|
| 1 | +# 2022-09-27 Triage Log |
| 2 | + |
| 3 | +Overall a fairly quiet week in terms of new changes; the majority of the delta |
| 4 | +this week was due to reverting |
| 5 | +[#101620](https://github.com/rust-lang/rust/pull/101620), which was a |
| 6 | +regression noted in last week's report. |
| 7 | + |
| 8 | +Triage done by **@simulacrum**. |
| 9 | +Revision range: [8fd6d03e22fba2930ad377b87299de6a37076074..d9297d22ad9edc2b56f0dd8734c1187a0c88be69](https://perf.rust-lang.org/?start=8fd6d03e22fba2930ad377b87299de6a37076074&end=d9297d22ad9edc2b56f0dd8734c1187a0c88be69&absolute=false&stat=instructions%3Au) |
| 10 | + |
| 11 | +**Summary**: |
| 12 | + |
| 13 | +| (instructions:u) | mean | range | count | |
| 14 | +|:----------------:|:----:|:-----:|:-----:| |
| 15 | +| Regressions ❌ <br /> (primary) | 5.6% | [0.4%, 32.9%] | 32 | |
| 16 | +| Regressions ❌ <br /> (secondary) | 7.4% | [0.7%, 25.3%] | 22 | |
| 17 | +| Improvements ✅ <br /> (primary) | -4.0% | [-13.4%, -0.3%] | 135 | |
| 18 | +| Improvements ✅ <br /> (secondary) | -4.3% | [-19.4%, -0.1%] | 123 | |
| 19 | +| All ❌✅ (primary) | -2.2% | [-13.4%, 32.9%] | 167 | |
| 20 | + |
| 21 | + |
| 22 | +2 Regressions, 7 Improvements, 3 Mixed; 3 of them in rollups |
| 23 | +53 artifact comparisons made in total |
| 24 | + |
| 25 | +#### Regressions |
| 26 | + |
| 27 | +a fn pointer doesn't implement `Fn`/`FnMut`/`FnOnce` if its return type isn't sized [#100096](https://github.com/rust-lang/rust/pull/100096) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=4ecfdfac51b159f68fce608792affb34a70e6f73&end=1de00d1ac5247a02184ef7ad044f6521ade7e0cc&stat=instructions:u) |
| 28 | + |
| 29 | +| (instructions:u) | mean | range | count | |
| 30 | +|:----------------:|:----:|:-----:|:-----:| |
| 31 | +| Regressions ❌ <br /> (primary) | - | - | 0 | |
| 32 | +| Regressions ❌ <br /> (secondary) | 23.0% | [21.3%, 25.2%] | 6 | |
| 33 | +| Improvements ✅ <br /> (primary) | - | - | 0 | |
| 34 | +| Improvements ✅ <br /> (secondary) | - | - | 0 | |
| 35 | +| All ❌✅ (primary) | - | - | 0 | |
| 36 | + |
| 37 | +Perf regression is being investigated by @compiler-errors. No positive fix yet |
| 38 | +though; due to the reported regression |
| 39 | +([#102289](https://github.com/rust-lang/rust/pull/102289)) we are thinking that |
| 40 | +just reverting may be the better option. This is a soundness fix though so the |
| 41 | +perf regression may be OK, but further investigation is warranted. |
| 42 | + |
| 43 | + |
| 44 | +Require `#[const_trait]` on `Trait` for `impl const Trait` [#100982](https://github.com/rust-lang/rust/pull/100982) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=626b02a8f97a9e35a647aa18fcdb67cbcb3b09c8&end=7a8636c843bd24038fe1d1f69b4a8e4b0ea55d4e&stat=instructions:u) |
| 45 | + |
| 46 | +| (instructions:u) | mean | range | count | |
| 47 | +|:----------------:|:----:|:-----:|:-----:| |
