 52.693 usec (+- 0.020 usec)
Average num. events: 89.000 (+- 0.000)
Average time per event 0.592 usec
Computing performance of multi threaded perf event synthesis by
synthesizing events on CPU 0:
Number of synthesis threads: 16
Average synthesis took: 45022.400 usec (+- 552.740 usec)
Average num. events: 30624.200 (+- 10.037)
Average time per event 1.470 usec
On a Intel Xeon 6154 compiling with Debian gcc 9.2.1.
Committer testing:
On a AMD Ryzen 5 3600X 6-Core Processor:
Before:
# perf bench internals synthesize --min-threads 12 --max-threads 12 --st --mt
# Running 'internals/synthesize' benchmark:
Computing performance of single threaded perf event synthesis by
synthesizing events on the perf process itself:
Average synthesis took: 267.491 usec (+- 0.176 usec)
Average num. events: 56.000 (+- 0.000)
Average time per event 4.777 usec
Average data synthesis took: 277.257 usec (+- 0.169 usec)
Average num. events: 287.000 (+- 0.000)
Average time per event 0.966 usec
Computing performance of multi threaded perf event synthesis by
synthesizing events on CPU 0:
Number of synthesis threads: 12
Average synthesis took: 81599.500 usec (+- 346.315 usec)
Average num. events: 36096.100 (+- 2.523)
Average time per event 2.261 usec
#
After:
# perf bench internals synthesize --min-threads 12 --max-threads 12 --st --mt
# Running 'internals/synthesize' benchmark:
Computing performance of single threaded perf event synthesis by
synthesizing events on the perf process itself:
Average synthesis took: 110.125 usec (+- 0.080 usec)
Average num. events: 56.000 (+- 0.000)
Average time per event 1.967 usec
Average data synthesis took: 118.518 usec (+- 0.057 usec)
Average num. events: 287.000 (+- 0.000)
Average time per event 0.413 usec
Computing performance of multi threaded perf event synthesis by
synthesizing events on CPU 0:
Number of synthesis threads: 12
Average synthesis took: 43490.700 usec (+- 284.527 usec)
Average num. events: 37028.500 (+- 0.563)
Average time per event 1.175 usec
#
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrey Zhizhikin <andrey.z@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lore.kernel.org/lkml/20200415054050.31645-4-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When mmap2 events are synthesized the ino_generation field isn't being
set leading to uninitialized memory being compared.
Caught with clang's -fsanitize=memory:
==124733==WARNING: MemorySanitizer: use-of-uninitialized-value
#0 0x55a96a6a65cc in __dso_id__cmp tools/perf/util/dsos.c:23:6
#1 0x55a96a6a81d5 in dso_id__cmp tools/perf/util/dsos.c:38:9
#2 0x55a96a6a717f in __dso__cmp_long_name tools/perf/util/dsos.c:74:15
#3 0x55a96a6a6c4c in __dsos__findnew_link_by_longname_id tools/perf/util/dsos.c:106:12
#4 0x55a96a6a851e in __dsos__findnew_by_longname_id tools/perf/util/dsos.c:178:9
#5 0x55a96a6a7798 in __dsos__find_id tools/perf/util/dsos.c:191:9
#6 0x55a96a6a7b57 in __dsos__findnew_id tools/perf/util/dsos.c:251:20
#7 0x55a96a6a7a57 in dsos__findnew_id tools/perf/util/dsos.c:259:17
#8 0x55a96a7776ae in machine__findnew_dso_id tools/perf/util/machine.c:2709:9
#9 0x55a96a77dfcf in map__new tools/perf/util/map.c:193:10
#10 0x55a96a77240a in machine__process_mmap2_event tools/perf/util/machine.c:1670:8
#11 0x55a96a7741a3 in machine__process_event tools/perf/util/machine.c:1882:9
#12 0x55a96a6aee39 in perf_event__process tools/perf/util/event.c:454:9
#13 0x55a96a87d633 in perf_tool__process_synth_event tools/perf/util/synthetic-events.c:63:9
#14 0x55a96a87f131 in perf_event__synthesize_mmap_events tools/perf/util/synthetic-events.c:403:7
#15 0x55a96a8815d6 in __event__synthesize_thread tools/perf/util/synthetic-events.c:548:9
#16 0x55a96a882bff in __perf_event__synthesize_threads tools/perf/util/synthetic-events.c:681:3
#17 0x55a96a881ec2 in perf_event__synthesize_threads tools/perf/util/synthetic-events.c:750:9
#18 0x55a96a562b26 in synth_all tools/perf/tests/mmap-thread-lookup.c:136:9
#19 0x55a96a5623b1 in mmap_events tools/perf/tests/mmap-thread-lookup.c:174:8
#20 0x55a96a561fa0 in test__mmap_thread_lookup tools/perf/tests/mmap-thread-lookup.c:230:2
