| # 2022-12-06 Triage Log |
| |
| A mixed bag of a week. 2 of the 3 regressions are connected to changes to the |
| query system that underlies incremental compilation. The third regression is |
| still being investigated. For all three, the impact on cycle counts that are |
| within our noise tolerance levels There were several small-ish improvements, |
| though PR #104963 is worth calling out: a well-factored change to |
| how we lower the AST into HIR that had a broad positive impact. One final |
| note: the summary-opt max-rss seems to gone up by 1.5% over the past month |
| ([perf](https://perf.rust-lang.org/?start=2022-11-06&end=2022-12-06&kind=percentfromfirst&stat=max-rss)), |
| via a gradual climb; just something to keep our eyes on going forward. |
| |
| |
| Triage done by **@pnkfelix**. |
| Revision range: [8a09420a..9db224fc](https://perf.rust-lang.org/?start=8a09420ac48658cad726e0a6997687ceac4151e3&end=9db224fc908059986c179fc6ec433944e9cfce50&absolute=false&stat=instructions%3Au) |
| |
| **Summary**: |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:-----:|:--------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | 0.6% | [0.2%, 1.5%] | 52 | |
| | Regressions ❌ <br /> (secondary) | 1.2% | [0.2%, 5.6%] | 80 | |
| | Improvements ✅ <br /> (primary) | -0.8% | [-1.7%, -0.2%] | 34 | |
| | Improvements ✅ <br /> (secondary) | -2.2% | [-4.8%, -0.2%] | 29 | |
| | All ❌✅ (primary) | 0.0% | [-1.7%, 1.5%] | 86 | |
| |
| |
| 3 Regressions, 7 Improvements, 4 Mixed; 3 of them in rollups |
| 50 artifact comparisons made in total |
| |
| #### Regressions |
| |
| Allow to feed a value in another query's cache [#104940](https://github.com/rust-lang/rust/pull/104940) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=90711a86e5bdd4b0b65d293f0c2c48fd2db761b3&end=c97b539e408ea353f4fde2f9251d598291fec421&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:----:|:------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | 0.3% | [0.2%, 0.4%] | 44 | |
| | Regressions ❌ <br /> (secondary) | 0.3% | [0.2%, 0.4%] | 12 | |
| | Improvements ✅ <br /> (primary) | - | - | 0 | |
| | Improvements ✅ <br /> (secondary) | - | - | 0 | |
| | All ❌✅ (primary) | 0.3% | [0.2%, 0.4%] | 44 | |
| |
| * Many primary benchmarks regressed, but the regression is contained solely to incremental builds, and the magnitude is also well-contained. |
| * [oli-obk investigated](https://github.com/rust-lang/rust/pull/104940#issuecomment-1333435955) and determined that |
| the bulk of the regression is time spent in try_mark_previous_green and incremental_verify_ich calls. |
| * The impact on cycle-counts (rather than instruction counts) was well within noise tolerance levels. |
| * Therefore, marked as triaged. |
| |
| Reduce macro usage for lints [#104863](https://github.com/rust-lang/rust/pull/104863) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=cef44f53034eac46be3a0e3eec7b2b3d4ef5140b&end=e960b5e7749e95c6a6b2fdec7250a48105664efb&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:----:|:------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | 0.5% | [0.2%, 1.4%] | 116 | |
| | Regressions ❌ <br /> (secondary) | 0.9% | [0.1%, 2.3%] | 83 | |
| | Improvements ✅ <br /> (primary) | - | - | 0 | |
| | Improvements ✅ <br /> (secondary) | - | - | 0 | |
| | All ❌✅ (primary) | 0.5% | [0.2%, 1.4%] | 116 | |
| |
| * [nnethercote is investigating](https://github.com/rust-lang/rust/pull/104863#issuecomment-1335853746) |
| * they have already put up [PR 105291](https://github.com/rust-lang/rust/pull/105291) which fixed a few cases but the bulk remain |
| * they have also [posted a separate idea](https://github.com/rust-lang/rust/pull/104863#issuecomment-1338224753), to avoid calling empty `check_*` methods. |
| * not marking as triaged yet |
| |
