From f9b3dec22cbddfc7a6b50fca867b6d1939e0538f Mon Sep 17 00:00:00 2001 From: Ryan Levick Date: Tue, 3 Jan 2023 18:50:38 +0100 Subject: [PATCH] Add triage for 2023-01-03 --- triage/2023-01-03.md | 121 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 121 insertions(+) create mode 100644 triage/2023-01-03.md diff --git a/triage/2023-01-03.md b/triage/2023-01-03.md new file mode 100644 index 000000000..777339c6f --- /dev/null +++ b/triage/2023-01-03.md @@ -0,0 +1,121 @@ +# 2023-01-03 Triage Log + +Fairly busy week with some massive performance improvements at the expense of some significant albeit smaller regressions. The main wins came in a long-standing PR from @cjgillot to enable encoding spans in metadata relative to their enclosing item. This causes more work in full compilation which causes some regressions up to 5% but can lead to very large wins in incremental compilation scenarios (up to ~70%). For example, the clap crate compiles 68% faster after a small 1 line change than it did previously. + +Triage done by **@rylev**. +Revision range: [b38a6d..b43596](https://perf.rust-lang.org/?start=b38a6d373cb254697411147c0e49cd2e84864258&end=b435960c4cfd3975651c7051be56d7f5d6c201ab&absolute=false&stat=instructions%3Au) + +**Summary**: + +| (instructions:u) | mean | range | count | +|:----------------------------------:|:-----:|:---------------:|:-----:| +| Regressions ❌
(primary) | 1.6% | [0.3%, 4.6%] | 97 | +| Regressions ❌
(secondary) | 1.8% | [0.2%, 7.6%] | 60 | +| Improvements ✅
(primary) | -9.7% | [-68.7%, -0.2%] | 53 | +| Improvements ✅
(secondary) | -1.7% | [-15.3%, -0.1%] | 62 | +| All ❌✅ (primary) | -2.4% | [-68.7%, 4.6%] | 150 | + +1 Regressions, 1 Improvements, 4 Mixed; 1 of them in rollups +47 artifact comparisons made in total + +#### Regressions + +Rollup of 8 pull requests [#106228](https://github.com/rust-lang/rust/pull/106228) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=270c94e484e19764a2832ef918c95224eb3f17c7&end=9709a438721d679572f0f7c389cd1fa60922fbef&stat=instructions:u) + +| (instructions:u) | mean | range | count | +|:----------------------------------:|:----:|:------------:|:-----:| +| Regressions ❌
(primary) | 0.4% | [0.2%, 0.6%] | 7 | +| Regressions ❌
(secondary) | - | - | 0 | +| Improvements ✅
(primary) | - | - | 0 | +| Improvements ✅
(secondary) | - | - | 0 | +| All ❌✅ (primary) | 0.4% | [0.2%, 0.6%] | 7 | +- Kicked off a perf run on the only likely culprit. The regression is small enough that I don't think it's a big deal if we don't figure this out. + +Allow trait method paths to satisfy const Fn bounds [#106210](https://github.com/rust-lang/rust/pull/106210) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=2c7536eaae59b44ff5259183ca98384129d69dd0&end=973a4db8d590d1ddfa4d07bd216aeffd28ba354e&stat=instructions:u) + +| (instructions:u) | mean | range | count | +|:----------------------------------:|:-----:|:--------------:|:-----:| +| Regressions ❌
(primary) | 0.3% | [0.2%, 0.5%] | 16 | +| Regressions ❌
(secondary) | 0.4% | [0.2%, 0.7%] | 16 | +| Improvements ✅
(primary) | - | - | 0 | +| Improvements ✅
(secondary) | -1.4% | [-1.4%, -1.4%] | 1 | +| All ❌✅ (primary) | 0.3% | [0.2%, 0.5%] | 16 | +- Massive amount of noise reversed in [#106268](https://github.com/rust-lang/rust/pull/106268). No idea where this noise comes from. + + +#### Improvements + + +fix comment for `TokenCursor::desugar` [#106268](https://github.com/rust-lang/rust/pull/106268) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=808be91da07c91e4d6006cca0ad78385785a741e&end=e5e5fcb0b758fcf7f149cc9206155dcfa18ec909&stat=instructions:u) + +| (instructions:u) | mean | range | count | +|:----------------------------------:|:-----:|:--------------:|:-----:| +| Regressions ❌
(primary) | - | - | 0 | +| Regressions ❌
(secondary) | - | - | 0 | +| Improvements ✅
(primary) | -0.3% | [-0.5%, -0.2%] | 17 | +| Improvements ✅
