| # 2024-03-05 Triage Log |
| |
| A bunch of noise this week which has been dropped from the report (but may be |
| present in the summary figures). As a result, the week is pretty busy in amount |
| of changes, but the net effect is nearly neutral to a slight regression for |
| most workloads. |
| |
| Triage done by **@simulacrum**. |
| Revision range: [71ffdf7ff7ac6df5f9f64de7e780b8345797e8a0..41d97c8a5dea2731b0e56fe97cd7cb79e21cff79](https://perf.rust-lang.org/?start=71ffdf7ff7ac6df5f9f64de7e780b8345797e8a0&end=41d97c8a5dea2731b0e56fe97cd7cb79e21cff79&absolute=false&stat=instructions%3Au) |
| |
| **Summary**: |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:-----:|:--------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | 0.6% | [0.1%, 2.0%] | 136 | |
| | Regressions ❌ <br /> (secondary) | 0.8% | [0.2%, 2.6%] | 78 | |
| | Improvements ✅ <br /> (primary) | -0.6% | [-1.2%, -0.3%] | 9 | |
| | Improvements ✅ <br /> (secondary) | -0.6% | [-1.0%, -0.2%] | 14 | |
| | All ❌✅ (primary) | 0.6% | [-1.2%, 2.0%] | 145 | |
| |
| |
| 2 Regressions, 0 Improvements, 10 Mixed; 4 of them in rollups |
| 51 artifact comparisons made in total |
| |
| #### Regressions |
| |
| Weekly `cargo update` [#112865](https://github.com/rust-lang/rust/pull/112865) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=0decdac390cfeedcd7f2f44c45f72c59c70d8143&end=da02fff3b6e4e27156054dcdda6675fe2a2591a6&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:----:|:------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | 1.1% | [0.2%, 2.9%] | 3 | |
| | Regressions ❌ <br /> (secondary) | 1.1% | [0.2%, 1.9%] | 7 | |
| | Improvements ✅ <br /> (primary) | - | - | 0 | |
| | Improvements ✅ <br /> (secondary) | - | - | 0 | |
| | All ❌✅ (primary) | 1.1% | [0.2%, 2.9%] | 3 | |
| |
| Doesn't appear to be entirely noise (though some of the delta is likely due to |
| bimodality). However marking this regression as triaged since investigating is |
| likely to be painful and the regressions are predominantly in secondary |
| benchmarks. |
| |
| Add a scheme for moving away from `extern "rust-intrinsic"` entirely [#120675](https://github.com/rust-lang/rust/pull/120675) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=50e77f133f8eb1f745e05681163a0143d6c4dd7d&end=2eeff462b762ed00f9d557d8c6ad7a3d562f692a&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:----:|:------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | 0.6% | [0.2%, 1.0%] | 93 | |
| | Regressions ❌ <br /> (secondary) | 0.8% | [0.2%, 2.4%] | 28 | |
| | Improvements ✅ <br /> (primary) | - | - | 0 | |
| | Improvements ✅ <br /> (secondary) | - | - | 0 | |
| | All ❌✅ (primary) | 0.6% | [0.2%, 1.0%] | 93 | |
| |
| This regression is being addressed in a followup PR: |
| https://github.com/rust-lang/rust/pull/122010 |
| |
| #### Mixed |
| |
| syms for legacy numeric constants diag items [#121667](https://github.com/rust-lang/rust/pull/121667) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=91cae1dcdcf1a31bd8a92e4a63793d65cfe289bb&end=1c28a2c1b0b82b525262e6ccc7675cab61ed040c&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:-----:|:--------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | - | - | 0 | |
| | Regressions ❌ <br /> (secondary) | 0.5% | [0.3%, 1.1%] | 3 | |
| | Improvements ✅ <br /> (primary) | -0.3% | [-0.3%, -0.2%] | 2 | |
| | Improvements ✅ <br /> (secondary) | -0.8% | [-1.5%, -0.2%] | 3 | |
| | All ❌✅ (primary) | -0.3% | [-0.3%, -0.2%] | 2 | |
| |
| Regression seems likely to be noise (bimodality) or not significant enough to |
| investigate further. Marking as triaged. Some of the improvements seem genuine. |
| |
