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  1. 11 10月, 2019 2 次提交
    • J
      perf diff: Report noisy for cycles diff · cebf7d51
      由 Jin Yao 提交于 
      This patch prints the stddev and hist for the cycles diff of program
block. It can help us to understand if the cycles is noisy or not.

This patch is inspired by Andi Kleen's patch:

  https://lwn.net/Articles/600471/

We create new option '--cycles-hist'.

Example:

  perf record -b ./div
  perf record -b ./div
  perf diff -c cycles

  # Baseline                                [Program Block Range] Cycles Diff  Shared Object      Symbol
  # ........  .......................................................... ....  .................  ............................
  #
      46.72%                                      [div.c:40 -> div.c:40]    0  div                [.] main
      46.72%                                      [div.c:42 -> div.c:44]    0  div                [.] main
      46.72%                                      [div.c:42 -> div.c:39]    0  div                [.] main
      20.54%                          [random_r.c:357 -> random_r.c:394]    1  libc-2.27.so       [.] __random_r
      20.54%                          [random_r.c:357 -> random_r.c:380]    0  libc-2.27.so       [.] __random_r
      20.54%                          [random_r.c:388 -> random_r.c:388]    0  libc-2.27.so       [.] __random_r
      20.54%                          [random_r.c:388 -> random_r.c:391]    0  libc-2.27.so       [.] __random_r
      17.04%                              [random.c:288 -> random.c:291]    0  libc-2.27.so       [.] __random
      17.04%                              [random.c:291 -> random.c:291]    0  libc-2.27.so       [.] __random
      17.04%                              [random.c:293 -> random.c:293]    0  libc-2.27.so       [.] __random
      17.04%                              [random.c:295 -> random.c:295]    0  libc-2.27.so       [.] __random
      17.04%                              [random.c:295 -> random.c:295]    0  libc-2.27.so       [.] __random
      17.04%                              [random.c:298 -> random.c:298]    0  libc-2.27.so       [.] __random
       8.40%                                      [div.c:22 -> div.c:25]    0  div                [.] compute_flag
       8.40%                                      [div.c:27 -> div.c:28]    0  div                [.] compute_flag
       5.14%                                    [rand.c:26 -> rand.c:27]    0  libc-2.27.so       [.] rand
       5.14%                                    [rand.c:28 -> rand.c:28]    0  libc-2.27.so       [.] rand
       2.15%                                  [rand@plt+0 -> rand@plt+0]    0  div                [.] rand@plt
       0.00%                                                                   [kernel.kallsyms]  [k] __x86_indirect_thunk_rax
       0.00%                                [do_mmap+714 -> do_mmap+732]  -10  [kernel.kallsyms]  [k] do_mmap
       0.00%                                [do_mmap+737 -> do_mmap+765]    1  [kernel.kallsyms]  [k] do_mmap
       0.00%                                [do_mmap+262 -> do_mmap+299]    0  [kernel.kallsyms]  [k] do_mmap
       0.00%  [__x86_indirect_thunk_r15+0 -> __x86_indirect_thunk_r15+0]    7  [kernel.kallsyms]  [k] __x86_indirect_thunk_r15
       0.00%            [native_sched_clock+0 -> native_sched_clock+119]   -1  [kernel.kallsyms]  [k] native_sched_clock
       0.00%                 [native_write_msr+0 -> native_write_msr+16]  -13  [kernel.kallsyms]  [k] native_write_msr

