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Add more profiling traces #14238

Merged
merged 1 commit into from
Jul 11, 2024
Merged

Add more profiling traces #14238

merged 1 commit into from
Jul 11, 2024

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epage
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@epage epage commented Jul 11, 2024

What does this PR try to resolve?

Someone suggested I look at
zed.
It has some interesting performance characteristics compared to projects I looked at before:

  • A lot of workspace members
  • git dependencies
  • patching with git dependencies

This adds traces that help provide more context for those scenarios when looking at them.

image

How should we test and review this PR?

Additional information

Some of these areas might be of interest for
optimizing:

Someone suggested I look at
[zed](https://github.com/zed-industries/zed).
It has some interesting performance characteristics compared to projects
I looked at before:
- A lot of workspace members
- git dependencies
- patches

This adds traces that help provide more context for those scenarios when
looking at them.

Some of these areas might be of interest for
optimizing:
- On every invocation, we do a git2 `copy_to` call for each git checkout
- On every invocation, we do a `du` on each git checkout
- It'd be great to avoid parsing every manifest in a git checkout but we
  need to do a full parse to make sure we find all packages (see
  https://rust-lang.zulipchat.com/#narrow/stream/246057-t-cargo/topic/Redundant.20code.20in.20.60GitSouce.60.3F)
- Its suspicious how much time we spend in the "poison" step of
  resolving when its a no-op
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rustbot commented Jul 11, 2024

r? @ehuss

rustbot has assigned @ehuss.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

@rustbot rustbot added A-git Area: anything dealing with git A-registries Area: registries A-workspaces Area: workspaces Command-read-manifest S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Jul 11, 2024
src/cargo/ops/resolve.rs Outdated Show resolved Hide resolved
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arlosi commented Jul 11, 2024

Thanks

@bors r+

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bors commented Jul 11, 2024

📌 Commit 89eb406 has been approved by arlosi

It is now in the queue for this repository.

@bors bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Jul 11, 2024
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bors commented Jul 11, 2024

⌛ Testing commit 89eb406 with merge 8519ad2...

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bors commented Jul 11, 2024

☀️ Test successful - checks-actions
Approved by: arlosi
Pushing 8519ad2 to master...

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bors commented Jul 11, 2024

☀️ Test successful - checks-actions
Approved by: arlosi
Pushing 8519ad2 to master...

@bors bors merged commit 8519ad2 into rust-lang:master Jul 11, 2024
22 checks passed
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bors commented Jul 11, 2024

👀 Test was successful, but fast-forwarding failed: 422 Changes must be made through a pull request.

@epage epage deleted the traces branch July 12, 2024 00:58
epage added a commit to epage/cargo that referenced this pull request Jul 15, 2024
When profiling Zed (rust-lang#14238), a major factor in their no-op run times
is git patches and git dependencies.  The slowest operation for each git
source is running `du`.  This is extraneous for a couple of reasons
- GC isn't stable, slowing people down for a feature they aren't using
- Size tracking was expected to be lazy, only reading sizes when the GC
  is configured for size, while this was eager
- Git checkouts are immutable but we check on every load
- This optimized for "while filesystem caches are warm" from a checkout
  operation when checkout operations are rare compared to all of the other
  commands run on a working directory.

This removes the `du`, relying on the lazy loading that happens in
`update_null_sizes`.
bors added a commit that referenced this pull request Jul 15, 2024
perf(source): Don't `du` on every git source load

### What does this PR try to resolve?

When profiling Zed (#14238), a major factor in their no-op run times is git patches and git dependencies.  The slowest operation for each git source is running `du`.  This is extraneous for a couple of reasons
- GC isn't stable, slowing people down for a feature they aren't using
- Size tracking was expected to be lazy, only reading sizes when the GC is configured for size, while this was eager
- Git checkouts are immutable but we check on every load
- This optimized for "while filesystem caches are warm" from a checkout operation when checkout operations are rare compared to all of the other commands run on a working directory.

This removes the `du`, relying on the lazy loading that happens in `update_null_sizes`.

For Zed, this removed about 40ms total from the runtime.  While by itself, this is below the threshold of being noticed,
- It adds up if any editor integrations are calling `cargo metadata` a lot
- Over time, small gains like this will add up

### How should we test and review this PR?

### Additional information

cc `@ehuss`
bors added a commit to rust-lang-ci/rust that referenced this pull request Jul 17, 2024
Update cargo

31 commits in 154fdac39ae9629954e19e9986fd2cf2cdd8d964..a2b58c3dad4d554ba01ed6c45c41ff85390560f2
2024-07-07 01:28:23 +0000 to 2024-07-16 00:52:02 +0000
- chore(ci): bump CI tools (rust-lang/cargo#14257)
- test: migrate fetch and list_availables to snapbox (rust-lang/cargo#14214)
- chore: downgrade to [email protected] (rust-lang/cargo#14254)
- perf(source): Don't `du` on every git source load (rust-lang/cargo#14252)
- fix(source): Don't warn about unreferenced duplicate packages (rust-lang/cargo#14239)
- feat(test): Add cargo_test to test-support prelude (rust-lang/cargo#14243)
- Add workflow to publish Cargo automatically (rust-lang/cargo#14202)
- test: migrate implicit_features to snapbox (rust-lang/cargo#14245)
- test: migrate build-std/main to snapbox (rust-lang/cargo#14241)
- test: migrate check_cfg to snapbox (rust-lang/cargo#14235)
- refactor(source): More RecursivePathSource clean up (rust-lang/cargo#14231)
- Add more profiling traces (rust-lang/cargo#14238)
- fix(overrides): Don't warn on duplicate packages from using '..' (rust-lang/cargo#14234)
- fix(test): Redact elapsed time in the minutes time frame (rust-lang/cargo#14233)
- test: Migrate lto tests to snapbox (rust-lang/cargo#14209)
- fix: Ensure dep/feature activates the dependency on 2024 (rust-lang/cargo#14221)
- chore(docs): update index of reference (rust-lang/cargo#14228)
- test: migrate test to snapbox (rust-lang/cargo#14226)
- chore: remove duplicate words (rust-lang/cargo#14229)
- docs(contrib): Document things I look for in RFCs (rust-lang/cargo#14222)
- docs(ref): Note MSRV for features in the docs (rust-lang/cargo#14224)
- test(progress): Resolve flakiness (rust-lang/cargo#14223)
- fix(test): Reduce over-prescription to the caller (rust-lang/cargo#14217)
- refactor: move get_source_id out of registry (rust-lang/cargo#14218)
- fix: rename to `rustdoc::broken_intra_doc_links` (rust-lang/cargo#14215)
- test: migrate member_errors, multitarget and new to snapbox (rust-lang/cargo#14210)
- test: migrate generate_lockfile and glob_targets to snapbox (rust-lang/cargo#14200)
- test: Ensure --list test works with cargo-bloat (rust-lang/cargo#14213)
- dont make new constant InternedString in hot path (rust-lang/cargo#14211)
- Fix compatible_with_older_cargo test. (rust-lang/cargo#14212)
- test: migrate metabuild, metadata and net_config to snapbox (rust-lang/cargo#14162)
@rustbot rustbot added this to the 1.81.0 milestone Jul 17, 2024
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5 participants