| Diagnostic renaming [#121489](https://github.com/rust-lang/rust/pull/121489) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=bf9c7a64ad222b85397573668b39e6d1ab9f4a72&end=c475e2303b551d726307c646181e0677af1e0069&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:-----:|:--------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | - | - | 0 | |
| | Regressions ❌ <br /> (secondary) | 1.2% | [1.2%, 1.2%] | 1 | |
| | Improvements ✅ <br /> (primary) | -0.9% | [-0.9%, -0.8%] | 4 | |
| | Improvements ✅ <br /> (secondary) | -0.5% | [-0.8%, -0.4%] | 9 | |
| | All ❌✅ (primary) | -0.9% | [-0.9%, -0.8%] | 4 | |
| |
| Regression is essentially guaranteed to be bimodality, not a real change. Marking as triaged. |
| |
| Rollup of 10 pull requests [#121790](https://github.com/rust-lang/rust/pull/121790) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=d3d145ea1cae47ad392173f890577788117da3d9&end=71a7b66f20c551f640f2f382bc7e7923ba0a5dab&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:-----:|:--------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | 0.6% | [0.6%, 0.6%] | 1 | |
| | Regressions ❌ <br /> (secondary) | - | - | 0 | |
| | Improvements ✅ <br /> (primary) | -0.4% | [-0.6%, -0.3%] | 2 | |
| | Improvements ✅ <br /> (secondary) | -1.9% | [-2.4%, -1.5%] | 2 | |
| | All ❌✅ (primary) | -0.1% | [-0.6%, 0.6%] | 3 | |
| |
| The single primary benchmark regression (Cargo) change looks to be both above |
| any noise floor and does not show signs of reverting. However, it's not |
| significant enough (given limit to just Cargo) to investigate further. |
| |
| Rollup of 7 pull requests [#121804](https://github.com/rust-lang/rust/pull/121804) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=384d26fc7e3bdd7687cc17b2662b091f6017ec2a&end=1a1876c9790f168fb51afa335a7ba3e6fc267d75&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:-----:|:--------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | 0.3% | [0.2%, 0.6%] | 7 | |
| | Regressions ❌ <br /> (secondary) | 1.8% | [1.7%, 1.9%] | 6 | |
| | Improvements ✅ <br /> (primary) | -0.8% | [-0.9%, -0.8%] | 4 | |
| | Improvements ✅ <br /> (secondary) | -0.5% | [-0.8%, -0.2%] | 8 | |
| | All ❌✅ (primary) | -0.1% | [-0.9%, 0.6%] | 11 | |
| |
| Trying to track down the cause of the regression. Suspecting #121000 based on |
| the regressed benchmarks. |
| |
| Combine `Sub` and `Equate` [#121462](https://github.com/rust-lang/rust/pull/121462) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=6cbf0926d54c80ea6d15df333be9281f65bbeb36&end=b0696a5160711c068cb1f01b7437db7990d15750&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:-----:|:--------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | 0.5% | [0.2%, 0.9%] | 13 | |
| | Regressions ❌ <br /> (secondary) | 0.5% | [0.3%, 0.8%] | 17 | |
| | Improvements ✅ <br /> (primary) | - | - | 0 | |
| | Improvements ✅ <br /> (secondary) | -0.5% | [-0.9%, -0.4%] | 7 | |
| | All ❌✅ (primary) | 0.5% | [0.2%, 0.9%] | 13 | |
| |
| Future PRs may improve perf here, but this is targeting clean up and preparing for other refactoring first: |
| |
| > Some ideas how to reduce the perf impact. Even if they don't completely |
| > remove it, this will allow significant improvements and cleanups going |
| > forward and generally simplifies the core type system. I would merge this |
| > even with these regressions. |
| |
| (https://github.com/rust-lang/rust/pull/121462#issuecomment-1973282815) |
| |
| Rollup of 12 pull requests [#121859](https://github.com/rust-lang/rust/pull/121859) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=17edacef07e8afc3b580ed8feead6c5e90d24a56&end=2dceda4f32b97f60b122f2b32491e0267ef5cc0c&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:-----:|:--------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | 1.9% | [0.5%, 3.3%] | 2 | |
