Tier of Support: Linux perf and V8 --interpreted-frames-native-stack current state

[Drieger]

I tried to summarize current state of requisites for Linux perf. Requisites are taken from Tier 1 (most complete set of requirements).

There are some requirements that seem to be subjective (at least to me), which means it's not clear if a tool fulfills it or not.

Requisites

• Must always be working (CI tests passing) for all LTS Node.js
• Have a good test suite
• Test suite job must exist in Node.js CI
• The maintainers of the tool must remain responsive when there are problems (Subjective)
• The tool must be actively used by the ecosystem (Subjective)
• The tool must be heavily depended on (Subjective)
• The tool must have a guide or other documentation in the Node.js GitHub organization or website
• The tool must be working on all supported platforms
• The tool must only be using APIs exposed by Nodejs as opposed to its dependencies
• The tool must be open source.

Tool Analysis

Name	Linux perf
URL	https://github.com/torvalds/linux/tree/master/tools/perf
Type	Profiling
Current Tier	3 (according to guide)
Target Tier	2

Requisite	Status	Observation
Must always be working (CI tests passing) for all LTS Node.js	Maybe	It isn't related specific to Node.js versions. And --perf-basic-prof is working correctly
Have a good test suite	Ok	Tool has a good test suite
Test suite job must exist in Node.js CI	Ok	Test might be found on test/v8-updates/test-linux-perf.js
The maintainers of the tool must remain responsive when there are problems	Ok	As this tool is under Linux development community, maintainers should be fairly responsive. Also --perf-basic-prof is under V8 supervision
The tool must be actively used by the ecosystem	Maybe	Hard to tell as this is an analysis tool that comes with many Linux distributions
The tool must be heavily depended on	Fail	Diagnostic/analysis tools are almost never depended on to run systems.
The tool must have a guide or other documentation in the Node.js GitHub organization or website	Fail	Tool doesn't have any guide in the Node.js Github organization or website. Tool has a good documentaion https://github.com/torvalds/linux/tree/master/tools/perf/Documentation --perf-basic-prof has almost no documentation in organization Github or website
The tool must be working on all supported platforms	Fail	Tool only works on Linux based platforms
The tool must only be using APIs exposed by Nodejs as opposed to its dependencies	Ok	Tools has no dependencies from Node.js. Only dependency we might consider here is to use the `--perf-basic-prof` or related flags
The tool must be open source	Ok	Tool is open source, under the GNU GPL. --perf-basic-prof is under V8 and is open source as well

Based on this it is possible to have a more clear view of the current state and what is necessary to work on to move Linux perf to target tier. It is also an opportunity to debate if requirements are correct. Any ideas and opinions are welcome.

[mcollina]

I think we should move The tool must be working on all supported platforms to the "if-applicable" category, and relax this for Linux perf.

Diagnostic/analysis tools are almost never depended on to run systems.

This will be true for all tools that are tracked via this process. IMHO perf is lightly depended on, as several companies are depending on this to work, e.g. Netflix. We used it quite ofter at NearForm as well.

Must always be working (CI tests passing) for all LTS Node.js

I think perf integration is broken on Node 8, and it's not really fixable. @mmarchini added a flag to fix the data in Node 10+.

[naugtur]

As for the docs/guide

I've been working on a guide for flame graphs using perf and it's been almost finished for a while, but I couldn't get it to display correct function names (yes, with the new flags) because of OS support issues. I wanted to figure those out before finally posting.
I'm hoping to finish it soon

nodejs/nodejs.org#1444

[Drieger]

Great @naugtur 😄
As soon as it is merged we can update the state here.

[Drieger]

As pointed by @mcollina in #262, it makes more sense to evaluate perf and --interpreted-frames-native-stack together, so I will move --interpreted-frames-native-stack current state to continue its evaluation here.

Tool Analysis

Name	V8 --interpreted-frames-native-stack
Type	Profiling
Current Tier	3 (according to guide)
Target Tier	2

Requisite	Status	Observation
Must always be working (CI tests passing) for all LTS Node.js	Maybe	Flag was added on Node.js v10.x. So since that version, all LTS Node.js should be ok
Have a good test suite	Maybe	Test exists for the feature. I'm not sure if test coverage enough
Test suite job must exist in Node.js CI	Maybe	Tests are run based on V8 (test/v8-updates/test-linux-perf.js)
The maintainers of the tool must remain responsive when there are problems	Ok	This is mantained as part of V8, so should be ok
The tool must be actively used by the ecosystem	Maybe	No metrics available to define this
The tool must be heavily depended on	Maybe	It is hard to define it, specially if we think that the ecosystem could be only people interested in diagnostics/profiling/...
The tool must have a guide or other documentation in the Node.js GitHub organization or website	Fail	Tool doesn't have any guide in the Node.js Github organization or website.README file in its own repository with a some usage explanation
The tool must be working on all supported platforms	True	Works on all platforms where V8 is also working
The tool must only be using APIs exposed by Nodejs as opposed to its dependencies	Fail	Tool must use some of its dependencies. But it is necessary for this kind of tool
The tool must be open source	Ok	Tool is part of V8

[github-actions]

This issue is stale because it has been open many days with no activity. It will be closed soon unless the stale label is removed or a comment is made.

[github-actions]

This issue is stale because it has been open many days with no activity. It will be closed soon unless the stale label is removed or a comment is made.