| feed resolver_for_lowering instead of storing it in a field [#105220](https://github.com/rust-lang/rust/pull/105220) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=226202d9026b0f24b4f7aad4de398bd8378774cd&end=ed61c139c2bc778ebb91f5dd6a5393aa20467f78&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:-----:|:--------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | 0.2% | [0.2%, 0.3%] | 2 | |
| | Regressions ❌ <br /> (secondary) | 0.5% | [0.1%, 0.8%] | 15 | |
| | Improvements ✅ <br /> (primary) | - | - | 0 | |
| | Improvements ✅ <br /> (secondary) | -0.3% | [-0.3%, -0.3%] | 1 | |
| | All ❌✅ (primary) | 0.2% | [0.2%, 0.3%] | 2 | |
| |
| |
| * the original timer run said [this had no problem](https://github.com/rust-lang/rust/pull/105220#issuecomment-1336312355) |
| * (though to be fair, I don't know what changes occurred to the commit series between that timer run and what landed) |
| * oli-obj investigated and found [cachegrind shows this to be artifacts from inlining decisions](https://github.com/rust-lang/rust/pull/105220#issuecomment-1338942653) |
| * The impact on cycle-counts (rather than instruction counts) was well within noise tolerance levels. |
| * Therefore, marked as triaged. |
| |
| #### Improvements |
| |
| Also cache the stable hash of interned Predicates [#94487](https://github.com/rust-lang/rust/pull/94487) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=e0098a5cc3a87d857e597af824d0ce1ed1ad85e0&end=bddad597feb997a4e5d2cd174a76c3b07a84e4d6&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:-----:|:--------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | - | - | 0 | |
| | Regressions ❌ <br /> (secondary) | - | - | 0 | |
| | Improvements ✅ <br /> (primary) | -0.4% | [-0.6%, -0.2%] | 12 | |
| | Improvements ✅ <br /> (secondary) | - | - | 0 | |
| | All ❌✅ (primary) | -0.4% | [-0.6%, -0.2%] | 12 | |
| |
| |
| Some initial normalization method changes [#104905](https://github.com/rust-lang/rust/pull/104905) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=a569a88f5500e8780c7cc65fa53fc8b098517674&end=24606deaf48e56f604a6125fa11fb9f70cf4f1f4&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:-----:|:--------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | - | - | 0 | |
| | Regressions ❌ <br /> (secondary) | - | - | 0 | |
| | Improvements ✅ <br /> (primary) | -0.9% | [-1.0%, -0.8%] | 2 | |
| | Improvements ✅ <br /> (secondary) | -2.2% | [-2.8%, -0.3%] | 7 | |
| | All ❌✅ (primary) | -0.9% | [-1.0%, -0.8%] | 2 | |
| |
| |
| Attribute cleanups [#104861](https://github.com/rust-lang/rust/pull/104861) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=744a97b98c3f2722e1a43486c05203b04e499e21&end=d6c4de0fb22fe8f3cc5a27e94b6b6d88fb504a91&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:-----:|:--------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | - | - | 0 | |
| | Regressions ❌ <br /> (secondary) | - | - | 0 | |
| | Improvements ✅ <br /> (primary) | -0.2% | [-0.2%, -0.1%] | 3 | |
| | Improvements ✅ <br /> (secondary) | -0.7% | [-0.9%, -0.5%] | 6 | |
| | All ❌✅ (primary) | -0.2% | [-0.2%, -0.1%] | 3 | |
| |
| |
| rustc_ast_lowering: Stop lowering imports into multiple items [#104963](https://github.com/rust-lang/rust/pull/104963) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=56c241c86212d84b9528dca1628bc06e32c742c1&end=11663b1b4857ffeafbd85a9a36c234d117373b76&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:-----:|:--------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | - | - | 0 | |
| | Regressions ❌ <br /> (secondary) | 0.6% | [0.6%, 0.6%] | 1 | |
| | Improvements ✅ <br /> (primary) | -0.5% | [-1.2%, -0.3%] | 54 | |
| | Improvements ✅ <br /> (secondary) | -4.2% | [-5.4%, -2.0%] | 13 | |
| | All ❌✅ (primary) | -0.5% | [-1.2%, -0.3%] | 54 | |
| |
| * Wow, I would not have expected this to have this significant of an impact. |
| * bravo petrochenkov |
| |
| Ensure query backtraces work for `DefId`s created after ast lowering [#105133](https://github.com/rust-lang/rust/pull/105133) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=24f2704e96c9d3a4f887d2d0a7d79ecffd79bd65&end=703d95e183fbb678249d8f61cabc732e46884e00&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:-----:|:--------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | - | - | 0 | |