| 48 | +| Regressions ❌ <br /> (primary) | 0.4% | [0.4%, 0.5%] | 6 | |
| 49 | +| Regressions ❌ <br /> (secondary) | 1.5% | [1.5%, 1.5%] | 1 | |
| 50 | +| Improvements ✅ <br /> (primary) | - | - | 0 | |
| 51 | +| Improvements ✅ <br /> (secondary) | - | - | 0 | |
| 52 | +| All ❌✅ (primary) | 0.4% | [0.4%, 0.5%] | 6 | |
| 53 | + |
| 54 | +This regression was known prior to merging the PR, but the reviewer concluded |
| 55 | +that the small wall-clock delta wasn't worth further investigation. Left a |
| 56 | +comment asking for a better justification of the regression. |
| 57 | + |
| 58 | +#### Improvements |
| 59 | + |
| 60 | +use partition_point instead of binary_search when looking up source lines [#101999](https://github.com/rust-lang/rust/pull/101999) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=7a8636c843bd24038fe1d1f69b4a8e4b0ea55d4e&end=3e50038a2d4029bd1484af75dbf144c4b0da6c74&stat=instructions:u) |
| 61 | + |
| 62 | +| (instructions:u) | mean | range | count | |
| 63 | +|:----------------:|:----:|:-----:|:-----:| |
| 64 | +| Regressions ❌ <br /> (primary) | - | - | 0 | |
| 65 | +| Regressions ❌ <br /> (secondary) | - | - | 0 | |
| 66 | +| Improvements ✅ <br /> (primary) | -0.3% | [-0.7%, -0.2%] | 62 | |
| 67 | +| Improvements ✅ <br /> (secondary) | -0.6% | [-1.6%, -0.2%] | 41 | |
| 68 | +| All ❌✅ (primary) | -0.3% | [-0.7%, -0.2%] | 62 | |
| 69 | + |
| 70 | + |
| 71 | +Rollup of 10 pull requests [#102150](https://github.com/rust-lang/rust/pull/102150) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=77e7e88567691068f5fba288618023368882d60b&end=bc4d574ff2ffcfe76db36116cc4f193384065985&stat=instructions:u) |
| 72 | + |
| 73 | +| (instructions:u) | mean | range | count | |
| 74 | +|:----------------:|:----:|:-----:|:-----:| |
| 75 | +| Regressions ❌ <br /> (primary) | - | - | 0 | |
| 76 | +| Regressions ❌ <br /> (secondary) | - | - | 0 | |
| 77 | +| Improvements ✅ <br /> (primary) | -0.3% | [-0.4%, -0.2%] | 4 | |
| 78 | +| Improvements ✅ <br /> (secondary) | - | - | 0 | |
| 79 | +| All ❌✅ (primary) | -0.3% | [-0.4%, -0.2%] | 4 | |
| 80 | + |
| 81 | + |
| 82 | +Use internal iteration in `Iterator` comparison methods [#100845](https://github.com/rust-lang/rust/pull/100845) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=e1c28e0c857280ce829beab16ef6082cd518db98&end=06968954f7e11454d49377629bb57d13253384b9&stat=instructions:u) |
| 83 | + |
| 84 | +| (instructions:u) | mean | range | count | |
| 85 | +|:----------------:|:----:|:-----:|:-----:| |
| 86 | +| Regressions ❌ <br /> (primary) | - | - | 0 | |
| 87 | +| Regressions ❌ <br /> (secondary) | - | - | 0 | |
| 88 | +| Improvements ✅ <br /> (primary) | -1.1% | [-1.1%, -1.1%] | 1 | |
| 89 | +| Improvements ✅ <br /> (secondary) | - | - | 0 | |
| 90 | +| All ❌✅ (primary) | -1.1% | [-1.1%, -1.1%] | 1 | |
| 91 | + |
| 92 | + |
