romenskiy2012/curl
1
0
Fork 0
mirror of https://github.com/curl/curl.git synced 2026-07-26 21:37:16 +03:00
Code Issues Projects Releases Packages Wiki Activity

scorecard: add perf support on linux

Browse source 
When calling scorecard with --flame to produce a flamegraph, use
"perf" on linux platforms to do the measurements. Update the scorecard
documentation about it.

Closes #19058
This commit is contained in:
Stefan Eissing 2025-10-14 14:39:50 +02:00 • committed by Daniel Stenberg
parent 4c7507daf9
commit 1ea99afdc7
No known key found for this signature in database
GPG key ID: 5CC908FDB71E12C2
3 changed files with 119 additions and 46 deletions
Download patch file Download diff file Expand all files Collapse all files

19
docs/internals/SCORECARD.md
View file

@ -59,15 +59,9 @@ If you have configured curl with `--with-test-danted=<danted-path>` for a
with arguments `--socks4` or `--socks5` to test performance with a SOCKS proxy
involved. (Note: this does not work for HTTP/3)
## dtrace
With the `--dtrace` option, scorecard produces a dtrace sample of the user stacks in `tests/http/gen/curl/curl.user_stacks`. On many platforms, `dtrace` requires **special permissions**. It is therefore invoked via `sudo` and you should make sure that sudo works for the run without prompting for a password.
Note: the file is the trace of the last curl invocation by scorecard. Use the parameters to narrow down the runs to the particular case you are interested in.
## flame graphs
With the excellent [Flame Graph](https://github.com/brendangregg/FlameGraph) by Brendan Gregg, scorecard can turn the `dtrace` samples into an interactive SVG. Set the environment variable `FLAMEGRAPH` to the location of your clone of that project and invoked scorecard with the `--flame` option. Like
With the excellent [Flame Graph](https://github.com/brendangregg/FlameGraph) by Brendan Gregg, scorecard can turn `perf`/`dtrace` samples into an interactive SVG. Either clone the `Flamegraph` repository next to your `curl` project or set the environment variable `FLAMEGRAPH` to the location of your clone. Then run scorecard with the `--flame` option, like
```
curl> FLAMEGRAPH=/Users/sei/projects/FlameGraph python3 tests/http/scorecard.py \
@ -75,4 +69,13 @@ curl> FLAMEGRAPH=/Users/sei/projects/FlameGraph python3 tests/http/scorecard.py
```
and the SVG of the run is in `tests/http/gen/curl/curl.flamegraph.svg`. You can open that in Firefox and zoom in/out of stacks of interest.
Note: as with `dtrace`, the flame graph is for the last invocation of curl done by scorecard.
The flame graph is about the last run of `curl`. That is why you should add scorecard arguments
that restrict measurements to a single run.
### Measures/Privileges
The `--flame` option uses `perf` on linux and `dtrace` on macOS. Since both tools require special
privileges, they are run via the `sudo` command by scorecard. This means you need to issue a
`sudo` recently enough before running scorecard, so no new password check is needed.
There is no support right now for measurements on other platforms.