Tracing and monitoring tools for Linux.
Allows tracing of:
- Block and character device i/o latency
- Run queue scheduling latency
- File system latency
- TCP packet latency
And monitoring of:
- CPU utilization %
- Virtual memory utilization %
These metrics can be exported in a columnar, CSV, or JSON format.
When written as a CSV file, the output may be plotted using fl-plot:
fl --all --output-file /tmp/trace.csv --pid 42
# ...
fl-plot -i /tmp/trace.csv -o /tmp/trace.htmlThe plot is a standalone HTML file which can be opened in a browser.
This is a library as well as a few command-line tools.
Usage: fl [OPTIONS]
Options:
-a, --all
Enable all tracing and monitoring tools
--bio-lat
Enable block and character device i/o latency tracing
--rq-lat
Enable run queue latency tracing
--fs-lat
Enable file system latency tracing
--tcp-pkt-lat
Enable TCP packet latency tracing
--cpu-pct
Enable cpu utilization % monitoring
--mem-pct
Enable virtual memory utilization % monitoring
-p, --pid <PID>
Process ID to trace, or 0 for everything [default: 0]
--tgid <TGID>
Thread ID to trace [default: 0]
-l, --min-lat-us <MIN_LAT_US>
Trace latency higher than this value [default: 10000]
-i, --reporting-interval-ms <REPORTING_INTERVAL_MS>
For monitoring tools, stats will be reported at this interval [default: 1000]
-f, --output-format <OUTPUT_FORMAT>
Some output styles are better for humans (columnar), others for machines [default: columnar] [possible values: columnar, csv, json]
--duration-format <DURATION_FORMAT>
Output format for the duration since this program's start [default: usecs] [possible values: hh-mm-ss, hh-mm-ss-mss, usecs]
-o, --output-file <OUTPUT_FILE>
Write events to this file, if present, or to standard output if not given
--no-header
Omit the header (tool/time/task/pid/value) as the first line of output
--just-header
Show a header and exit ('-V, --version' has precedence)
-h, --help
Print help (see more with '--help')
-V, --version
Print version