Enable tprof

lib/benchee/profile.ex

@@ -25,6 +25,13 @@ defmodule Benchee.Profile do
 
   @default_profiler :eprof
   @builtin_profilers [:cprof, :eprof, :fprof]
+  # https://hexdocs.pm/mix/1.17.0/Mix.Tasks.Profile.Tprof.html
+  # Was introduced in 1.17.0, it also requires OTP 27 but I trust it to error fine for
+  # that case itself
+  if Version.match?(System.version(), ">= 1.17.0") do
+    @builtin_profilers [:tprof | @builtin_profilers]
+  end
+
   # we run the function a bunch already, no need for further warmup
   @default_profiler_opts [warmup: false]
 

samples/fast_with_profiling.exs

@@ -0,0 +1,157 @@
+list = Enum.to_list(1..10_000)
+map_fun = fn i -> [i, i * i] end
+
+Benchee.run(
+  %{
+    "flat_map" => fn -> Enum.flat_map(list, map_fun) end,
+    "map.flatten" => fn -> list |> Enum.map(map_fun) |> List.flatten() end
+  },
+  warmup: 0.1,
+  time: 0.3,
+  memory_time: 0.3,
+  profile_after: true
+)
+
+Benchee.run(
+  %{
+    "flat_map" => fn -> Enum.flat_map(list, map_fun) end,
+    "map.flatten" => fn -> list |> Enum.map(map_fun) |> List.flatten() end
+  },
+  warmup: 0.1,
+  time: 0.3,
+  memory_time: 0.3,
+  profile_after: :tprof
+)
+
+# tobi@qiqi:~/github/benchee(main)$ mix run samples/fast_with_profiling.exs
+# Compiling 2 files (.ex)
+# Operating System: Linux
+# CPU Information: AMD Ryzen 9 5900X 12-Core Processor
+# Number of Available Cores: 24
+# Available memory: 31.26 GB
+# Elixir 1.17.3
+# Erlang 27.1
+# JIT enabled: true
+
+# Benchmark suite executing with the following configuration:
+# warmup: 100 ms
+# time: 300 ms
+# memory time: 300 ms
+# reduction time: 0 ns
+# parallel: 1
+# inputs: none specified
+# Estimated total run time: 1 s 400 ms
+
+# Benchmarking flat_map ...
+# Benchmarking map.flatten ...
+# Calculating statistics...
+# Formatting results...
+
+# Name                  ips        average  deviation         median         99th %
+# flat_map           2.24 K      447.25 μs    ±53.59%      322.59 μs     1096.32 μs
+# map.flatten        1.61 K      620.76 μs    ±38.00%      689.02 μs      963.44 μs
+
+# Comparison:
+# flat_map           2.24 K
+# map.flatten        1.61 K - 1.39x slower +173.51 μs
+
+# Memory usage statistics:
+
+# Name           Memory usage
+# flat_map             625 KB
+# map.flatten       781.25 KB - 1.25x memory usage +156.25 KB
+
+# **All measurements for memory usage were the same**
+
+# Profiling flat_map with eprof...
+
+# Profile results of #PID<0.1617.0>
+# #                                               CALLS     % TIME µS/CALL
+# Total                                           30004 100.0 3779    0.13
+# Enum.flat_map/2                                     1  0.00    0    0.00
+# anonymous fn/2 in :elixir_compiler_2.__FILE__/1     1  0.00    0    0.00
+# :erlang.apply/2                                     1  0.03    1    1.00
+# :erlang.++/2                                    10000 14.58  551    0.06
+# Enum.flat_map_list/2                            10001 42.13 1592    0.16
+# anonymous fn/1 in :elixir_compiler_2.__FILE__/1 10000 43.27 1635    0.16
+
+# Profile done over 6 matching functions
+
+# Profiling map.flatten with eprof...
+
+# Profile results of #PID<0.1619.0>
+# #                                               CALLS     % TIME µS/CALL
+# Total                                           60007 100.0 5281    0.09
+# List.flatten/1                                      1  0.00    0    0.00
+# Enum.map/2                                          1  0.00    0    0.00
+# :lists.flatten/1                                    1  0.00    0    0.00
+# :erlang.apply/2                                     1  0.04    2    2.00