| 93 | +Move DepKindStruct from rustc_middle to rustc_query_system [#101710](https://github.com/rust-lang/rust/pull/101710) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=f5193a9fcc73dc09e41a90c5a2c97fc9acc16032&end=ff40f2ec95923c4d45366e85bcff17d75df68d68&stat=instructions:u) |
| 94 | + |
| 95 | +| (instructions:u) | mean | range | count | |
| 96 | +|:----------------:|:----:|:-----:|:-----:| |
| 97 | +| Regressions ❌ <br /> (primary) | - | - | 0 | |
| 98 | +| Regressions ❌ <br /> (secondary) | - | - | 0 | |
| 99 | +| Improvements ✅ <br /> (primary) | -0.5% | [-0.9%, -0.2%] | 66 | |
| 100 | +| Improvements ✅ <br /> (secondary) | -0.4% | [-0.7%, -0.2%] | 18 | |
| 101 | +| All ❌✅ (primary) | -0.5% | [-0.9%, -0.2%] | 66 | |
| 102 | + |
| 103 | + |
| 104 | +Rollup of 5 pull requests [#102297](https://github.com/rust-lang/rust/pull/102297) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=fe217c28ffc6955f0927d8e8715d43d727debe5a&end=72f4923979979abb5d6b975353e9b3053d257e60&stat=instructions:u) |
| 105 | + |
| 106 | +| (instructions:u) | mean | range | count | |
| 107 | +|:----------------:|:----:|:-----:|:-----:| |
| 108 | +| Regressions ❌ <br /> (primary) | - | - | 0 | |
| 109 | +| Regressions ❌ <br /> (secondary) | - | - | 0 | |
| 110 | +| Improvements ✅ <br /> (primary) | -0.7% | [-0.7%, -0.7%] | 1 | |
| 111 | +| Improvements ✅ <br /> (secondary) | -1.3% | [-1.5%, -1.2%] | 6 | |
| 112 | +| All ❌✅ (primary) | -0.7% | [-0.7%, -0.7%] | 1 | |
| 113 | + |
| 114 | + |
| 115 | +Fix lint scoping for let-else. [#102257](https://github.com/rust-lang/rust/pull/102257) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=e1d7dec558d863fb76f98453088b36cb1a926d48&end=1d1f1426604b7d79138cdfbb31f82f7f44756fba&stat=instructions:u) |
| 116 | + |
| 117 | +| (instructions:u) | mean | range | count | |
| 118 | +|:----------------:|:----:|:-----:|:-----:| |
| 119 | +| Regressions ❌ <br /> (primary) | - | - | 0 | |
| 120 | +| Regressions ❌ <br /> (secondary) | - | - | 0 | |
| 121 | +| Improvements ✅ <br /> (primary) | -0.7% | [-0.7%, -0.7%] | 1 | |
| 122 | +| Improvements ✅ <br /> (secondary) | -1.4% | [-1.6%, -1.2%] | 6 | |
| 123 | +| All ❌✅ (primary) | -0.7% | [-0.7%, -0.7%] | 1 | |
| 124 | + |
| 125 | + |
| 126 | +Improve code example for Option::unwrap_or_default [#102283](https://github.com/rust-lang/rust/pull/102283) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=8b705839cd656d202e920efa8769cbe43a5ee269&end=f3a6fbf2f2e898ca4d788b3e686726fa9770c676&stat=instructions:u) |
| 127 | + |
| 128 | +| (instructions:u) | mean | range | count | |
| 129 | +|:----------------:|:----:|:-----:|:-----:| |
| 130 | +| Regressions ❌ <br /> (primary) | - | - | 0 | |
| 131 | +| Regressions ❌ <br /> (secondary) | - | - | 0 | |
| 132 | +| Improvements ✅ <br /> (primary) | -0.7% | [-0.7%, -0.7%] | 1 | |
| 133 | +| Improvements ✅ <br /> (secondary) | -1.3% | [-1.6%, -1.2%] | 6 | |
| 134 | +| All ❌✅ (primary) | -0.7% | [-0.7%, -0.7%] | 1 | |
