linux-stable.git/tools/perf/Documentation, branch v6.4

perf lock contention: Update default map size to 16384

2023-04-07T00:52:27+00:00

The BPF hash map will align the map size to a power of 2.  So 10k would
be 16k anyway.  Let's have the actual size to avoid confusions.

Signed-off-by: Namhyung Kim 
Acked-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Hao Luo 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Juri Lelli 
Cc: Peter Zijlstra 
Cc: Song Liu 
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230406210611.1622492-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf lock contention: Use -M for --map-nr-entries

2023-04-07T00:52:23+00:00

Users often want to change the map size, let's add a short option (-M)
for that.

Signed-off-by: Namhyung Kim 
Acked-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Hao Luo 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Juri Lelli 
Cc: Peter Zijlstra 
Cc: Song Liu 
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230406210611.1622492-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf top: Add --branch-history option

2023-04-04T12:39:56+00:00

Add --branch-history option, to act the same as that option does for
perf report.

Example:

  $ cat tcallf.c
  volatile a = 10000, b = 100000, c;

  __attribute__((noinline)) f2()
  {
          c = a / b;
  }

  __attribute__((noinline)) f1()
  {
          f2();
          f2();
  }
  main()
  {
          while (1)
                  f1();
  }
  $ gcc -w -g -o tcallf tcallf.c
  $ ./tcallf &
  [1] 29409
  $ perf top -e cycles:u  -t $(pidof tcallf) --stdio --no-children --branch-history
     PerfTop:    3819 irqs/sec  kernel: 0.0%  exact:  0.0% lost: 0/0 drop: 0/0 [4000Hz cycles:u],  (target_tid: 29409)
  --------------------------------------------------------------------------------------------------------------------

      49.01%  tcallf.c:5   [.] f2    tcallf
              |
              |--24.91%--f2 tcallf.c:4
              |          |
              |          |--17.14%--f1 tcallf.c:11 (cycles:1)
              |          |          f1 tcallf.c:11
              |          |          f2 tcallf.c:6 (cycles:3)
              |          |          f2 tcallf.c:4
              |          |          f1 tcallf.c:10 (cycles:2)
              |          |          f1 tcallf.c:9
              |          |          main tcallf.c:16 (cycles:1)
              |          |          main tcallf.c:16
              |          |          main tcallf.c:16 (cycles:1)
              |          |          main tcallf.c:16
              |          |          f1 tcallf.c:12 (cycles:1)
              |          |          f1 tcallf.c:12
              |          |          f2 tcallf.c:6 (cycles:3)
              |          |          f2 tcallf.c:4
              |          |          f1 tcallf.c:11 (cycles:1 iter:1 avg_cycles:12)
              |          |          f1 tcallf.c:11
              |          |          f2 tcallf.c:6 (cycles:3 iter:1 avg_cycles:12)
              |          |          f2 tcallf.c:4
              |          |          f1 tcallf.c:10 (cycles:2 iter:1 avg_cycles:12)
              |          |
              |           --7.78%--f1 tcallf.c:10 (cycles:2)
              |                     f1 tcallf.c:9
              |                     main tcallf.c:16 (cycles:1)
              |                     main tcallf.c:16
              |                     main tcallf.c:16 (cycles:1)
              |                     main tcallf.c:16
              |                     f1 tcallf.c:12 (cycles:1)
              |                     f1 tcallf.c:12
              |                     f2 tcallf.c:6 (cycles:3)
              |                     f2 tcallf.c:4
              |                     f1 tcallf.c:11 (cycles:1)
              |                     f1 tcallf.c:11
              |                     f2 tcallf.c:6 (cycles:3)
              |                     f2 tcallf.c:4
              |                     f1 tcallf.c:10 (cycles:2 iter:1 avg_cycles:12)
              |                     f1 tcallf.c:9
              |                     main tcallf.c:16 (cycles:1 iter:1 avg_cycles:12)
              |                     main tcallf.c:16
              |                     main tcallf.c:16 (cycles:1 iter:1 avg_cycles:12)
  ...