#21 0x55a96a52c182 in run_test tools/perf/tests/builtin-test.c:378:9
#22 0x55a96a52afc1 in test_and_print tools/perf/tests/builtin-test.c:408:9
#23 0x55a96a52966e in __cmd_test tools/perf/tests/builtin-test.c:603:4
#24 0x55a96a52855d in cmd_test tools/perf/tests/builtin-test.c:747:9
#25 0x55a96a2844d4 in run_builtin tools/perf/perf.c:312:11
#26 0x55a96a282bd0 in handle_internal_command tools/perf/perf.c:364:8
#27 0x55a96a284097 in run_argv tools/perf/perf.c:408:2
#28 0x55a96a282223 in main tools/perf/perf.c:538:3
Uninitialized value was stored to memory at
#1 0x55a96a6a18f7 in dso__new_id tools/perf/util/dso.c:1230:14
#2 0x55a96a6a78ee in __dsos__addnew_id tools/perf/util/dsos.c:233:20
#3 0x55a96a6a7bcc in __dsos__findnew_id tools/perf/util/dsos.c:252:21
#4 0x55a96a6a7a57 in dsos__findnew_id tools/perf/util/dsos.c:259:17
#5 0x55a96a7776ae in machine__findnew_dso_id tools/perf/util/machine.c:2709:9
#6 0x55a96a77dfcf in map__new tools/perf/util/map.c:193:10
#7 0x55a96a77240a in machine__process_mmap2_event tools/perf/util/machine.c:1670:8
#8 0x55a96a7741a3 in machine__process_event tools/perf/util/machine.c:1882:9
#9 0x55a96a6aee39 in perf_event__process tools/perf/util/event.c:454:9
#10 0x55a96a87d633 in perf_tool__process_synth_event tools/perf/util/synthetic-events.c:63:9
#11 0x55a96a87f131 in perf_event__synthesize_mmap_events tools/perf/util/synthetic-events.c:403:7
#12 0x55a96a8815d6 in __event__synthesize_thread tools/perf/util/synthetic-events.c:548:9
#13 0x55a96a882bff in __perf_event__synthesize_threads tools/perf/util/synthetic-events.c:681:3
#14 0x55a96a881ec2 in perf_event__synthesize_threads tools/perf/util/synthetic-events.c:750:9
#15 0x55a96a562b26 in synth_all tools/perf/tests/mmap-thread-lookup.c:136:9
#16 0x55a96a5623b1 in mmap_events tools/perf/tests/mmap-thread-lookup.c:174:8
#17 0x55a96a561fa0 in test__mmap_thread_lookup tools/perf/tests/mmap-thread-lookup.c:230:2
#18 0x55a96a52c182 in run_test tools/perf/tests/builtin-test.c:378:9
#19 0x55a96a52afc1 in test_and_print tools/perf/tests/builtin-test.c:408:9
Uninitialized value was stored to memory at
#0 0x55a96a7725af in machine__process_mmap2_event tools/perf/util/machine.c:1646:25
#1 0x55a96a7741a3 in machine__process_event tools/perf/util/machine.c:1882:9
#2 0x55a96a6aee39 in perf_event__process tools/perf/util/event.c:454:9
#3 0x55a96a87d633 in perf_tool__process_synth_event tools/perf/util/synthetic-events.c:63:9
#4 0x55a96a87f131 in perf_event__synthesize_mmap_events tools/perf/util/synthetic-events.c:403:7
#5 0x55a96a8815d6 in __event__synthesize_thread tools/perf/util/synthetic-events.c:548:9
#6 0x55a96a882bff in __perf_event__synthesize_threads tools/perf/util/synthetic-events.c:681:3
#7 0x55a96a881ec2 in perf_event__synthesize_threads tools/perf/util/synthetic-events.c:750:9
#8 0x55a96a562b26 in synth_all tools/perf/tests/mmap-thread-lookup.c:136:9
#9 0x55a96a5623b1 in mmap_events tools/perf/tests/mmap-thread-lookup.c:174:8
#10 0x55a96a561fa0 in test__mmap_thread_lookup tools/perf/tests/mmap-thread-lookup.c:230:2
#11 0x55a96a52c182 in run_test tools/perf/tests/builtin-test.c:378:9
#12 0x55a96a52afc1 in test_and_print tools/perf/tests/builtin-test.c:408:9
#13 0x55a96a52966e in __cmd_test tools/perf/tests/builtin-test.c:603:4
#14 0x55a96a52855d in cmd_test tools/perf/tests/builtin-test.c:747:9
#15 0x55a96a2844d4 in run_builtin tools/perf/perf.c:312:11
#16 0x55a96a282bd0 in handle_internal_command tools/perf/perf.c:364:8
#17 0x55a96a284097 in run_argv tools/perf/perf.c:408:2
#18 0x55a96a282223 in main tools/perf/perf.c:538:3
Uninitialized value was created by a heap allocation
#0 0x55a96a22f60d in malloc llvm/llvm-project/compiler-rt/lib/msan/msan_interceptors.cpp:925:3
#1 0x55a96a882948 in __perf_event__synthesize_threads tools/perf/util/synthetic-events.c:655:15
#2 0x55a96a881ec2 in perf_event__synthesize_threads tools/perf/util/synthetic-events.c:750:9
#3 0x55a96a562b26 in synth_all tools/perf/tests/mmap-thread-lookup.c:136:9
#4 0x55a96a5623b1 in mmap_events tools/perf/tests/mmap-thread-lookup.c:174:8