| | Regressions ❌ <br /> (secondary) | - | - | 0 | |
| | Improvements ✅ <br /> (primary) | -0.2% | [-0.3%, -0.2%] | 5 | |
| | Improvements ✅ <br /> (secondary) | -0.2% | [-0.3%, -0.2%] | 2 | |
| | All ❌✅ (primary) | -0.2% | [-0.3%, -0.2%] | 5 | |
| |
| |
| Rewrite LLVM's archive writer in Rust [#97485](https://github.com/rust-lang/rust/pull/97485) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=4bb15759d7eb519be70c9a955dba9be09e13c06d&end=cab4fd678c5b148a330f2bf255bf28a67dfea0fc&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:-----:|:--------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | - | - | 0 | |
| | Regressions ❌ <br /> (secondary) | - | - | 0 | |
| | Improvements ✅ <br /> (primary) | -0.4% | [-0.6%, -0.2%] | 12 | |
| | Improvements ✅ <br /> (secondary) | - | - | 0 | |
| | All ❌✅ (primary) | -0.4% | [-0.6%, -0.2%] | 12 | |
| |
| |
| Cheaper `dump_mir` take two [#105121](https://github.com/rust-lang/rust/pull/105121) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=1195b672fb58364e4ca7022fbbe62a9a7a451b60&end=fd02567705326884ddb94535d2ab230a9595dc2a&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:-----:|:--------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | - | - | 0 | |
| | Regressions ❌ <br /> (secondary) | 0.9% | [0.9%, 0.9%] | 1 | |
| | Improvements ✅ <br /> (primary) | -1.1% | [-1.9%, -0.6%] | 17 | |
| | Improvements ✅ <br /> (secondary) | -1.4% | [-1.9%, -0.6%] | 9 | |
| | All ❌✅ (primary) | -1.1% | [-1.9%, -0.6%] | 17 | |
| |
| |
| #### Mixed |
| |
| Rollup of 9 pull requests [#105017](https://github.com/rust-lang/rust/pull/105017) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=8a09420ac48658cad726e0a6997687ceac4151e3&end=2585bcea0bc2a9c42a4be2c1eba5c61137f2b167&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:-----:|:--------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | 0.9% | [0.9%, 1.0%] | 2 | |
| | Regressions ❌ <br /> (secondary) | 3.7% | [2.2%, 5.6%] | 12 | |
| | Improvements ✅ <br /> (primary) | -0.6% | [-0.8%, -0.4%] | 7 | |
| | Improvements ✅ <br /> (secondary) | -1.1% | [-1.3%, -0.9%] | 4 | |
| | All ❌✅ (primary) | -0.3% | [-0.8%, 1.0%] | 9 | |
| |
| * nnethercote already [marked as triaged](https://github.com/rust-lang/rust/pull/105017#issuecomment-1333117104) |
| |
| Rollup of 14 pull requests [#105070](https://github.com/rust-lang/rust/pull/105070) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=bddad597feb997a4e5d2cd174a76c3b07a84e4d6&end=d38a99078cd3c4dadac1ba8b729ea77e8d1d5a82&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:-----:|:--------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | 0.6% | [0.4%, 0.9%] | 7 | |
| | Regressions ❌ <br /> (secondary) | 0.3% | [0.2%, 0.4%] | 7 | |
| | Improvements ✅ <br /> (primary) | -0.9% | [-1.0%, -0.8%] | 2 | |
| | Improvements ✅ <br /> (secondary) | -2.1% | [-2.7%, -1.4%] | 8 | |
| | All ❌✅ (primary) | 0.3% | [-1.0%, 0.9%] | 9 | |
| |
| * lqd [already investigated](https://github.com/rust-lang/rust/pull/105070#issuecomment-1332141661) |
| * all the primary regressions were deemed noise. |
| * marking as triaged. |
| |
| Rollup of 5 pull requests [#105080](https://github.com/rust-lang/rust/pull/105080) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=8de4b138455add55bde6de5553a933a2ab79b71f&end=a569a88f5500e8780c7cc65fa53fc8b098517674&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:-----:|:--------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | 0.9% | [0.8%, 1.0%] | 2 | |
| | Regressions ❌ <br /> (secondary) | 2.4% | [2.1%, 2.8%] | 6 | |
| | Improvements ✅ <br /> (primary) | -0.7% | [-0.9%, -0.5%] | 7 | |
| | Improvements ✅ <br /> (secondary) | - | - | 0 | |
| | All ❌✅ (primary) | -0.3% | [-0.9%, 1.0%] | 9 | |
| |
| |