When we enable the option '--cycles-hist', the output is

  perf diff -c cycles --cycles-hist

  # Baseline                                [Program Block Range] Cycles Diff        stddev/Hist  Shared Object      Symbol
  # ........  .......................................................... ....  .................  .................  ............................
  #
      46.72%                                      [div.c:40 -> div.c:40]    0  ± 37.8% ▁█▁▁██▁█   div                [.] main
      46.72%                                      [div.c:42 -> div.c:44]    0  ± 49.4% ▁▁▂█▂▂▂▂   div                [.] main
      46.72%                                      [div.c:42 -> div.c:39]    0  ± 24.1% ▃█▂▄▁▃▂▁   div                [.] main
      20.54%                          [random_r.c:357 -> random_r.c:394]    1  ± 33.5% ▅▂▁█▃▁▂▁   libc-2.27.so       [.] __random_r
      20.54%                          [random_r.c:357 -> random_r.c:380]    0  ± 39.4% ▁▁█▁██▅▁   libc-2.27.so       [.] __random_r
      20.54%                          [random_r.c:388 -> random_r.c:388]    0                     libc-2.27.so       [.] __random_r
      20.54%                          [random_r.c:388 -> random_r.c:391]    0  ± 41.2% ▁▃▁▂█▄▃▁   libc-2.27.so       [.] __random_r
      17.04%                              [random.c:288 -> random.c:291]    0  ± 48.8% ▁▁▁▁███▁   libc-2.27.so       [.] __random
      17.04%                              [random.c:291 -> random.c:291]    0  ±100.0% ▁█▁▁▁▁▁▁   libc-2.27.so       [.] __random
      17.04%                              [random.c:293 -> random.c:293]    0  ±100.0% ▁█▁▁▁▁▁▁   libc-2.27.so       [.] __random
      17.04%                              [random.c:295 -> random.c:295]    0  ±100.0% ▁█▁▁▁▁▁▁   libc-2.27.so       [.] __random
      17.04%                              [random.c:295 -> random.c:295]    0                     libc-2.27.so       [.] __random
      17.04%                              [random.c:298 -> random.c:298]    0  ± 75.6% ▃█▁▁▁▁▁▁   libc-2.27.so       [.] __random
       8.40%                                      [div.c:22 -> div.c:25]    0  ± 42.1% ▁▃▁▁███▁   div                [.] compute_flag
       8.40%                                      [div.c:27 -> div.c:28]    0  ± 41.8% ██▁▁▄▁▁▄   div                [.] compute_flag
       5.14%                                    [rand.c:26 -> rand.c:27]    0  ± 37.8% ▁▁▁████▁   libc-2.27.so       [.] rand
       5.14%                                    [rand.c:28 -> rand.c:28]    0                     libc-2.27.so       [.] rand
       2.15%                                  [rand@plt+0 -> rand@plt+0]    0                     div                [.] rand@plt
       0.00%                                                                                      [kernel.kallsyms]  [k] __x86_indirect_thunk_rax
       0.00%                                [do_mmap+714 -> do_mmap+732]  -10                     [kernel.kallsyms]  [k] do_mmap
       0.00%                                [do_mmap+737 -> do_mmap+765]    1                     [kernel.kallsyms]  [k] do_mmap
       0.00%                                [do_mmap+262 -> do_mmap+299]    0                     [kernel.kallsyms]  [k] do_mmap
       0.00%  [__x86_indirect_thunk_r15+0 -> __x86_indirect_thunk_r15+0]    7                     [kernel.kallsyms]  [k] __x86_indirect_thunk_r15
       0.00%            [native_sched_clock+0 -> native_sched_clock+119]   -1  ± 38.5% ▄█▁        [kernel.kallsyms]  [k] native_sched_clock
       0.00%                 [native_write_msr+0 -> native_write_msr+16]  -13  ± 47.1% ▁█▇▃▁▁     [kernel.kallsyms]  [k] native_write_msr

 v8:
 ---
 Rebase to perf/core branch

 v7:
 ---
 1. v6 got Jiri's ACK.
 2. Rebase to latest perf/core branch.

 v6:
 ---
 1. Jiri provides better code for using data__hpp_register() in ui_init().
    Use this code in v6.

 v5:
 ---
 1. Refine the use of data__hpp_register() in ui_init() according to
    Jiri's suggestion.

 v4:
 ---
 1. Rename the new option from '--noisy' to '--cycles-hist'
 2. Remove the option '-n'.
 3. Only update the spark value and stats when '--cycles-hist' is enabled.
 4. Remove the code of printing '..'.

 v3:
 ---
 1. Move the histogram to a separate column
 2. Move the svals[] out of struct stats

 v2:
 ---
 Jiri got a compile error,

  CC       builtin-diff.o
  builtin-diff.c: In function ‘compute_cycles_diff’:
  builtin-diff.c:712:10: error: taking the absolute value of unsigned type ‘u64’ {aka ‘long unsigned int’} has no effect [-Werror=absolute-value]
  712 |          labs(pair->block_info->cycles_spark[i] -
      |          ^~~~

 Because the result of u64 - u64 is still u64. Now we change the type of
 cycles_spark[] to s64.
Signed-off-by: NJin Yao <yao.jin@linux.intel.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20190925011446.30678-1-yao.jin@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      cebf7d51
    • J
      perf tools: Propagate CFLAGS to libperf · 55542113
      由 Jiri Olsa 提交于 
      Andi reported that 'make DEBUG=1' does not propagate to the libbperf
code. It's true also for the other flags. Changing the code to propagate
the global build flags to libperf compilation.
Reported-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20191011122155.15738-1-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      55542113
  3. 10 10月, 2019 32 次提交
  5. 09 10月, 2019 6 次提交
    • A
      perf trace: Introduce --filter for tracepoint events · d4097f19
      由 Arnaldo Carvalho de Melo 提交于 
      Similar to what is in 'perf record', works just like there:

