Primiano Tucci | 58a20ff | 2021-11-18 18:38:55 +0000 | [diff] [blame] | 1 | // Copyright (C) 2019 The Android Open Source Project |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | // you may not use this file except in compliance with the License. |
| 5 | // You may obtain a copy of the License at |
| 6 | // |
| 7 | // http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | // |
| 9 | // Unless required by applicable law or agreed to in writing, software |
| 10 | // distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | // See the License for the specific language governing permissions and |
| 13 | // limitations under the License. |
| 14 | |
| 15 | #include <functional> |
| 16 | #include <random> |
| 17 | #include <unordered_map> |
| 18 | |
| 19 | #include <benchmark/benchmark.h> |
| 20 | #include <stdio.h> |
| 21 | #include <sys/mman.h> |
| 22 | #include <unistd.h> |
| 23 | |
| 24 | #include "perfetto/base/logging.h" |
| 25 | #include "perfetto/ext/base/file_utils.h" |
| 26 | #include "perfetto/ext/base/flat_hash_map.h" |
| 27 | #include "perfetto/ext/base/hash.h" |
| 28 | #include "perfetto/ext/base/scoped_file.h" |
| 29 | #include "perfetto/ext/base/string_view.h" |
| 30 | |
| 31 | // This benchmark allows to compare our FlatHashMap implementation against |
| 32 | // reference implementations from Absl (Google), Folly F14 (FB), and Tssil's |
| 33 | // reference RobinHood hashmap. |
| 34 | // Those libraries are not checked in into the repo. If you want to reproduce |
| 35 | // the benchmark you need to: |
| 36 | // - Manually install the three libraries using following the instructions in |
| 37 | // their readme (they all use cmake). |
| 38 | // - When running cmake, remember to pass |
| 39 | // -DCMAKE_BUILD_TYPE=Release -DCMAKE_CXX_FLAGS='-DNDEBUG -O3 -msse4.2 -mavx'. |
| 40 | // That sets cflags for a more fair comparison. |
| 41 | // - Set is_debug=false in the GN args. |
| 42 | // - Set the GN var perfetto_benchmark_3p_libs_prefix="/usr/local" (or whatever |
| 43 | // other directory you set as DESTDIR when running make install). |
| 44 | // The presence of the perfetto_benchmark_3p_libs_prefix GN variable will |
| 45 | // automatically define PERFETTO_HASH_MAP_COMPARE_THIRD_PARTY_LIBS. |
| 46 | |
| 47 | #if defined(PERFETTO_HASH_MAP_COMPARE_THIRD_PARTY_LIBS) |
| 48 | |
| 49 | // Last tested: https://github.com/abseil/abseil-cpp @ f2dbd918d. |
| 50 | #include <absl/container/flat_hash_map.h> |
| 51 | |
| 52 | // Last tested: https://github.com/facebook/folly @ 028a9abae3. |
| 53 | #include <folly/container/F14Map.h> |
| 54 | |
| 55 | // Last tested: https://github.com/Tessil/robin-map @ a603419b9. |
| 56 | #include <tsl/robin_map.h> |
| 57 | #endif |
| 58 | |
| 59 | namespace { |
| 60 | |
| 61 | using namespace perfetto; |
| 62 | using benchmark::Counter; |
| 63 | using perfetto::base::AlreadyHashed; |
| 64 | using perfetto::base::LinearProbe; |
| 65 | using perfetto::base::QuadraticHalfProbe; |
| 66 | using perfetto::base::QuadraticProbe; |
| 67 | |
| 68 | // Our FlatHashMap doesn't have a STL-like interface, mainly because we use |
| 69 | // columnar-oriented storage, not array-of-tuples, so we can't easily map into |
| 70 | // that interface. This wrapper makes our FlatHashMap compatible with STL (just |
| 71 | // for what it takes to build this translation unit), at the cost of some small |
| 72 | // performance penalty (around 1-2%). |
| 73 | template <typename Key, typename Value, typename Hasher, typename Probe> |
| 74 | class Ours : public base::FlatHashMap<Key, Value, Hasher, Probe> { |
| 75 | public: |
| 76 | struct Iterator { |
| 77 | using value_type = std::pair<const Key&, Value&>; |
| 78 | Iterator(const Key& k, Value& v) : pair_{k, v} {} |
| 79 | value_type* operator->() { return &pair_; } |
| 80 | value_type& operator*() { return pair_; } |
| 81 | bool operator==(const Iterator& other) const { |
| 82 | return &pair_.first == &other.pair_.first; |
| 83 | } |
| 84 | bool operator!=(const Iterator& other) const { return !operator==(other); } |
| 85 | value_type pair_; |
| 86 | }; |
| 87 | |
| 88 | void insert(std::pair<Key, Value>&& pair) { |
| 89 | this->Insert(std::move(pair.first), std::move(pair.second)); |
| 90 | } |
| 91 | |
| 92 | Iterator find(const Key& key) { |
| 93 | const size_t idx = this->FindInternal(key); |
| 94 | return Iterator(this->keys_[idx], this->values_[idx]); |
| 95 | } |
| 96 | |
| 97 | Iterator end() { |
| 98 | return Iterator(this->keys_[this->kNotFound], |
| 99 | this->values_[this->kNotFound]); |
| 100 | } |
| 101 | }; |
| 102 | |
| 103 | std::vector<uint64_t> LoadTraceStrings(benchmark::State& state) { |
| 104 | std::vector<uint64_t> str_hashes; |
| 105 | // This requires that the user has downloaded the file |
| 106 | // go/perfetto-benchmark-trace-strings into /tmp/trace_strings. The file is |
| 107 | // too big (2.3 GB after uncompression) and it's not worth adding it to the |
| 108 | // //test/data. Also it contains data from a team member's phone and cannot |
| 109 | // be public. |
| 110 | base::ScopedFstream f(fopen("/tmp/trace_strings", "re")); |
| 111 | if (!f) { |
| 112 | state.SkipWithError( |
| 113 | "Test strings missing. Googlers: download " |
| 114 | "go/perfetto-benchmark-trace-strings and save into /tmp/trace_strings"); |
| 115 | return str_hashes; |
| 116 | } |
| 117 | char line[4096]; |
| 118 | while (fgets(line, sizeof(line), *f)) { |
| 119 | base::Hash hasher; |
| 120 | hasher.Update(line, strlen(line)); |
| 121 | str_hashes.emplace_back(hasher.digest()); |
| 122 | } |
| 123 | return str_hashes; |
| 124 | } |
| 125 | |
| 126 | bool IsBenchmarkFunctionalOnly() { |
| 127 | return getenv("BENCHMARK_FUNCTIONAL_TEST_ONLY") != nullptr; |
| 128 | } |
| 129 | |
| 130 | size_t num_samples() { |
| 131 | return IsBenchmarkFunctionalOnly() ? size_t(100) : size_t(10 * 1000 * 1000); |
| 132 | } |
| 133 | |
| 134 | // Uses directly the base::FlatHashMap with no STL wrapper. Configures the map |
| 135 | // in append-only mode. |
| 136 | void BM_HashMap_InsertTraceStrings_AppendOnly(benchmark::State& state) { |
| 137 | std::vector<uint64_t> hashes = LoadTraceStrings(state); |
| 138 | for (auto _ : state) { |
| 139 | base::FlatHashMap<uint64_t, uint64_t, AlreadyHashed<uint64_t>, LinearProbe, |
| 140 | /*AppendOnly=*/true> |
| 141 | mapz; |
| 142 | for (uint64_t hash : hashes) |
| 143 | mapz.Insert(hash, 42); |
| 144 | |
| 145 | benchmark::ClobberMemory(); |
| 146 | state.counters["uniq"] = Counter(static_cast<double>(mapz.size())); |
| 147 | } |
| 148 | state.counters["tot"] = Counter(static_cast<double>(hashes.size()), |
| 149 | Counter::kIsIterationInvariant); |
| 150 | state.counters["rate"] = Counter(static_cast<double>(hashes.size()), |
| 151 | Counter::kIsIterationInvariantRate); |
| 152 | } |
| 153 | |
| 154 | template <typename MapType> |
| 155 | void BM_HashMap_InsertTraceStrings(benchmark::State& state) { |
| 156 | std::vector<uint64_t> hashes = LoadTraceStrings(state); |
| 157 | for (auto _ : state) { |
| 158 | MapType mapz; |
| 159 | for (uint64_t hash : hashes) |
| 160 | mapz.insert({hash, 42}); |
| 161 | |
| 162 | benchmark::ClobberMemory(); |
| 163 | state.counters["uniq"] = Counter(static_cast<double>(mapz.size())); |
| 164 | } |
| 165 | state.counters["tot"] = Counter(static_cast<double>(hashes.size()), |
| 166 | Counter::kIsIterationInvariant); |
| 167 | state.counters["rate"] = Counter(static_cast<double>(hashes.size()), |
| 168 | Counter::kIsIterationInvariantRate); |
| 169 | } |
| 170 | |
| 171 | template <typename MapType> |
| 172 | void BM_HashMap_TraceTids(benchmark::State& state) { |
| 173 | std::vector<std::pair<char, int>> ops_and_tids; |
| 174 | { |
| 175 | base::ScopedFstream f(fopen("/tmp/tids", "re")); |
| 176 | if (!f) { |
| 177 | // This test requires a large (800MB) test file. It's not checked into the |
| 178 | // repository's //test/data because it would slow down all developers for |
| 179 | // a marginal benefit. |
| 180 | state.SkipWithError( |
| 181 | "Please run `curl -Lo /tmp/tids " |
| 182 | "https://storage.googleapis.com/perfetto/test_datalong_trace_tids.txt" |
| 183 | "` and try again."); |
| 184 | return; |
| 185 | } |
| 186 | char op; |
| 187 | int tid; |
| 188 | while (fscanf(*f, "%c %d\n", &op, &tid) == 2) |
| 189 | ops_and_tids.emplace_back(op, tid); |
| 190 | } |
| 191 | |
| 192 | for (auto _ : state) { |
| 193 | MapType mapz; |
| 194 | for (const auto& ops_and_tid : ops_and_tids) { |
| 195 | if (ops_and_tid.first == '[') { |
| 196 | mapz[ops_and_tid.second]++; |
| 197 | } else { |
| 198 | mapz.insert({ops_and_tid.second, 0}); |
| 199 | } |
| 200 | } |
| 201 | |
| 202 | benchmark::ClobberMemory(); |
| 203 | state.counters["uniq"] = Counter(static_cast<double>(mapz.size())); |
| 204 | } |
| 205 | state.counters["rate"] = Counter(static_cast<double>(ops_and_tids.size()), |
| 206 | Counter::kIsIterationInvariantRate); |
| 207 | } |
| 208 | |
| 209 | template <typename MapType> |
| 210 | void BM_HashMap_InsertRandInts(benchmark::State& state) { |
| 211 | std::minstd_rand0 rng(0); |
| 212 | std::vector<size_t> keys(static_cast<size_t>(num_samples())); |
| 213 | std::shuffle(keys.begin(), keys.end(), rng); |
| 214 | for (auto _ : state) { |
| 215 | MapType mapz; |
| 216 | for (const auto key : keys) |
| 217 | mapz.insert({key, key}); |
| 218 | benchmark::DoNotOptimize(mapz); |
| 219 | benchmark::ClobberMemory(); |
| 220 | } |
| 221 | state.counters["insertions"] = Counter(static_cast<double>(keys.size()), |
| 222 | Counter::kIsIterationInvariantRate); |
| 223 | } |
| 224 | |
| 225 | // This test is performs insertions on integers that are designed to create |
| 226 | // lot of clustering on the same small set of buckets. |
| 227 | // This covers the unlucky case of using a map with a poor hashing function. |
| 228 | template <typename MapType> |
| 229 | void BM_HashMap_InsertCollidingInts(benchmark::State& state) { |
| 230 | std::vector<size_t> keys; |
| 231 | const size_t kNumSamples = num_samples(); |
| 232 | |
| 233 | // Generates numbers that are all distinct from each other, but that are |
| 234 | // designed to collide on the same buckets. |
| 235 | constexpr size_t kShift = 8; // Collide on the same 2^8 = 256 buckets. |
| 236 | for (size_t i = 0; i < kNumSamples; i++) { |
| 237 | size_t bucket = i & ((1 << kShift) - 1); // [0, 256]. |
| 238 | size_t multiplier = i >> kShift; // 0,0,0... 1,1,1..., 2,2,2... |
| 239 | size_t key = 8192 * multiplier + bucket; |
| 240 | keys.push_back(key); |
| 241 | } |
| 242 | for (auto _ : state) { |
| 243 | MapType mapz; |
| 244 | for (const size_t key : keys) |
| 245 | mapz.insert({key, key}); |
| 246 | benchmark::DoNotOptimize(mapz); |
| 247 | benchmark::ClobberMemory(); |
| 248 | } |
| 249 | state.counters["insertions"] = Counter(static_cast<double>(keys.size()), |
| 250 | Counter::kIsIterationInvariantRate); |
| 251 | } |
| 252 | |
| 253 | // Unlike the previous benchmark, here integers don't just collide on the same |
| 254 | // buckets, they have a large number of duplicates with the same values. |
| 255 | // Most of those insertions are no-ops. This tests the ability of the hashmap |
| 256 | // to deal with cases where the hash function is good but the insertions contain |
| 257 | // lot of dupes (e.g. dealing with pids). |
| 258 | template <typename MapType> |
| 259 | void BM_HashMap_InsertDupeInts(benchmark::State& state) { |
| 260 | std::vector<size_t> keys; |
| 261 | const size_t kNumSamples = num_samples(); |
| 262 | |
| 263 | for (size_t i = 0; i < kNumSamples; i++) |
| 264 | keys.push_back(i % 16384); |
| 265 | |
| 266 | for (auto _ : state) { |
| 267 | MapType mapz; |
| 268 | for (const size_t key : keys) |
| 269 | mapz.insert({key, key}); |
| 270 | benchmark::DoNotOptimize(mapz); |
| 271 | benchmark::ClobberMemory(); |
| 272 | } |
| 273 | state.counters["insertions"] = Counter(static_cast<double>(keys.size()), |
| 274 | Counter::kIsIterationInvariantRate); |
| 275 | } |
| 276 | |
| 277 | template <typename MapType> |
| 278 | void BM_HashMap_LookupRandInts(benchmark::State& state) { |
| 279 | std::minstd_rand0 rng(0); |
| 280 | std::vector<size_t> keys(static_cast<size_t>(num_samples())); |
| 281 | std::shuffle(keys.begin(), keys.end(), rng); |
| 282 | |
| 283 | MapType mapz; |
| 284 | for (const size_t key : keys) |
| 285 | mapz.insert({key, key}); |
| 286 | |
| 287 | for (auto _ : state) { |
| 288 | int64_t total = 0; |
| 289 | for (const size_t key : keys) { |
| 290 | auto it = mapz.find(static_cast<uint64_t>(key)); |
| 291 | PERFETTO_CHECK(it != mapz.end()); |
| 292 | total += it->second; |
| 293 | } |
| 294 | benchmark::DoNotOptimize(total); |
| 295 | benchmark::ClobberMemory(); |
| 296 | state.counters["sum"] = Counter(static_cast<double>(total)); |
| 297 | } |
| 298 | state.counters["lookups"] = Counter(static_cast<double>(keys.size()), |
| 299 | Counter::kIsIterationInvariantRate); |
| 300 | } |
| 301 | |
| 302 | } // namespace |
| 303 | |
| 304 | using Ours_LinearProbing = |
| 305 | Ours<uint64_t, uint64_t, AlreadyHashed<uint64_t>, LinearProbe>; |
| 306 | using Ours_QuadProbing = |
| 307 | Ours<uint64_t, uint64_t, AlreadyHashed<uint64_t>, QuadraticProbe>; |
| 308 | using Ours_QuadCompProbing = |
| 309 | Ours<uint64_t, uint64_t, AlreadyHashed<uint64_t>, QuadraticHalfProbe>; |
| 310 | using StdUnorderedMap = |
| 311 | std::unordered_map<uint64_t, uint64_t, AlreadyHashed<uint64_t>>; |
| 312 | |
| 313 | #if defined(PERFETTO_HASH_MAP_COMPARE_THIRD_PARTY_LIBS) |
| 314 | using RobinMap = tsl::robin_map<uint64_t, uint64_t, AlreadyHashed<uint64_t>>; |
| 315 | using AbslFlatHashMap = |
| 316 | absl::flat_hash_map<uint64_t, uint64_t, AlreadyHashed<uint64_t>>; |
| 317 | using FollyF14FastMap = |
| 318 | folly::F14FastMap<uint64_t, uint64_t, AlreadyHashed<uint64_t>>; |
| 319 | #endif |
| 320 | |
| 321 | BENCHMARK(BM_HashMap_InsertTraceStrings_AppendOnly); |
| 322 | BENCHMARK_TEMPLATE(BM_HashMap_InsertTraceStrings, Ours_LinearProbing); |
| 323 | BENCHMARK_TEMPLATE(BM_HashMap_InsertTraceStrings, Ours_QuadProbing); |
| 324 | BENCHMARK_TEMPLATE(BM_HashMap_InsertTraceStrings, StdUnorderedMap); |
| 325 | #if defined(PERFETTO_HASH_MAP_COMPARE_THIRD_PARTY_LIBS) |
| 326 | BENCHMARK_TEMPLATE(BM_HashMap_InsertTraceStrings, RobinMap); |
| 327 | BENCHMARK_TEMPLATE(BM_HashMap_InsertTraceStrings, AbslFlatHashMap); |
| 328 | BENCHMARK_TEMPLATE(BM_HashMap_InsertTraceStrings, FollyF14FastMap); |
| 329 | #endif |
| 330 | |
| 331 | #define TID_ARGS int, uint64_t, std::hash<int> |
| 332 | BENCHMARK_TEMPLATE(BM_HashMap_TraceTids, Ours<TID_ARGS, LinearProbe>); |
| 333 | BENCHMARK_TEMPLATE(BM_HashMap_TraceTids, Ours<TID_ARGS, QuadraticProbe>); |
| 334 | BENCHMARK_TEMPLATE(BM_HashMap_TraceTids, Ours<TID_ARGS, QuadraticHalfProbe>); |
| 335 | BENCHMARK_TEMPLATE(BM_HashMap_TraceTids, std::unordered_map<TID_ARGS>); |
| 336 | #if defined(PERFETTO_HASH_MAP_COMPARE_THIRD_PARTY_LIBS) |
| 337 | BENCHMARK_TEMPLATE(BM_HashMap_TraceTids, tsl::robin_map<TID_ARGS>); |
| 338 | BENCHMARK_TEMPLATE(BM_HashMap_TraceTids, absl::flat_hash_map<TID_ARGS>); |
| 339 | BENCHMARK_TEMPLATE(BM_HashMap_TraceTids, folly::F14FastMap<TID_ARGS>); |
| 340 | #endif |
| 341 | |
| 342 | BENCHMARK_TEMPLATE(BM_HashMap_InsertRandInts, Ours_LinearProbing); |
| 343 | BENCHMARK_TEMPLATE(BM_HashMap_InsertRandInts, Ours_QuadProbing); |
| 344 | BENCHMARK_TEMPLATE(BM_HashMap_InsertRandInts, StdUnorderedMap); |
| 345 | #if defined(PERFETTO_HASH_MAP_COMPARE_THIRD_PARTY_LIBS) |
| 346 | BENCHMARK_TEMPLATE(BM_HashMap_InsertRandInts, RobinMap); |
| 347 | BENCHMARK_TEMPLATE(BM_HashMap_InsertRandInts, AbslFlatHashMap); |
| 348 | BENCHMARK_TEMPLATE(BM_HashMap_InsertRandInts, FollyF14FastMap); |
| 349 | #endif |
| 350 | |
| 351 | BENCHMARK_TEMPLATE(BM_HashMap_InsertCollidingInts, Ours_LinearProbing); |
| 352 | BENCHMARK_TEMPLATE(BM_HashMap_InsertCollidingInts, Ours_QuadProbing); |
| 353 | BENCHMARK_TEMPLATE(BM_HashMap_InsertCollidingInts, Ours_QuadCompProbing); |
| 354 | BENCHMARK_TEMPLATE(BM_HashMap_InsertCollidingInts, StdUnorderedMap); |
| 355 | #if defined(PERFETTO_HASH_MAP_COMPARE_THIRD_PARTY_LIBS) |
| 356 | BENCHMARK_TEMPLATE(BM_HashMap_InsertCollidingInts, RobinMap); |
| 357 | BENCHMARK_TEMPLATE(BM_HashMap_InsertCollidingInts, AbslFlatHashMap); |
| 358 | BENCHMARK_TEMPLATE(BM_HashMap_InsertCollidingInts, FollyF14FastMap); |
| 359 | #endif |
| 360 | |
| 361 | BENCHMARK_TEMPLATE(BM_HashMap_InsertDupeInts, Ours_LinearProbing); |
| 362 | BENCHMARK_TEMPLATE(BM_HashMap_InsertDupeInts, Ours_QuadProbing); |
| 363 | BENCHMARK_TEMPLATE(BM_HashMap_InsertDupeInts, Ours_QuadCompProbing); |
| 364 | BENCHMARK_TEMPLATE(BM_HashMap_InsertDupeInts, StdUnorderedMap); |
| 365 | #if defined(PERFETTO_HASH_MAP_COMPARE_THIRD_PARTY_LIBS) |
| 366 | BENCHMARK_TEMPLATE(BM_HashMap_InsertDupeInts, RobinMap); |
| 367 | BENCHMARK_TEMPLATE(BM_HashMap_InsertDupeInts, AbslFlatHashMap); |
| 368 | BENCHMARK_TEMPLATE(BM_HashMap_InsertDupeInts, FollyF14FastMap); |
| 369 | #endif |
| 370 | |
| 371 | BENCHMARK_TEMPLATE(BM_HashMap_LookupRandInts, Ours_LinearProbing); |
| 372 | BENCHMARK_TEMPLATE(BM_HashMap_LookupRandInts, Ours_QuadProbing); |
| 373 | BENCHMARK_TEMPLATE(BM_HashMap_LookupRandInts, StdUnorderedMap); |
| 374 | #if defined(PERFETTO_HASH_MAP_COMPARE_THIRD_PARTY_LIBS) |
| 375 | BENCHMARK_TEMPLATE(BM_HashMap_LookupRandInts, RobinMap); |
| 376 | BENCHMARK_TEMPLATE(BM_HashMap_LookupRandInts, AbslFlatHashMap); |
| 377 | BENCHMARK_TEMPLATE(BM_HashMap_LookupRandInts, FollyF14FastMap); |
| 378 | #endif |