| ° lqd already [marked as triaged](https://github.com/rust-lang/rust/pull/105080#issuecomment-1332124349) |
| |
| Disable top down MIR inlining [#105119](https://github.com/rust-lang/rust/pull/105119) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=8e440b03761f725d452120a992723c7e261822b2&end=226202d9026b0f24b4f7aad4de398bd8378774cd&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:-----:|:--------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | 0.4% | [0.2%, 1.0%] | 12 | |
| | Regressions ❌ <br /> (secondary) | 1.0% | [0.2%, 2.1%] | 15 | |
| | Improvements ✅ <br /> (primary) | -0.4% | [-1.0%, -0.2%] | 8 | |
| | Improvements ✅ <br /> (secondary) | -0.7% | [-1.0%, -0.1%] | 18 | |
| | All ❌✅ (primary) | 0.1% | [-1.0%, 1.0%] | 20 | |
| |
| |
| * nnethercote already [marked as triaged](https://github.com/rust-lang/rust/pull/105119#issuecomment-1338814158) |
| |
| #### Untriaged Pull Requests |
| |
| - [#105220 feed resolver_for_lowering instead of storing it in a field](https://github.com/rust-lang/rust/pull/105220) |
| - [#105070 Rollup of 14 pull requests](https://github.com/rust-lang/rust/pull/105070) |
| - [#104940 Allow to feed a value in another query's cache](https://github.com/rust-lang/rust/pull/104940) |
| - [#104863 Reduce macro usage for lints](https://github.com/rust-lang/rust/pull/104863) |
| - [#104566 couple of clippy::perf fixes](https://github.com/rust-lang/rust/pull/104566) |
| - [#104533 Clean up and harden various methods around trait substs](https://github.com/rust-lang/rust/pull/104533) |
| - [#104017 Rollup of 5 pull requests](https://github.com/rust-lang/rust/pull/104017) |
| - [#103998 Rollup of 6 pull requests](https://github.com/rust-lang/rust/pull/103998) |
| - [#103975 Some tracing and comment cleanups](https://github.com/rust-lang/rust/pull/103975) |
| - [#103934 std: sync "Dependencies of the `backtrace` crate" with `backtrace`](https://github.com/rust-lang/rust/pull/103934) |
| - [#103841 Rollup of 5 pull requests](https://github.com/rust-lang/rust/pull/103841) |
| - [#103650 rustdoc: change `.src-line-numbers > span` to `.src-line-numbers > a`](https://github.com/rust-lang/rust/pull/103650) |
| - [#103562 Rollup of 10 pull requests](https://github.com/rust-lang/rust/pull/103562) |
| - [#103439 Show note where the macro failed to match](https://github.com/rust-lang/rust/pull/103439) |
| - [#103295 ci: Bring back ninja for dist builders](https://github.com/rust-lang/rust/pull/103295) |
| - [#103071 Fix line numbers for MIR inlined code](https://github.com/rust-lang/rust/pull/103071) |
| - [#102975 Rollup of 7 pull requests](https://github.com/rust-lang/rust/pull/102975) |
| - [#102915 Rollup of 7 pull requests](https://github.com/rust-lang/rust/pull/102915) |
| - [#102895 Get rid of `rustc_query_description!`](https://github.com/rust-lang/rust/pull/102895) |
| - [#102867 Rollup of 6 pull requests](https://github.com/rust-lang/rust/pull/102867) |
| - [#102809 Rollup of 8 pull requests](https://github.com/rust-lang/rust/pull/102809) |
| - [#102570 Perform simple scalar replacement of aggregates (SROA) MIR opt](https://github.com/rust-lang/rust/pull/102570) |
| - [#102548 Mark Cell::replace() as #[inline]](https://github.com/rust-lang/rust/pull/102548) |
| - [#102026 Populate effective visibilities in 'rustc_resolve'](https://github.com/rust-lang/rust/pull/102026) |
| - [#101858 derive various impls instead of hand-rolling them](https://github.com/rust-lang/rust/pull/101858) |
| - [#101857 change `FnMutDelegate` to trait objects](https://github.com/rust-lang/rust/pull/101857) |
| - [#101702 rustdoc: add hash to filename of toolchain files](https://github.com/rust-lang/rust/pull/101702) |
| - [#101632 Remove `TypeckResults` from `InferCtxt`](https://github.com/rust-lang/rust/pull/101632) |
| - [#101620 Compute lint levels by definition](https://github.com/rust-lang/rust/pull/101620) |
| - [#101433 Emit a note that static bounds from HRTBs are a bug](https://github.com/rust-lang/rust/pull/101433) |