  # perf trace -e msr:*
   328.297 :0/0 msr:write_msr(msr: FS_BASE, val: 140240388381888)
   328.302 :0/0 msr:write_msr(msr: FS_BASE, val: 140240388381888)
   328.306 :0/0 msr:write_msr(msr: FS_BASE, val: 140240388381888)
   328.317 :0/0 msr:write_msr(msr: FS_BASE, val: 140240388381888)
   328.322 :0/0 msr:write_msr(msr: FS_BASE, val: 140240388381888)
   328.327 :0/0 msr:write_msr(msr: FS_BASE, val: 140240388381888)
   328.331 :0/0 msr:write_msr(msr: FS_BASE, val: 140240388381888)
   328.336 :0/0 msr:write_msr(msr: FS_BASE, val: 140240388381888)
   328.340 :0/0 ^Cmsr:write_msr(msr: FS_BASE, val: 140240388381888)
  #

So, for a system wide trace session looking at the write_msr tracepoint
we see a flood of MSR_FS_BASE, we need to get the number for that:

  # grep FS_BASE /tmp/build/perf/trace/beauty/generated/x86_arch_MSRs_array.c
	[0xc0000100 - x86_64_specific_MSRs_offset] = "FS_BASE",
  #

And then use it in a filter:

  # perf trace -e msr:* --filter="msr!=0xc0000100"
  <SNIP>
   942.177 :0/0 msr:write_msr(msr: IA32_TSC_DEADLINE, val: 3056931068232)
   942.199 :0/0 msr:write_msr(msr: IA32_TSC_DEADLINE, val: 3057135655252)
   942.203 :0/0 msr:write_msr(msr: IA32_TSC_DEADLINE, val: 3056931068222)
   942.231 :0/0 msr:write_msr(msr: IA32_TSC_DEADLINE, val: 3056998373022)
   942.241 :0/0 msr:write_msr(msr: IA32_TSC_DEADLINE, val: 3056931068236)
  <SNIP>
  #

Ok, lets filter that too, too noisy:

  # grep TSC_DEADLINE /tmp/build/perf/trace/beauty/generated/x86_arch_MSRs_array.c
	[0x000006E0] = "IA32_TSC_DEADLINE",
  #

  # perf trace -e msr:* --filter="msr!=0xc0000100 && msr!=0x6e0" -a sleep 0.1
     0.000 :0/0 msr:read_msr(msr: IA32_TSC_ADJUST)
     0.066 CPU 0/KVM/4895 msr:write_msr(msr: IA32_SPEC_CTRL, val: 6)
     0.070 CPU 0/KVM/4895 msr:write_msr(msr: 0x830, val: 34359740667)
     0.099 CPU 0/KVM/4895 msr:read_msr(msr: IA32_SYSENTER_ESP, val: -2199021993472)
     0.100 CPU 0/KVM/4895 msr:read_msr(msr: IA32_APICBASE, val: 4276096000)
     0.101 CPU 0/KVM/4895 msr:read_msr(msr: IA32_DEBUGCTLMSR)
     0.109 :0/0 msr:write_msr(msr: IA32_SPEC_CTRL)
     1.000 :0/0 msr:write_msr(msr: 0x830, val: 17179871485)
    18.893 :0/0 msr:write_msr(msr: 0x83f, val: 246)
    28.810 :0/0 msr:write_msr(msr: 0x830, val: 68719479037)
    40.117 CPU 0/KVM/4895 msr:write_msr(msr: IA32_SPEC_CTRL, val: 6)
    40.127 CPU 0/KVM/4895 msr:read_msr(msr: IA32_DEBUGCTLMSR)
    40.139 CPU 0/KVM/4895 msr:write_msr(msr: LSTAR, val: -2130661312)
    40.141 CPU 0/KVM/4895 msr:write_msr(msr: SYSCALL_MASK, val: 14080)
    40.142 CPU 0/KVM/4895 msr:write_msr(msr: TSC_AUX)
    40.144 CPU 0/KVM/4895 msr:write_msr(msr: KERNEL_GS_BASE)
    40.147 CPU 0/KVM/4895 msr:write_msr(msr: IA32_SPEC_CTRL)
    40.148 CPU 0/KVM/4895 msr:write_msr(msr: IA32_FLUSH_CMD, val: 1)
    40.151 CPU 0/KVM/4895 msr:write_msr(msr: IA32_SPEC_CTRL, val: 6)
  ^C
  #