#5 0x55a96a561fa0 in test__mmap_thread_lookup tools/perf/tests/mmap-thread-lookup.c:230:2
#6 0x55a96a52c182 in run_test tools/perf/tests/builtin-test.c:378:9
#7 0x55a96a52afc1 in test_and_print tools/perf/tests/builtin-test.c:408:9
#8 0x55a96a52966e in __cmd_test tools/perf/tests/builtin-test.c:603:4
#9 0x55a96a52855d in cmd_test tools/perf/tests/builtin-test.c:747:9
#10 0x55a96a2844d4 in run_builtin tools/perf/perf.c:312:11
#11 0x55a96a282bd0 in handle_internal_command tools/perf/perf.c:364:8
#12 0x55a96a284097 in run_argv tools/perf/perf.c:408:2
#13 0x55a96a282223 in main tools/perf/perf.c:538:3
SUMMARY: MemorySanitizer: use-of-uninitialized-value tools/perf/util/dsos.c:23:6 in __dso_id__cmp
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: clang-built-linux@googlegroups.com
Link: http://lore.kernel.org/lkml/20200313053129.131264-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The low level index of raw branch records for the most recent branch can
be recorded in a sample with PERF_SAMPLE_BRANCH_HW_INDEX
branch_sample_type. Extend struct branch_stack to support it.
However, if the PERF_SAMPLE_BRANCH_HW_INDEX is not applied, only nr and
entries[] will be output by kernel. The pointer of entries[] could be
wrong, since the output format is different with new struct
branch_stack. Add a variable no_hw_idx in struct perf_sample to
indicate whether the hw_idx is output. Add get_branch_entry() to return
corresponding pointer of entries[0].
To make dummy branch sample consistent as new branch sample, add hw_idx
in struct dummy_branch_stack for cs-etm and intel-pt.
Apply the new struct branch_stack for synthetic events as well.
Extend test case sample-parsing to support new struct branch_stack.
Committer notes:
Renamed get_branch_entries() to perf_sample__branch_entries() to have
proper namespacing and pave the way for this to be moved to libperf,
eventually.
Add 'static' to that inline as it is in a header.
Add 'hw_idx' to 'struct dummy_branch_stack' in cs-etm.c to fix the build
on arm64.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pavel Gerasimov <pavel.gerasimov@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vitaly Slobodskoy <vitaly.slobodskoy@intel.com>
Link: http://lore.kernel.org/lkml/20200228163011.19358-2-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
And pick the shortest name: 'struct maps'.
The split existed because we used to have two groups of maps, one for
functions and one for variables, but that only complicated things,
sometimes we needed to figure out what was at some address and then had
to first try it on the functions group and if that failed, fall back to
the variables one.
That split is long gone, so for quite a while we had only one struct
maps per struct map_groups, simplify things by combining those structs.
First patch is the minimum needed to merge both, follow up patches will
rename 'thread->mg' to 'thread->maps', etc.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-hom6639ro7020o708trhxh59@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add kernel AUX area sampling definitions, which brings perf_event.h into
line with the kernel version.
New sample type PERF_SAMPLE_AUX requests a sample of the AUX area
buffer. New perf_event_attr member 'aux_sample_size' specifies the
desired size of the sample.
Also add support for parsing samples containing AUX area data i.e.
PERF_SAMPLE_AUX.
Committer notes:
I squashed the first two patches in this series to avoid breaking
automatic bisection, i.e. after applying only the original first patch
in this series we would have:
# perf test -v parsing
26: Sample parsing :
--- start ---
test child forked, pid 17018
sample format has changed, some new PERF_SAMPLE_ bit was introduced - test needs updating
test child finished with -1
---- end ----
Sample parsing: FAILED!
#
With the two paches combined:
# perf test parsing
26: Sample parsing : Ok
#
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20191115124225.5247-3-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