(secondary) | -0.3% | [-0.7%, -0.2%] | 15 | +| All ❌✅ (primary) | -0.3% | [-0.5%, -0.2%] | 17 | +- Massive amount of noise coming in [#106210](https://github.com/rust-lang/rust/pull/106210) reversed here. No idea where this noise comes from. + + +Abolish `QueryVTable` in favour of more assoc items on `QueryConfig` [#106307](https://github.com/rust-lang/rust/pull/106307) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=23b1cc197a3a6d0c1ab78a5c6e7cdad17681f1c9&end=d6f99e535a301a421dfee52a7c25bb4bdf420344&stat=instructions:u) + +| (instructions:u) | mean | range | count | +|:----------------------------------:|:-----:|:--------------:|:-----:| +| Regressions ❌
(primary) | - | - | 0 | +| Regressions ❌
(secondary) | 0.6% | [0.4%, 1.0%] | 4 | +| Improvements ✅
(primary) | -0.5% | [-1.0%, -0.2%] | 63 | +| Improvements ✅
(secondary) | -0.6% | [-1.3%, -0.4%] | 60 | +| All ❌✅ (primary) | -0.5% | [-1.0%, -0.2%] | 63 | + + +#### Mixed + +Catch panics/unwinding in destruction of TLS values [#105426](https://github.com/rust-lang/rust/pull/105426) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=f6cc345be403d481b4518e151218118c2a9eb4bb&end=7c991868c60a4afc1ee6334b912ea96061a2c98d&stat=instructions:u) + +| (instructions:u) | mean | range | count | +|:----------------------------------:|:-----:|:---------------:|:-----:| +| Regressions ❌
(primary) | 0.7% | [0.3%, 1.9%] | 11 | +| Regressions ❌
(secondary) | - | - | 0 | +| Improvements ✅
(primary) | -0.3% | [-0.6%, -0.2%] | 41 | +| Improvements ✅
(secondary) | -1.8% | [-14.6%, -0.2%] | 31 | +| All ❌✅ (primary) | -0.1% | [-0.6%, 1.9%] | 52 | +- Very much unsure where the performance changes are coming from. Some show LLVM regressions but not all. LLVM also does not explain the improvements. +- Ask [in the PR](https://github.com/rust-lang/rust/pull/105426#issuecomment-1370051574) for thoughts. + + +Use some more `const_eval_select` in pointer methods for compile times [#106275](https://github.com/rust-lang/rust/pull/106275) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=726bbfc8f0d6eb431dfa620c1c8fc3848020cd3c&end=dd01a163c1cff9461ddd85e7b3c2c0109657658f&stat=instructions:u) + +| (instructions:u) | mean | range | count | +|:----------------------------------:|:-----:|:--------------:|:-----:| +| Regressions ❌
(primary) | 0.4% | [0.4%, 0.4%] | 1 | +| Regressions ❌
(secondary) | 0.7% | [0.6%, 0.9%] | 2 | +| Improvements ✅
(primary) | -0.5% | [-0.9%, -0.2%] | 28 | +| Improvements ✅
(secondary) | -0.8% | [-0.8%, -0.7%] | 3 | +| All ❌✅ (primary) | -0.4% | [-0.9%, 0.4%] | 29 | +- Author investigated why this might have caused a regression in `regex` and found nothing. The gains much outweigh the regressions so we should be fine keeping it. + + +Encode spans relative to the enclosing item -- enable on nightly [#84762](https://github.com/rust-lang/rust/pull/84762) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=f89003eda8917ff99f8ee3fb5c812310a58c014b&end=fb9dfa8ceffb985105be3176d7ed2f99515ea377&stat=instructions:u) + +| (instructions:u) | mean | range | count | +|:----------------------------------:|:------:|:---------------:|:-----:| +| Regressions ❌
(primary) | 1.7% | [0.2%, 5.0%] | 108 | +| Regressions ❌
(secondary) | 1.8% | [0.2%, 7.6%] | 90 | +| Improvements ✅
(primary) | -20.0% | [-68.9%, -0.6%] | 25 | +| Improvements ✅
(secondary) | -2.7% | [-4.8%, -1.5%] | 11 | +| All ❌✅ (primary) | -2.4% | [-68.9%, 5.0%] | 133 | +- There was an [FCP](https://github.com/rust-lang/rust/pull/84762#issuecomment-1327518372) to decide whether the trade off of some regressions for some huge incremental performance wins was worth it. +- This FCP passed and so the PR was merged. + + +Reenable limited top-down MIR inlining [#106364](https://github.com/rust-lang/rust/pull/106364) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=d6f99e535a301a421dfee52a7c25bb4bdf420344&end=67d16171d7eebc08057a46aeed887252e7cc286b&stat=instructions:u) + +| (instructions:u) | mean | range | count | +|:----------------------------------:|:-----:|:--------------:|:-----:| +| Regressions ❌
(primary) | 0.5% | [0.3%, 1.1%] | 4 | +| Regressions ❌
(secondary) | 0.6% | [0.5%, 0.6%] | 4 | +| Improvements ✅
(primary) | -0.6% | [-1.2%, -0.2%] | 9 | +| Improvements ✅
(secondary) | -0.9% | [-2.4%, -0.2%] | 18 | +| All ❌✅ (primary) | -0.2% | [-1.2%, 1.1%] | 13 | +- As pointed out [here](https://github.com/rust-lang/rust/pull/106364#issuecomment-1369111291) this was effectively a performance wash with regressions and improvements canceling themselves out.