One can combine that with filtering pids as well:

  # perf trace -e msr:* --filter="msr!=0xc0000100 && msr!=0x6e0" --filter-pids 4895 -a sleep 0.09
     0.000 :0/0 msr:write_msr(msr: 0x830, val: 4294969597)
     0.291 gnome-terminal/2790 msr:write_msr(msr: SYSCALL_MASK, val: 292608)
     0.294 gnome-terminal/2790 msr:write_msr(msr: LSTAR, val: -1935671280)
     0.295 gnome-terminal/2790 msr:write_msr(msr: TSC_AUX, val: 6)
    10.940 gnome-terminal/2790 msr:write_msr(msr: 0x830, val: 4294969597)
    15.943 gnome-shell/2096 msr:write_msr(msr: 0x830, val: 4294969597)
    16.975 :0/0 msr:write_msr(msr: 0x830, val: 4294969597)
    19.560 :0/0 msr:write_msr(msr: 0x83f, val: 246)
    25.162 :0/0 msr:read_msr(msr: IA32_TSC_ADJUST)
    25.807 JS Watchdog/3635 msr:write_msr(msr: IA32_SPEC_CTRL, val: 6)
    25.820 :0/0 msr:write_msr(msr: IA32_SPEC_CTRL)
    25.941 gnome-terminal/2790 msr:write_msr(msr: 0x830, val: 4294969597)
    26.941 gnome-terminal/2790 msr:write_msr(msr: 0x830, val: 4294969597)
    29.942 gnome-terminal/2790 msr:write_msr(msr: 0x830, val: 4294969597)
    45.313 :0/0 msr:write_msr(msr: 0x83f, val: 246)
    56.945 gnome-terminal/2790 msr:write_msr(msr: 0x830, val: 4294969597)
    60.946 gnome-terminal/2790 msr:write_msr(msr: 0x830, val: 4294969597)
    74.096 JS Watchdog/8971 msr:write_msr(msr: IA32_SPEC_CTRL, val: 6)
    74.130 :0/0 msr:write_msr(msr: IA32_SPEC_CTRL)
    79.673 :0/0 msr:write_msr(msr: 0x83f, val: 246)
    79.947 gnome-terminal/2790 msr:write_msr(msr: 0x830, val: 17179871485)
  #

Or for just a pid, with callchains:

  # grep SYSCALL_MAS /tmp/build/perf/trace/beauty/generated/x86_arch_MSRs_array.c
	[0xc0000084 - x86_64_specific_MSRs_offset] = "SYSCALL_MASK",
  # perf trace -e msr:* --filter="msr==0xc0000084" --pid 2790 --call-graph=dwarf

     0.000 gnome-terminal/2790 msr:write_msr(msr: SYSCALL_MASK, val: 292608)
                                       do_trace_write_msr ([kernel.kallsyms])
                                       do_trace_write_msr ([kernel.kallsyms])
                                       kvm_on_user_return ([kvm])
                                       fire_user_return_notifiers ([kernel.kallsyms])
                                       exit_to_usermode_loop ([kernel.kallsyms])
                                       do_syscall_64 ([kernel.kallsyms])
                                       entry_SYSCALL_64 ([kernel.kallsyms])
                                       __GI___poll (inlined)
  9299.073 gnome-terminal/2790 msr:write_msr(msr: SYSCALL_MASK, val: 292608)
                                       do_trace_write_msr ([kernel.kallsyms])
                                       do_trace_write_msr ([kernel.kallsyms])
                                       kvm_on_user_return ([kvm])
                                       fire_user_return_notifiers ([kernel.kallsyms])
                                       exit_to_usermode_loop ([kernel.kallsyms])
                                       do_syscall_64 ([kernel.kallsyms])
                                       entry_SYSCALL_64 ([kernel.kallsyms])
                                       __GI___poll (inlined)
  9348.374 gnome-terminal/2790 msr:write_msr(msr: SYSCALL_MASK, val: 292608)
                                       do_trace_write_msr ([kernel.kallsyms])
                                       do_trace_write_msr ([kernel.kallsyms])
                                       kvm_on_user_return ([kvm])
                                       fire_user_return_notifiers ([kernel.kallsyms])
                                       exit_to_usermode_loop ([kernel.kallsyms])
                                       do_syscall_64 ([kernel.kallsyms])
                                       entry_SYSCALL_64 ([kernel.kallsyms])
                                       __GI___poll (inlined)
  <SNIP>
  #

Ok, just another form of KVM to emit MSRs :-)

Next step: elliminate those greps by getting the filter expression,
looking for arg names, then for the arrays associated with it to do a
reverse lookup.

