6 releases (breaking)
0.7.0 | Sep 16, 2024 |
---|---|
0.6.0 | Jul 31, 2024 |
0.4.0 | Jun 12, 2024 |
0.3.0 | Apr 29, 2024 |
0.1.0 | Feb 12, 2024 |
#51 in Profiling
823 downloads per month
700KB
12K
SLoC
tracing-profile
This library implements subscribers for the tracing
crate that facilitate
profiling of one-shot program executions. That is, this is not intended for profiling of long-running programs.
tracing-profile
depends on tracing-subscriber
and
implements layers that measure, record, and display timing information in the span graph. The implemented
tracing_subscriber::Layer
records the time a span took to execute, along with any user supplied metadata and
information necessary to construct a span graph from the resulting logs.
Note that if #[tracing::instrument]
is used, the skip_all
argument is recommended. Omitting this will result in all
the function arguments being included as fields.
Usage
The library exposes two layers that output the information in different ways.
Feature flags
perf_counters
enablesPrintPerfCountersLayer
layer. Currently performance counters work for Linux only.
CsvLayer
The CsvLayer
writes profiling information to a CSV file, which can be analyzed later by reconstructing the span graph.
$ cargo test
$ cat /tmp/output.csv
id,parent_id,elapsed_ns,span_name,file_name,call_depth,metadata
2,1,22837,child span1,src/lib.rs,2,{"field1":"value1"}
4,3,9255,child span3,src/lib.rs,3,{"field3":"value3"}
5,3,7135,child span4,src/lib.rs,3,{"field4":"value4"}
3,1,119802,child span2,src/lib.rs,2,{"field2":"value2"}
1,0,287881,root span,src/lib.rs,1,{}
PrintTreeLayer
The PrintTreeLayer
processes the profiling information in the running process and prints the timing information in a
human-readable format. The output structures the span graph as a tree.
$ cargo test -- --nocapture
root span [ 112.67µs | 100.00% ]
├── child span1 [ 2.63µs | 2.33% ] { field1 = value1 }
└── child span2 [ 64.29µs | 57.06% ] { field2 = value2 }
├── child span3 [ 1.88µs | 1.66% ] { field3 = value3 }
└── child span4 [ 1.67µs | 1.48% ] { field4 = value4 }
PrintPerfCountersLayer
The PrintPerfCountersLayer
at the construction receives a vector of events (perf_event::events::Event
) and their names. During execution for each span the number of the given events of each type is summed. The results are printed to the standard output in a form of a table.
perf_counters
crate feature enables this functionality.
$ cargo test -- --nocapture
child span4:
instructions: 44142
cycles: 34398
child span3:
instructions: 44132
cycles: 37674
child span2:
instructions: 282256
cycles: 272064
child span1:
instructions: 49107
cycles: 112554
root span:
instructions: 661552
cycles: 738894
IttApiLayer
The IttApiLayer
adds one ittapi::Task
for each span at runtime allowing observing spans in Intel VTune profiler. See ITT API documentation for reference.
ittapi
crate feature enables this functionality.
Perfetto layer
The Perfetto
layer
- for each tracing span span creates a single Perfetto event with the same lifetime
- for each event that has
counter
property set to true updates the corresponding Perfetto counter value using thevalue
property of the event.
Example Test
fn make_spans() {
let span = debug_span!("root span");
let _scope1 = span.enter();
// child spans 1 and 2 are siblings
let span2 = debug_span!("child span1", field1 = "value1");
let scope2 = span2.enter();
drop(scope2);
let span3 = debug_span!("child span2", field2 = "value2");
let _scope3 = span3.enter();
// child spans 3 and 4 are siblings
let span = debug_span!("child span3", field3 = "value3");
let scope = span.enter();
drop(scope);
let span = debug_span!("child span4", field4 = "value4");
let scope = span.enter();
drop(scope);
}
#[test]
fn all_layers() {
tracing_subscriber::registry()
.with(PrintTreeLayer::default())
.with(CsvLayer::new("/tmp/output.csv"))
.init();
make_spans();
}
Configuration
Using PrintTreeConfig
you can configure color and aggregation/hiding thresholds.
#[test]
fn all_layers() {
tracing_subscriber::registry()
.with(PrintTreeLayer::new(PrintTreeConfig {
attention_above_percent: 25.0,
relevant_above_percent: 2.5,
hide_below_percent: 1.0,
display_unaccounted: false
}))
.with(CsvLayer::new("/tmp/output.csv"))
.init();
make_spans();
}
Authors
tracing-profile
is developed and maintained by Ulvetanna.
License
MIT License
Copyright (c) 2024 Ulvetanna, Inc
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Dependencies
~3.5MB
~63K SLoC