| 135 | + |
| 136 | + |
| 137 | +#### Mixed |
| 138 | + |
| 139 | +Revert perf-regression 101620 [#102064](https://github.com/rust-lang/rust/pull/102064) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=199fe1d169b5aeeca0e527ded26542b7a05ebd79&end=bb5a01617589b5e3ece5a36435fc285bfd13c9a4&stat=instructions:u) |
| 140 | + |
| 141 | +| (instructions:u) | mean | range | count | |
| 142 | +|:----------------:|:----:|:-----:|:-----:| |
| 143 | +| Regressions ❌ <br /> (primary) | 5.6% | [0.3%, 33.5%] | 33 | |
| 144 | +| Regressions ❌ <br /> (secondary) | 1.1% | [0.3%, 1.5%] | 11 | |
| 145 | +| Improvements ✅ <br /> (primary) | -3.7% | [-12.3%, -0.3%] | 129 | |
| 146 | +| Improvements ✅ <br /> (secondary) | -4.1% | [-19.0%, -0.2%] | 121 | |
| 147 | +| All ❌✅ (primary) | -1.8% | [-12.3%, 33.5%] | 162 | |
| 148 | + |
| 149 | +This fixes a perf regression from last week and the overall trend is an improvement, so as expected. |
| 150 | + |
| 151 | +Use function pointers instead of macro-unrolled loops in rustc_query_impl [#101785](https://github.com/rust-lang/rust/pull/101785) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=ff40f2ec95923c4d45366e85bcff17d75df68d68&end=3288d3a305ad15cfcdcd9ef72404be6d2a2887b5&stat=instructions:u) |
| 152 | + |
| 153 | +| (instructions:u) | mean | range | count | |
| 154 | +|:----------------:|:----:|:-----:|:-----:| |
| 155 | +| Regressions ❌ <br /> (primary) | - | - | 0 | |
| 156 | +| Regressions ❌ <br /> (secondary) | 1.2% | [1.2%, 1.2%] | 2 | |
| 157 | +| Improvements ✅ <br /> (primary) | -0.4% | [-0.4%, -0.4%] | 1 | |
| 158 | +| Improvements ✅ <br /> (secondary) | -1.1% | [-1.5%, -0.6%] | 9 | |
| 159 | +| All ❌✅ (primary) | -0.4% | [-0.4%, -0.4%] | 1 | |
| 160 | + |
| 161 | +Overall mixed results and generally a slight improvement. The seemingly more |
| 162 | +important goal of reducing bootstrap times isn't really achieved by this PR |
| 163 | +though it may help future iteration on these functions by avoiding some LLVM sensitivity. |
| 164 | + |
| 165 | +Rollup of 5 pull requests [#102324](https://github.com/rust-lang/rust/pull/102324) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=1d1f1426604b7d79138cdfbb31f82f7f44756fba&end=8b705839cd656d202e920efa8769cbe43a5ee269&stat=instructions:u) |
| 166 | + |
| 167 | +| (instructions:u) | mean | range | count | |
| 168 | +|:----------------:|:----:|:-----:|:-----:| |
| 169 | +| Regressions ❌ <br /> (primary) | 0.7% | [0.7%, 0.7%] | 1 | |
| 170 | +| Regressions ❌ <br /> (secondary) | 1.4% | [1.3%, 1.6%] | 6 | |
| 171 | +| Improvements ✅ <br /> (primary) | -0.7% | [-0.9%, -0.6%] | 6 | |
| 172 | +| Improvements ✅ <br /> (secondary) | - | - | 0 | |
| 173 | +| All ❌✅ (primary) | -0.5% | [-0.9%, 0.7%] | 7 | |
| 174 | + |
| 175 | +keccak, the primary regression, is within its suspected noise level bar. |
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