  $ pkill tcallf
  [1]+  Terminated              ./tcallf

Signed-off-by: Adrian Hunter 
Cc: Andi Kleen 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: https://lore.kernel.org/r/20230330131833.12864-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf symbol: Add command line support for addr2line path

2023-04-04T12:39:56+00:00

Allow addr2line to be set either on the command line or via the
perfconfig file. This doesn't currently work with llvm-addr2line as
the addr2line code emits two things:
1) the address to decode,
2) a bogus ',' value.
The expectation is the bogus value will generate:
??
??:0
that terminates the addr2line reading. However, the output from
llvm-addr2line is a single line with just the input ',' locking up the
addr2line reading that is expecting a second line.

Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Andres Freund 
Cc: German Gomez 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Nathan Chancellor 
Cc: Nick Desaulniers 
Cc: Peter Zijlstra 
Cc: Sandipan Das 
Cc: Tom Rix 
Cc: llvm@lists.linux.dev
Link: https://lore.kernel.org/r/20230328235543.1082207-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf annotate: Allow objdump to be set in perfconfig

2023-04-04T12:39:56+00:00

Allow the setting of the objdump command in the perfconfig. Update man
page for this new option.

Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Andres Freund 
Cc: German Gomez 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Nathan Chancellor 
Cc: Nick Desaulniers 
Cc: Peter Zijlstra 
Cc: Sandipan Das 
Cc: Tom Rix 
Cc: llvm@lists.linux.dev
Link: https://lore.kernel.org/r/20230328235543.1082207-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf report: Add 'simd' sort field

2023-03-20T22:28:21+00:00

Add 'simd' sort field to visualize SIMD ops in 'perf report'.

Rows are labeled with the SIMD ISA, and the type of predicate (if any):

  - [p] partial predicate
  - [e] empty predicate (no elements in the vector being used)

Example with Arm SPE and SVE (Scalable Vector Extension):

  #include 

  double src[1025], dst[1025];

  int main(void) {
    svfloat64_t vc = svdup_f64(1);
    for(;;)
      for(int i = 0; i < 1025; i += svcntd())
      {
        svbool_t pg = svwhilelt_b64(i, 1025);
        svfloat64_t vsrc = svld1(pg, &src[i]);
        svfloat64_t vdst = svadd_x(pg, vsrc, vc);
        svst1(pg, &dst[i], vdst);
      }
    return 0;
  }

  ... compiled using "gcc-11 -march=armv8-a+sve -O3"

Profiling on a platform that implements FEAT_SVE and FEAT_SPEv1p1:

  $ perf record -e arm_spe_0// -- ./a.out
  $ perf report --itrace=i1i -s overhead,pid,simd,sym

  Overhead      Pid:Command   Simd     Symbol
  ........  ................  .......  ......................

    53.76%    10758:program            [.] main
    46.14%    10758:program   [.] SVE  [.] main
     0.09%    10758:program   [p] SVE  [.] main

The report shows 0.09% of the sampled SVE operations use partial
predicates due to src and dst arrays not being multiples of the vector
register lengths.

Signed-off-by: German Gomez 
Acked-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Anshuman.Khandual@arm.com
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: John Garry 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Mike Leach 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Will Deacon 
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230320151509.1137462-2-james.clark@arm.com
Signed-off-by: James Clark 
Signed-off-by: Arnaldo Carvalho de Melo

perf kvm: Update documentation to reflect new changes

2023-03-15T19:53:43+00:00

Update documentation for new sorting and option '--stdio'.

Reviewed-by: James Clark 
Signed-off-by: Leo Yan 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: John Garry 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230315145112.186603-2-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo

perf record: Update documentation for BPF filters

2023-03-15T14:08:36+00:00

Add more description and examples.

Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: Hao Luo 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Song Liu 
Cc: Stephane Eranian 
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230314234237.3008956-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf record: Add BPF event filter support

2023-03-15T14:08:34+00:00

Use --filter option to set BPF filter for generic events other than the
tracepoints or Intel PT.  The BPF program will check the sample data and
filter according to the expression.

For example, the below is the typical perf record for frequency mode.
The sample period started from 1 and increased gradually.

