eslint-plugin-import
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import-js
no-cycle performance in 2.30 is even worse than 2.27.5
Hey, Is there any benchmark for the new SCC algorithm?
In a project I am maintaining, 2x more time is used compared with 2.27.5. it has 544 files project(in monorepo).
| Version | 2.27.5 | 2.30.0 |
|---|---|---|
| Time | ~40s | ~80s |
2.30.0
Rule | Time (ms) | Relative
:-----------------------------------------------|----------:|--------:
import/no-cycle | 58328.676 | 79.2%
2.27.5
Rule | Time (ms) | Relative
:-----------------------------------------------|----------:|--------:
import/no-cycle | 15741.654 | 45.8%
It depends on the size of the codebase and a number of other factors - try setting the disableScc option to true?
@ljharb
if set disableScc as true, we are back to 2.27.5. the time is around 40s 😅
this project has around 500 files and 156k lines of code.
Rule | Time (ms) | Relative
:-----------------------------------------------|----------:|--------:
import/no-cycle | 5751.410 | 20.6%
===============================================================================
Language Files Lines Code Comments Blanks
===============================================================================
JavaScript 5 86 69 6 11
TypeScript 550 169737 156696 6472 6569
===============================================================================
Total 555 169823 156765 6478 6580
===============================================================================
btw, in another project that has more than 7800 files. a 16 cores 32 GB memory server cannot finish in 1 hour, and the node(lint) process took almost 8G memory
I had a project where SCC clearly made a significant good impact:
https://github.com/import-js/eslint-plugin-import/pull/2998#issuecomment-2310643941
With 7k files, and almost 400kloc,
So what is it about your project's configuration that makes it so slow and resource-intensive?
I posted a result when setting disableScc to true, so I think it's clear that SCC made the performance issue.
And this comment might be the reason: https://github.com/un-ts/eslint-plugin-import-x/issues/113#issuecomment-2328289185
Our project is pretty huge, with over 2 million lines of code... it's quite hard to put it here.
eslint version is 8.39.0
The linked comment is in eslint-plugin-import-x which is a community fork. If you want them to make a change to their library, please bring it up on their repository.
I doubt that the impact of their proposed replacing of @rtsao/scc with @newdash/graphlib will make much of a difference on performance. Running Tarjan-SCC pre-processing, whether with that library or with another library, will add some work to do so require a performance hit for small projects.
As for your 2mloc project, is that the same that has only 7800 files?
Are you sure the issue is with the choice of SCC library, as opposed to some other step like parsing or ExportMap construction?
Would love to see a profiler output (e.g. flamegraph). How much time are we spending in Tarjan-SCC and how much in other steps?
It depends on the size of the codebase and a number of other factors - try setting the disableScc option to true?
Created an issue to add disableScc to the docs:
- https://github.com/import-js/eslint-plugin-import/issues/3063
our project is a mono repo, including many projects. the whole repo is over 2mloc. and one of the largest one is over 7800 files. I'm using a smaller project to test(544 files, the profiling file generated from this project)
here is the profiling file. and using https://www.speedscope.app/ (please let me know once you downloaded, I'll delete it): isolate-0x51a8150-1444136-v8.log.json
Why are we spending so much time in SCC? It's a linear algorithm. Are we running it many times?
You said mono repo, so I suspect maybe it has something to do with the way ExportMap handles externals?
The projects I tested on didn't have many, so maybe there's a pathology when a monorepo has many eslint/ts configs?
@AnnatarHe Please try version 2.31.0, it includes the fix from https://github.com/import-js/eslint-plugin-import/pull/3068.
Is performance better with/without disableScc?
@soryy708 no significant difference. so it looks like the new version brings the performance back to previous version
disableScc: true
Rule | Time (ms) | Relative
:-----------------------------------------------|-----------:|--------:
import/no-cycle | 110489.719 | 90.2%
prettier/prettier | 9351.288 | 7.6%
import/namespace | 834.045 | 0.7%
unused-imports/no-unused-imports | 531.654 | 0.4%
Executed in 137.36 secs fish external
usr time 163.09 secs 306.00 micros 163.09 secs
sys time 11.42 secs 173.00 micros 11.42 secs
disableScc: false
Rule | Time (ms) | Relative
:-----------------------------------------------|-----------:|--------:
import/no-cycle | 116099.013 | 90.8%
prettier/prettier | 8842.955 | 6.9%
import/namespace | 924.044 | 0.7%
unused-imports/no-unused-imports | 561.242 | 0.4%
Executed in 143.02 secs fish external
usr time 171.97 secs 327.00 micros 171.97 secs
sys time 11.48 secs 184.00 micros 11.48 secs
@AnnatarHe pardon I think I don't follow, which one of the multiple projects mentioned was this recent benchmark in?
Also if we're talking specifically about no-cycle, lets isolate the variables to just that, by disabling all other lint rules, so that we get more repeatable results.
When you say
the new version brings the performance back to previous version
which version do you mean? did performance return to the same as you had in 2.27.5?
