package runtime_events_tools
Tools for the runtime events tracing system in OCaml
Install
Dune Dependency
Authors
Maintainers
Sources
runtime_events_tools-0.5.0.tbz
sha256=818258e2f81d42327cee846dda9fec5a863e926152903be3f4e5c686ee660270
sha512=50c5ecdae4a73c4f26d68da21265c8ee2731bff76445db9e637237793d7024a272f78f6a57650e51c70a459843a656c19d5ee79d2e5aeed0460983adb67fe548
Description
Various tools for the runtime events tracing system in OCaml
Published: 05 Oct 2023
README
Runtime events tools
A collection of observability tools around the runtime events tracing system introduced in OCaml 5.0.
olly
olly provides a number of sub-commands.
gc-stats
olly gc-stats will report the GC running time and GC tail latency profile of an OCaml executable.
| Metric | Description |
|---|---|
| Wall time | Real execution time of the program |
| CPU time | Total CPU time across all domains |
| GC time | Total time spent by the program performing garbage collection (major and minor) |
| GC overhead | Percentage of time taken up by GC against the total execution time |
| GC time per domain | Time spent by every domain performing garbage collection (major and minor cycles). Domains are reported with their domain ID (e.g. Domain0) |
| GC latency profile | Mean, standard deviation and percentile latency profile of GC events. |
$ olly gc-stats 'binarytrees.exe 19' # Use quotes for commands with arguments
Execution times:
Wall time (s): 2.01
CPU time (s): 5.73
GC time (s): 3.15
GC overhead (% of CPU time): 55.00%
GC time per domain (s):
Domain0: 1.15
Domain1: 0.99
Domain2: 1.01
GC latency profile:
#[Mean (ms): 0.88, Stddev (ms): 1.67]
#[Min (ms): 0.00, max (ms): 13.21]
Percentile Latency (ms)
25.0000 0.01
50.0000 0.04
60.0000 0.13
70.0000 0.45
75.0000 0.79
80.0000 1.53
85.0000 2.46
90.0000 3.46
95.0000 4.38
96.0000 5.07
97.0000 5.87
98.0000 6.45
99.0000 7.08
99.9000 11.20
99.9900 13.21
99.9990 13.21
99.9999 13.21
100.0000 13.21
$ olly gc-stats 'menhir -v --table sysver.mly' # Use quotes for commands with arguments
<snip>
Execution times:
Wall time (s): 60.88
CPU time (s): 60.88
GC time (s): 7.30
GC overhead (% of CPU time): 11.99%
GC time per domain (s):
Domain0: 7.30
GC latency profile:
#[Mean (ms): 0.10, Stddev (ms): 0.43]
#[Min (ms): 0.00, max (ms): 39.16]
Percentile Latency (ms)
25.0000 0.00
50.0000 0.00
60.0000 0.00
70.0000 0.00
75.0000 0.00
80.0000 0.00
85.0000 0.01
90.0000 0.26
95.0000 0.69
96.0000 0.88
97.0000 1.04
98.0000 1.30
99.0000 1.91
99.9000 4.56
99.9900 8.31
99.9990 9.83
99.9999 39.16
100.0000 39.16
trace
olly trace will record the runtime trace log in Fuchsia trace format or Chrome tracing format . Format of the trace file can be specified with the --format option. The default is Fuchsia trace format.
$ olly trace --format=fuchsia menhir_sysver.trace 'menhir -v --table sysver.mly' # Fuchsia trace format
<snip>
$ ls menhir_sysver.trace
menhir_sysver.trace
$ olly trace --format=json menhir_sysver.trace 'menhir -v --table sysver.mly' # Chrome tracing format
<snip>
$ ls menhir_sysver.trace
menhir_sysver.trace
Traces in either formats can be viewed in perfetto trace viewer. Chrome format trace can also be viewed in chrome://tracing in chromium-based browsers.
Dependencies
The library depends on hdr_histogram_ocaml.