Tweak VecCache to improve performance by Zoxc · Pull Request #138405 · rust-lang/rust (original) (raw)
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This has some tweaks to VecCache to improve performance.
- It saves a
compare_exchangeincompleteusing the newput_uniquefunction. - It removes bound checks on entries. These are instead checked in the
slot_index_exhaustivetest. initialize_bucketis outlined and tuned for that.
r? @Noratrieb
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bors added a commit to rust-lang-ci/rust that referenced this pull request
Tweak VecCache to improve performance
This has some tweaks to VecCache to improve performance.
- It saves a
compare_exchangeincompleteusing the newput_uniquefunction. - It removes bound checks on entries. These are instead checked in the
slot_index_exhaustivetest. initialize_bucketis outlined and tuned for that.
cc @Mark-Simulacrum
☀️ Try build successful - checks-actions
Build commit: 0b0612c (0b0612c92faadc7268901ca7f18b6859d25f4eba)
This comment has been minimized.
| } |
|---|
| #[cold] |
| fn initialize_bucket(&self, bucket: &AtomicPtr<Slot>) -> *mut Slot { |
| #[inline(never)] |
| fn initialize_bucket(bucket: &AtomicPtr<Slot>, bucket_idx: usize) -> *mut Slot { |
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Why this change?
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It avoids Self needing it exist when not inlined, as the needed information can be passed in registers instead.
Finished benchmarking commit (0b0612c): comparison URL.
Overall result: ❌✅ regressions and improvements - please read the text below
Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR may lead to changes in compiler perf.
Next Steps: If you can justify the regressions found in this try perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please fix the regressions and do another perf run. If the next run shows neutral or positive results, the label will be automatically removed.
@bors rollup=never
@rustbot label: -S-waiting-on-perf +perf-regression
Instruction count
This is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.
| mean | range | count | |
|---|---|---|---|
| Regressions ❌ (primary) | - | - | 0 |
| Regressions ❌ (secondary) | 0.9% | [0.2%, 1.8%] | 15 |
| Improvements ✅ (primary) | -0.4% | [-0.9%, -0.2%] | 140 |
| Improvements ✅ (secondary) | -0.6% | [-1.2%, -0.2%] | 42 |
| All ❌✅ (primary) | -0.4% | [-0.9%, -0.2%] | 140 |
Max RSS (memory usage)
Results (primary -2.0%)
This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.
| mean | range | count | |
|---|---|---|---|
| Regressions ❌ (primary) | - | - | 0 |
| Regressions ❌ (secondary) | - | - | 0 |
| Improvements ✅ (primary) | -2.0% | [-2.8%, -1.2%] | 2 |
| Improvements ✅ (secondary) | - | - | 0 |
| All ❌✅ (primary) | -2.0% | [-2.8%, -1.2%] | 2 |
Cycles
Results (primary 4.1%, secondary -3.1%)
This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.
| mean | range | count | |
|---|---|---|---|
| Regressions ❌ (primary) | 6.8% | [1.6%, 13.7%] | 13 |
| Regressions ❌ (secondary) | - | - | 0 |
| Improvements ✅ (primary) | -1.7% | [-2.1%, -1.4%] | 6 |
| Improvements ✅ (secondary) | -3.1% | [-3.5%, -2.5%] | 3 |
| All ❌✅ (primary) | 4.1% | [-2.1%, 13.7%] | 19 |
Binary size
This benchmark run did not return any relevant results for this metric.
Bootstrap: 779.667s -> 779.823s (0.02%)
Artifact size: 365.24 MiB -> 365.04 MiB (-0.06%)
Local results:
| Benchmark | Before | After | Before | After | Before | After | |||
|---|---|---|---|---|---|---|---|---|---|
| Time | Time | % | Physical Memory | Physical Memory | % | Committed Memory | Committed Memory | % | |
| 🟣 clap:check | 1.4028s | 1.3962s | -0.47% | 147.60 MiB | 147.57 MiB | -0.02% | 192.07 MiB | 192.06 MiB | -0.01% |
| 🟣 hyper:check | 0.2335s | 0.2321s | -0.58% | 80.01 MiB | 79.95 MiB | -0.07% | 121.83 MiB | 121.83 MiB | -0.01% |
| 🟣 regex:check | 0.7944s | 0.7918s | -0.33% | 108.43 MiB | 108.50 MiB | 0.07% | 146.66 MiB | 146.80 MiB | 0.09% |
| 🟣 syn:check | 1.3258s | 1.3183s | -0.57% | 141.93 MiB | 141.92 MiB | -0.01% | 180.31 MiB | 180.36 MiB | 0.03% |
| Total | 3.7565s | 3.7385s | -0.48% | 477.97 MiB | 477.95 MiB | -0.00% | 640.87 MiB | 641.04 MiB | 0.03% |
| Summary | 1.0000s | 0.9951s | -0.49% | 1 byte | 1.00 bytes | -0.01% | 1 byte | 1.00 bytes | 0.03% |
Looks like something might be up with html5ever.
I can't reproduce the html5ever regression locally:
| Benchmark | Before | After | Before | After | Before | After | |||
|---|---|---|---|---|---|---|---|---|---|
| Time | Time | % | Physical Memory | Physical Memory | % | Committed Memory | Committed Memory | % | |
| 🟣 html5ever:check | 0.6299s | 0.6256s | -0.67% | 104.10 MiB | 103.98 MiB | -0.11% | 147.54 MiB | 147.58 MiB | 0.02% |
| Total | 0.6299s | 0.6256s | -0.67% | 104.10 MiB | 103.98 MiB | -0.11% | 147.54 MiB | 147.58 MiB | 0.02% |
| Summary | 1.0000s | 0.9933s | -0.67% | 1 byte | 1.00 bytes | -0.11% | 1 byte | 1.00 bytes | 0.02% |
Cycles are noisy, although this was high above the threshold. Let's try again, just in case it was a fluke.
@bors try @rust-timer queue
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bors added a commit to rust-lang-ci/rust that referenced this pull request
Tweak VecCache to improve performance
This has some tweaks to VecCache to improve performance.
- It saves a
compare_exchangeincompleteusing the newput_uniquefunction. - It removes bound checks on entries. These are instead checked in the
slot_index_exhaustivetest. initialize_bucketis outlined and tuned for that.
cc @Mark-Simulacrum
☀️ Try build successful - checks-actions
Build commit: d06bb14 (d06bb14bb9c4c2e005971e2f02d13bb79af6845e)
This comment has been minimized.
Finished benchmarking commit (d06bb14): comparison URL.
Overall result: ❌✅ regressions and improvements - please read the text below
Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR may lead to changes in compiler perf.
Next Steps: If you can justify the regressions found in this try perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please fix the regressions and do another perf run. If the next run shows neutral or positive results, the label will be automatically removed.
@bors rollup=never
@rustbot label: -S-waiting-on-perf +perf-regression
Instruction count
This is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.
| mean | range | count | |
|---|---|---|---|
| Regressions ❌ (primary) | - | - | 0 |
| Regressions ❌ (secondary) | 1.3% | [0.6%, 1.8%] | 10 |
| Improvements ✅ (primary) | -0.4% | [-0.9%, -0.2%] | 143 |
| Improvements ✅ (secondary) | -0.6% | [-1.3%, -0.2%] | 43 |
| All ❌✅ (primary) | -0.4% | [-0.9%, -0.2%] | 143 |
Max RSS (memory usage)
This benchmark run did not return any relevant results for this metric.
Cycles
Results (primary -1.5%, secondary -2.1%)
This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.
| mean | range | count | |
|---|---|---|---|
| Regressions ❌ (primary) | - | - | 0 |
| Regressions ❌ (secondary) | - | - | 0 |
| Improvements ✅ (primary) | -1.5% | [-1.5%, -1.5%] | 1 |
| Improvements ✅ (secondary) | -2.1% | [-2.1%, -2.1%] | 1 |
| All ❌✅ (primary) | -1.5% | [-1.5%, -1.5%] | 1 |
Binary size
This benchmark run did not return any relevant results for this metric.
Bootstrap: 779.458s -> 779.323s (-0.02%)
Artifact size: 365.27 MiB -> 365.05 MiB (-0.06%)
Looks like it was a fluke after all.
So, is this patch actually ... needed? Thanks