| | Regressions ❌ <br /> (secondary) | - | - | 0 | |
| | Improvements ✅ <br /> (primary) | -0.8% | [-1.1%, -0.5%] | 2 | |
| | Improvements ✅ <br /> (secondary) | - | - | 0 | |
| | All ❌✅ (primary) | 0.6% | [-1.1%, 3.3%] | 4 | |
| |
| Cargo regression looks real but otherwise this looks like noise to me. I'm |
| going to mark as triaged, I don't think it merits digging through individual |
| PRs to try and isolate it. |
| |
| Don't grab variances in `TypeRelating` relation if we're invariant [#121864](https://github.com/rust-lang/rust/pull/121864) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=4cdd20584ccb75890d7d9bfae266054abfae5d46&end=2e3581bca93fdcce474e17cd43430b594a7955a0&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:-----:|:--------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | - | - | 0 | |
| | Regressions ❌ <br /> (secondary) | 0.2% | [0.2%, 0.2%] | 1 | |
| | Improvements ✅ <br /> (primary) | -0.6% | [-0.8%, -0.2%] | 11 | |
| | Improvements ✅ <br /> (secondary) | -0.5% | [-0.6%, -0.4%] | 8 | |
| | All ❌✅ (primary) | -0.6% | [-0.8%, -0.2%] | 11 | |
| |
| Regression is likely real, but is in a secondary benchmark and incr-unchanged |
| scenario. Not worth further investigation, particularly given the improvements. |
| |
| Always generate GEP i8 / ptradd for struct offsets [#121665](https://github.com/rust-lang/rust/pull/121665) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=516b6162a2ea8e66678c09e8243ebd83e4b8eeea&end=70aa0b86c066e721012852a9851fdf8586117823&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:-----:|:--------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | 0.3% | [0.2%, 0.4%] | 3 | |
| | Regressions ❌ <br /> (secondary) | 0.5% | [0.2%, 1.0%] | 12 | |
| | Improvements ✅ <br /> (primary) | -0.7% | [-1.6%, -0.3%] | 14 | |
| | Improvements ✅ <br /> (secondary) | -0.5% | [-1.0%, -0.3%] | 12 | |
| | All ❌✅ (primary) | -0.5% | [-1.6%, 0.4%] | 17 | |
| |
| Changes are expected since this changed a lot of our codegen. In practice |
| though mostly not meaningful (i.e., some improvements, some regressions). |
| |
| Rollup of 5 pull requests [#121955](https://github.com/rust-lang/rust/pull/121955) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=70aa0b86c066e721012852a9851fdf8586117823&end=89b78304e82dc5114e3b2faa0fbec747a28a2b37&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:-----:|:--------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | 0.7% | [0.2%, 3.7%] | 17 | |
| | Regressions ❌ <br /> (secondary) | - | - | 0 | |
| | Improvements ✅ <br /> (primary) | -0.4% | [-0.8%, -0.2%] | 10 | |
| | Improvements ✅ <br /> (secondary) | - | - | 0 | |
| | All ❌✅ (primary) | 0.3% | [-0.8%, 3.7%] | 27 | |
| |
| Likely to be caused by a correctness fix: https://github.com/rust-lang/rust/pull/121955#issuecomment-1975993842 |
| |
| perf: improve write_fmt to handle simple strings [#121001](https://github.com/rust-lang/rust/pull/121001) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=1547c076bfec8abb819d6a81e1e4095d267bd5b4&end=5a1e5449c8f4cb6b12b4f64238e3c058767ebf02&stat=instructions:u) |
| |
| | (instructions:u) | mean | range | count | |
| |:----------------------------------:|:-----:|:--------------:|:-----:| |
| | Regressions ❌ <br /> (primary) | 1.7% | [0.5%, 3.6%] | 4 | |
| | Regressions ❌ <br /> (secondary) | 0.3% | [0.3%, 0.3%] | 1 | |
| | Improvements ✅ <br /> (primary) | - | - | 0 | |
| | Improvements ✅ <br /> (secondary) | -1.3% | [-1.3%, -1.3%] | 1 | |
| | All ❌✅ (primary) | 1.7% | [0.5%, 3.6%] | 4 | |
| |
| Improvements to runtime (or at least assembly quality), at the cost of a bit |
| more time in LLVM. |