+# anonymous fn/2 in :elixir_compiler_2.__FILE__/1     1  0.04    2    2.00
+# anonymous fn/1 in :elixir_compiler_2.__FILE__/1 10000 19.90 1051    0.11
+# Enum."-map/2-lists^map/1-1-"/2                  10001 26.60 1405    0.14
+# :lists.do_flatten/2                             40001 53.42 2821    0.07
+
+# Profile done over 8 matching functions
+# Operating System: Linux
+# CPU Information: AMD Ryzen 9 5900X 12-Core Processor
+# Number of Available Cores: 24
+# Available memory: 31.26 GB
+# Elixir 1.17.3
+# Erlang 27.1
+# JIT enabled: true
+
+# Benchmark suite executing with the following configuration:
+# warmup: 100 ms
+# time: 300 ms
+# memory time: 300 ms
+# reduction time: 0 ns
+# parallel: 1
+# inputs: none specified
+# Estimated total run time: 1 s 400 ms
+
+# Benchmarking flat_map ...
+# Benchmarking map.flatten ...
+# Calculating statistics...
+# Formatting results...
+
+# Name                  ips        average  deviation         median         99th %
+# flat_map           2.42 K      412.87 μs    ±48.32%      323.59 μs      737.84 μs
+# map.flatten        1.72 K      582.68 μs    ±35.48%      673.13 μs      987.99 μs
+
+# Comparison:
+# flat_map           2.42 K
+# map.flatten        1.72 K - 1.41x slower +169.81 μs
+
+# Memory usage statistics:
+
+# Name           Memory usage
+# flat_map             625 KB
+# map.flatten       781.25 KB - 1.25x memory usage +156.25 KB
+
+# **All measurements for memory usage were the same**
+
+# Profiling flat_map with tprof...
+
+# Profile results of #PID<0.3062.0>
+# #                                               CALLS      % TIME µS/CALL
+# Total                                           30003 100.00 3686    0.12
+# Enum.flat_map/2                                     1   0.00    0    0.00
+# anonymous fn/2 in :elixir_compiler_2.__FILE__/1     1   0.05    2    2.00
+# :erlang.++/2                                    10000  14.46  533    0.05
+# anonymous fn/1 in :elixir_compiler_2.__FILE__/1 10000  33.67 1241    0.12
+# Enum.flat_map_list/2                            10001  51.82 1910    0.19
+
+# Profile done over 5 matching functions
+
+# Profiling map.flatten with tprof...
+
+# Profile results of #PID<0.3064.0>
+# #                                               CALLS      % TIME µS/CALL
+# Total                                           60006 100.00 5316    0.09
+# List.flatten/1                                      1   0.00    0    0.00
+# Enum.map/2                                          1   0.00    0    0.00
+# :lists.flatten/1                                    1   0.00    0    0.00
+# anonymous fn/2 in :elixir_compiler_2.__FILE__/1     1   0.06    3    3.00
+# anonymous fn/1 in :elixir_compiler_2.__FILE__/1 10000  24.72 1314    0.13
+# Enum."-map/2-lists^map/1-1-"/2                  10001  25.81 1372    0.14
+# :lists.do_flatten/2                             40001  49.42 2627    0.07

test/benchee/profile_test.exs

@@ -89,8 +89,7 @@
     assert_receive {:profiling, ^name, ^profiler}
   end
 
-  @profilers Profile.builtin_profilers()
-  for profiler <- @profilers do
+  for profiler <- Profile.builtin_profilers() do
     @profiler profiler
     # can't say warmup as some profilers will have it in the profile messing with the test
     describe "warming up behavior with #{@profiler}" do
@@ -103,7 +102,7 @@
       end
 
       # can't say warmup in the test description as eprof picks it up and then it matches
       test "the function will be called exactly once by default for profiling" do
         retrying(fn ->
           output = capture_profile_io_and_message_with_config(@profiler)