Also allow those filters to be associated with strace-like syscall
names.

After that: augment the 'val' arg for 'msr:write_msr' based on the first
arg, 'msr'.

Then, do that with eBPF too, not just with tracepoint filters.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-95bfe5d4tzy5f66bx49d05rj@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      d4097f19
    • A
      perf evlist: Introduce append_tp_filter_pid() and append_tp_filter_pids() · 1827ab5b
      由 Arnaldo Carvalho de Melo 提交于 
      We'll need this to support 'perf trace e tracepoint --filter=expr', as
the command line tracepoint filter is attache to the preceding evsel,
just like in 'perf record' and when we go to set pid filters, which we
do at the minimum to filter 'perf trace' own syscalls, we need to
append, not set the tp filter.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-daynpknni44ywuzi8iua57nn@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      1827ab5b
    • A
      perf evlist: Introduce append_tp_filter() method · 53c92f73
      由 Arnaldo Carvalho de Melo 提交于 
      Will be used by 'perf trace' to support 'perf trace --filter', we need
to append to any pre-existing filter.

When parse_filter() gets invoked to process --filter, it'll set the
filter to that specified on the command line, later on, when we filter
out 'perf trace' own pid to avoid an event feedback loop, we need to
preserve the command line filter put in place by parse_filter().

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-h9rot08qmxlnfmte0holt68x@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      53c92f73
    • A
      perf evlist: Factor out asprintf routine to build a tracepoint pid filter · 05cea449
      由 Arnaldo Carvalho de Melo 提交于 
      Will be used to append such lists to existing filters.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-798vlyqfqw938ehoe8etivx1@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      05cea449
    • A
      perf trace: Associate the "msr" tracepoint arg name with x86_MSR__scnprintf() · c330ef28
      由 Arnaldo Carvalho de Melo 提交于 
      So that we can go from:

  # perf trace -e msr:write_msr --max-stack=16 sleep 1
       0.000 sleep/6740 msr:write_msr(msr: 3221225728, val: 139636317451648)
                                         do_trace_write_msr ([kernel.kallsyms])
                                         do_trace_write_msr ([kernel.kallsyms])
                                         do_arch_prctl_64 ([kernel.kallsyms])
                                         __x64_sys_arch_prctl ([kernel.kallsyms])
                                         do_syscall_64 ([kernel.kallsyms])
                                         entry_SYSCALL_64 ([kernel.kallsyms])
                                         init_tls (/usr/lib64/ld-2.29.so)
                                         dl_main (/usr/lib64/ld-2.29.so)
                                         _dl_sysdep_start (/usr/lib64/ld-2.29.so)
                                         _dl_start (/usr/lib64/ld-2.29.so)
  #

To:

  # perf trace -e msr:write_msr --max-stack=16 sleep 1
     0.000 sleep/8519 msr:write_msr(msr: FS_BASE, val: 139878031705472)
                                       do_trace_write_msr ([kernel.kallsyms])
                                       do_trace_write_msr ([kernel.kallsyms])
                                       do_arch_prctl_64 ([kernel.kallsyms])
                                       __x64_sys_arch_prctl ([kernel.kallsyms])
                                       do_syscall_64 ([kernel.kallsyms])
                                       entry_SYSCALL_64 ([kernel.kallsyms])
                                       init_tls (/usr/lib64/ld-2.29.so)
                                       dl_main (/usr/lib64/ld-2.29.so)
                                       _dl_sysdep_start (/usr/lib64/ld-2.29.so)
                                       _dl_start (/usr/lib64/ld-2.29.so)
  #

This, in reverse, will allow for symbolic system call/tracepoint
filtering.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-q1q4unmqja5ex7dy0kb5cjaa@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      c330ef28
    • A
      perf trace beauty: Add the glue for the autogenerated MSR arrays · 646b3e2c
      由 Arnaldo Carvalho de Melo 提交于 
      We need to wrap those autogenerated string arrays with the
strarrays__scnprintf() formatter, do it.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-wqjz4kwi4a0ot6lsis3kc65j@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      646b3e2c