  $ sudo ./perf record -e cycles true
  $ sudo ./perf script
       perf-exec 2272336 546683.916875:          1 cycles:  ffffffff828499b8 perf_event_exec+0x298 ([kernel.kallsyms])
       perf-exec 2272336 546683.916892:          1 cycles:  ffffffff828499b8 perf_event_exec+0x298 ([kernel.kallsyms])
       perf-exec 2272336 546683.916899:          3 cycles:  ffffffff828499b8 perf_event_exec+0x298 ([kernel.kallsyms])
       perf-exec 2272336 546683.916905:         17 cycles:  ffffffff828499b8 perf_event_exec+0x298 ([kernel.kallsyms])
       perf-exec 2272336 546683.916911:        100 cycles:  ffffffff828499b8 perf_event_exec+0x298 ([kernel.kallsyms])
       perf-exec 2272336 546683.916917:        589 cycles:  ffffffff828499b8 perf_event_exec+0x298 ([kernel.kallsyms])
       perf-exec 2272336 546683.916924:       3470 cycles:  ffffffff828499b8 perf_event_exec+0x298 ([kernel.kallsyms])
       perf-exec 2272336 546683.916930:      20465 cycles:  ffffffff828499b8 perf_event_exec+0x298 ([kernel.kallsyms])
            true 2272336 546683.916940:     119873 cycles:  ffffffff8283afdd perf_iterate_ctx+0x2d ([kernel.kallsyms])
            true 2272336 546683.917003:     461349 cycles:  ffffffff82892517 vma_interval_tree_insert+0x37 ([kernel.kallsyms])
            true 2272336 546683.917237:     635778 cycles:  ffffffff82a11400 security_mmap_file+0x20 ([kernel.kallsyms])

When you add a BPF filter to get samples having periods greater than 1000,
the output would look like below:

  $ sudo ./perf record -e cycles --filter 'period > 1000' true
  $ sudo ./perf script
       perf-exec 2273949 546850.708501:       5029 cycles:  ffffffff826f9e25 finish_wait+0x5 ([kernel.kallsyms])
       perf-exec 2273949 546850.708508:      32409 cycles:  ffffffff826f9e25 finish_wait+0x5 ([kernel.kallsyms])
       perf-exec 2273949 546850.708526:     143369 cycles:  ffffffff82b4cdbf xas_start+0x5f ([kernel.kallsyms])
       perf-exec 2273949 546850.708600:     372650 cycles:  ffffffff8286b8f7 __pagevec_lru_add+0x117 ([kernel.kallsyms])
       perf-exec 2273949 546850.708791:     482953 cycles:  ffffffff829190de __mod_memcg_lruvec_state+0x4e ([kernel.kallsyms])
            true 2273949 546850.709036:     501985 cycles:  ffffffff828add7c tlb_gather_mmu+0x4c ([kernel.kallsyms])
            true 2273949 546850.709292:     503065 cycles:      7f2446d97c03 _dl_map_object_deps+0x973 (/usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2)

Committer notes:

Add stubs for perf_bpf_filter__prepare() and perf_bpf_filter__destroy()
to tools/perf/util/python.c to keep it building.

Signed-off-by: Namhyung Kim 
Acked-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: Hao Luo 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Song Liu 
Cc: Stephane Eranian 
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230314234237.3008956-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf doc: Refresh topdown documentation

2023-02-19T11:10:15+00:00

perf stat now supports --topdown for any platform with the TopdownL1
metric group including Intel before Icelake. Tweak the documentation
to reflect this.

Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexandre Torgue 
Cc: Andrii Nakryiko 
Cc: Athira Rajeev 
Cc: Caleb Biggers 
Cc: Eduard Zingerman 
Cc: Florian Fischer 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jing Zhang 
Cc: Jiri Olsa 
Cc: John Garry 
Cc: Kajol Jain 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Maxime Coquelin 
Cc: Namhyung Kim 
Cc: Perry Taylor 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Sandipan Das 
Cc: Sean Christopherson 
Cc: Stephane Eranian 
Cc: Suzuki Poulouse 
Cc: Xing Zhengjun 
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-stm32@st-md-mailman.stormreply.com
Link: https://lore.kernel.org/r/20230219092848.639226-43-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo