1CARGO-BENCH(1) General Commands Manual CARGO-BENCH(1)
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6 cargo-bench - Execute benchmarks of a package
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9 cargo bench [options] [benchname] [-- bench-options]
10
12 Compile and execute benchmarks.
13 The benchmark filtering argument benchname and all the arguments
15 following the two dashes (--) are passed to the benchmark binaries and
16 thus to libtest (rustc's built in unit-test and micro-benchmarking
17 framework). If you are passing arguments to both Cargo and the binary,
18 the ones after -- go to the binary, the ones before go to Cargo. For
19 details about libtest's arguments see the output of cargo bench --
20 --help and check out the rustc book's chapter on how tests work at
21 <https://doc.rust-lang.org/rustc/tests/index.html>.
22 As an example, this will run only the benchmark named foo (and skip
24 other similarly named benchmarks like foobar):
25 cargo bench -- foo --exact
27 Benchmarks are built with the --test option to rustc which creates an
29 executable with a main function that automatically runs all functions
30 annotated with the #[bench] attribute. Cargo passes the --bench flag to
31 the test harness to tell it to run only benchmarks.
32 The libtest harness may be disabled by setting harness = false in the
34 target manifest settings, in which case your code will need to provide
35 its own main function to handle running benchmarks.
36 Note: The #[bench] attribute
38 <https://doc.rust-lang.org/nightly/unstable-book/library-features/test.html>
39 is currently unstable and only available on the nightly channel
40 <https://doc.rust-lang.org/book/appendix-07-nightly-rust.html>.
41 There are some packages available on crates.io
42 <https://crates.io/keywords/benchmark> that may help with
43 running benchmarks on the stable channel, such as Criterion
44 <https://crates.io/crates/criterion>.
45 By default, cargo bench uses the bench profile
47 <https://doc.rust-lang.org/cargo/reference/profiles.html#bench>, which
48 enables optimizations and disables debugging information. If you need
49 to debug a benchmark, you can use the --profile=dev command-line option
50 to switch to the dev profile. You can then run the debug-enabled
51 benchmark within a debugger.
52
54 Benchmark Options
55 --no-run
56 Compile, but don't run benchmarks.
57 --no-fail-fast
59 Run all benchmarks regardless of failure. Without this flag, Cargo
60 will exit after the first executable fails. The Rust test harness
61 will run all benchmarks within the executable to completion, this
62 flag only applies to the executable as a whole.
63 Package Selection
65 By default, when no package selection options are given, the packages
66 selected depend on the selected manifest file (based on the current
67 working directory if --manifest-path is not given). If the manifest is
68 the root of a workspace then the workspaces default members are
69 selected, otherwise only the package defined by the manifest will be
70 selected.
71 The default members of a workspace can be set explicitly with the
73 workspace.default-members key in the root manifest. If this is not set,
74 a virtual workspace will include all workspace members (equivalent to
75 passing --workspace), and a non-virtual workspace will include only the
76 root crate itself.
77 -p spec..., --package spec...
79 Benchmark only the specified packages. See cargo-pkgid(1) for the
80 SPEC format. This flag may be specified multiple times and supports
81 common Unix glob patterns like *, ? and []. However, to avoid your
82 shell accidentally expanding glob patterns before Cargo handles
83 them, you must use single quotes or double quotes around each
84 pattern.
85 --workspace
87 Benchmark all members in the workspace.
88 --all
90 Deprecated alias for --workspace.
91 --exclude SPEC...
93 Exclude the specified packages. Must be used in conjunction with
94 the --workspace flag. This flag may be specified multiple times and
95 supports common Unix glob patterns like *, ? and []. However, to
96 avoid your shell accidentally expanding glob patterns before Cargo
97 handles them, you must use single quotes or double quotes around
98 each pattern.
99 Target Selection
101 When no target selection options are given, cargo bench will build the
102 following targets of the selected packages:
103 • lib — used to link with binaries and benchmarks
105 • bins (only if benchmark targets are built and required features are
107 available)
108 • lib as a benchmark
110 • bins as benchmarks
112 • benchmark targets
114 The default behavior can be changed by setting the bench flag for the
116 target in the manifest settings. Setting examples to bench = true will
117 build and run the example as a benchmark. Setting targets to bench =
118 false will stop them from being benchmarked by default. Target
119 selection options that take a target by name ignore the bench flag and
120 will always benchmark the given target.
121 Passing target selection flags will benchmark only the specified
123 targets.
124 Note that --bin, --example, --test and --bench flags also support
126 common Unix glob patterns like *, ? and []. However, to avoid your
127 shell accidentally expanding glob patterns before Cargo handles them,
128 you must use single quotes or double quotes around each glob pattern.
129 --lib
131 Benchmark the package's library.
132 --bin name...
134 Benchmark the specified binary. This flag may be specified multiple
135 times and supports common Unix glob patterns.
136 --bins
138 Benchmark all binary targets.
139 --example name...
141 Benchmark the specified example. This flag may be specified
142 multiple times and supports common Unix glob patterns.
143 --examples
145 Benchmark all example targets.
146 --test name...
148 Benchmark the specified integration test. This flag may be
149 specified multiple times and supports common Unix glob patterns.
150 --tests
152 Benchmark all targets in test mode that have the test = true
153 manifest flag set. By default this includes the library and
154 binaries built as unittests, and integration tests. Be aware that
155 this will also build any required dependencies, so the lib target
156 may be built twice (once as a unittest, and once as a dependency
157 for binaries, integration tests, etc.). Targets may be enabled or
158 disabled by setting the test flag in the manifest settings for the
159 target.
160 --bench name...
162 Benchmark the specified benchmark. This flag may be specified
163 multiple times and supports common Unix glob patterns.
164 --benches
166 Benchmark all targets in benchmark mode that have the bench = true
167 manifest flag set. By default this includes the library and
168 binaries built as benchmarks, and bench targets. Be aware that this
169 will also build any required dependencies, so the lib target may be
170 built twice (once as a benchmark, and once as a dependency for
171 binaries, benchmarks, etc.). Targets may be enabled or disabled by
172 setting the bench flag in the manifest settings for the target.
173 --all-targets
175 Benchmark all targets. This is equivalent to specifying --lib
176 --bins --tests --benches --examples.
177 Feature Selection
179 The feature flags allow you to control which features are enabled. When
180 no feature options are given, the default feature is activated for
181 every selected package.
182 See the features documentation
184 <https://doc.rust-lang.org/cargo/reference/features.html#command-line-feature-options>
185 for more details.
186 -F features, --features features
188 Space or comma separated list of features to activate. Features of
189 workspace members may be enabled with package-name/feature-name
190 syntax. This flag may be specified multiple times, which enables
191 all specified features.
192 --all-features
194 Activate all available features of all selected packages.
195 --no-default-features
197 Do not activate the default feature of the selected packages.
198 Compilation Options
200 --target triple
201 Benchmark for the given architecture. The default is the host
202 architecture. The general format of the triple is
203 <arch><sub>-<vendor>-<sys>-<abi>. Run rustc --print target-list for
204 a list of supported targets.
205 This may also be specified with the build.target config value
207 <https://doc.rust-lang.org/cargo/reference/config.html>.
208 Note that specifying this flag makes Cargo run in a different mode
210 where the target artifacts are placed in a separate directory. See
211 the build cache
212 <https://doc.rust-lang.org/cargo/guide/build-cache.html>
213 documentation for more details.
214 --profile name
216 Benchmark with the given profile. See the the reference
217 <https://doc.rust-lang.org/cargo/reference/profiles.html> for more
218 details on profiles.
219 --ignore-rust-version
221 Benchmark the target even if the selected Rust compiler is older
222 than the required Rust version as configured in the project's
223 rust-version field.
224 --timings=fmts
226 Output information how long each compilation takes, and track
227 concurrency information over time. Accepts an optional
228 comma-separated list of output formats; --timings without an
229 argument will default to --timings=html. Specifying an output
230 format (rather than the default) is unstable and requires
231 -Zunstable-options. Valid output formats:
232 • html: Write a human-readable file cargo-timing.html to the
234 target/cargo-timings directory with a report of the
235 compilation. Also write a report to the same directory with a
236 timestamp in the filename if you want to look at older runs.
237 HTML output is suitable for human consumption only, and does
238 not provide machine-readable timing data.
239 • json (unstable, requires -Zunstable-options): Emit
241 machine-readable JSON information about timing information.
242 Output Options
244 --target-dir directory
245 Directory for all generated artifacts and intermediate files. May
246 also be specified with the CARGO_TARGET_DIR environment variable,
247 or the build.target-dir config value
248 <https://doc.rust-lang.org/cargo/reference/config.html>. Defaults
249 to target in the root of the workspace.
250 Display Options
252 By default the Rust test harness hides output from benchmark execution
253 to keep results readable. Benchmark output can be recovered (e.g., for
254 debugging) by passing --nocapture to the benchmark binaries:
255 cargo bench -- --nocapture
257 -v, --verbose
259 Use verbose output. May be specified twice for "very verbose"
260 output which includes extra output such as dependency warnings and
261 build script output. May also be specified with the term.verbose
262 config value
263 <https://doc.rust-lang.org/cargo/reference/config.html>.
264 -q, --quiet
266 Do not print cargo log messages. May also be specified with the
267 term.quiet config value
268 <https://doc.rust-lang.org/cargo/reference/config.html>.
269 --color when
271 Control when colored output is used. Valid values:
272 • auto (default): Automatically detect if color support is
274 available on the terminal.
275 • always: Always display colors.
277 • never: Never display colors.
279 May also be specified with the term.color config value
281 <https://doc.rust-lang.org/cargo/reference/config.html>.
282 --message-format fmt
284 The output format for diagnostic messages. Can be specified
285 multiple times and consists of comma-separated values. Valid
286 values:
287 • human (default): Display in a human-readable text format.
289 Conflicts with short and json.
290 • short: Emit shorter, human-readable text messages. Conflicts
292 with human and json.
293 • json: Emit JSON messages to stdout. See the reference
295 <https://doc.rust-lang.org/cargo/reference/external-tools.html#json-messages>
296 for more details. Conflicts with human and short.
297 • json-diagnostic-short: Ensure the rendered field of JSON
299 messages contains the "short" rendering from rustc. Cannot be
300 used with human or short.
301 • json-diagnostic-rendered-ansi: Ensure the rendered field of JSON
303 messages contains embedded ANSI color codes for respecting
304 rustc's default color scheme. Cannot be used with human or
305 short.
306 • json-render-diagnostics: Instruct Cargo to not include rustc
308 diagnostics in in JSON messages printed, but instead Cargo
309 itself should render the JSON diagnostics coming from rustc.
310 Cargo's own JSON diagnostics and others coming from rustc are
311 still emitted. Cannot be used with human or short.
312 Manifest Options
314 --manifest-path path
315 Path to the Cargo.toml file. By default, Cargo searches for the
316 Cargo.toml file in the current directory or any parent directory.
317 --frozen, --locked
319 Either of these flags requires that the Cargo.lock file is
320 up-to-date. If the lock file is missing, or it needs to be updated,
321 Cargo will exit with an error. The --frozen flag also prevents
322 Cargo from attempting to access the network to determine if it is
323 out-of-date.
324 These may be used in environments where you want to assert that the
326 Cargo.lock file is up-to-date (such as a CI build) or want to avoid
327 network access.
328 --offline
330 Prevents Cargo from accessing the network for any reason. Without
331 this flag, Cargo will stop with an error if it needs to access the
332 network and the network is not available. With this flag, Cargo
333 will attempt to proceed without the network if possible.
334 Beware that this may result in different dependency resolution than
336 online mode. Cargo will restrict itself to crates that are
337 downloaded locally, even if there might be a newer version as
338 indicated in the local copy of the index. See the cargo-fetch(1)
339 command to download dependencies before going offline.
340 May also be specified with the net.offline config value
342 <https://doc.rust-lang.org/cargo/reference/config.html>.
343 Common Options
345 +toolchain
346 If Cargo has been installed with rustup, and the first argument to
347 cargo begins with +, it will be interpreted as a rustup toolchain
348 name (such as +stable or +nightly). See the rustup documentation
349 <https://rust-lang.github.io/rustup/overrides.html> for more
350 information about how toolchain overrides work.
351 -h, --help
353 Prints help information.
354 -Z flag
356 Unstable (nightly-only) flags to Cargo. Run cargo -Z help for
357 details.
358 Miscellaneous Options
360 The --jobs argument affects the building of the benchmark executable
361 but does not affect how many threads are used when running the
362 benchmarks. The Rust test harness runs benchmarks serially in a single
363 thread.
364 -j N, --jobs N
366 Number of parallel jobs to run. May also be specified with the
367 build.jobs config value
368 <https://doc.rust-lang.org/cargo/reference/config.html>. Defaults
369 to the number of CPUs.
370 --keep-going
372 Build as many crates in the dependency graph as possible, rather
373 than aborting the build on the first one that fails to build.
374 Unstable, requires -Zunstable-options.
375
377 See the reference
378 <https://doc.rust-lang.org/cargo/reference/environment-variables.html>
379 for details on environment variables that Cargo reads.
380
382 • 0: Cargo succeeded.
383 • 101: Cargo failed to complete.
385
387 1. Build and execute all the benchmarks of the current package:
388 cargo bench
390 2. Run only a specific benchmark within a specific benchmark target:
392 cargo bench --bench bench_name -- modname::some_benchmark
394
396 cargo(1), cargo-test(1)
397 CARGO-BENCH(1)