-
Notifications
You must be signed in to change notification settings - Fork 19
chore(benchmarks): add allocation size tracking allocator #1905
New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
Merged
gh-worker-dd-mergequeue-cf854d
merged 1 commit into
main
from
ban/add-counting-allocator
Apr 21, 2026
Merged
Changes from all commits
Commits
File filter
Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
There are no files selected for viewing
Some generated files are not rendered by default. Learn more about how customized files appear on GitHub.
Oops, something went wrong.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,333 @@ | ||
| // Copyright 2021-Present Datadog, Inc. https://www.datadoghq.com/ | ||
| // SPDX-License-Identifier: Apache-2.0 | ||
|
|
||
| //! Scaffolding for memory usage benchmarks. | ||
| //! | ||
| //! See the `ReportingAllocator` type and `memory_allocated_measurement` for usage. | ||
|
|
||
| #![allow(missing_docs)] | ||
|
|
||
| use std::{ | ||
| alloc::{GlobalAlloc, System}, | ||
| cell::Cell, | ||
| time::Duration, | ||
| }; | ||
|
|
||
| use criterion::{Criterion, Throughput}; | ||
|
|
||
| pub trait MeasurementName { | ||
| fn name() -> &'static str; | ||
| } | ||
|
|
||
| impl MeasurementName for criterion::measurement::WallTime { | ||
| fn name() -> &'static str { | ||
| "wall_time" | ||
| } | ||
| } | ||
|
|
||
| pub fn memory_allocated_measurement( | ||
| global_alloc: &'static ReportingAllocator<System>, | ||
| ) -> Criterion<AllocatedBytesMeasurement<System>> { | ||
| Criterion::default() | ||
| .with_measurement(AllocatedBytesMeasurement(Cell::new(false), global_alloc)) | ||
| .measurement_time(Duration::from_millis(1)) | ||
| .warm_up_time(Duration::from_millis(1)) | ||
| .without_plots() | ||
| .plotting_backend(criterion::PlottingBackend::None) | ||
| .sample_size(10) | ||
| } | ||
|
|
||
| #[derive(Debug)] | ||
| struct AllocStats { | ||
| allocated_bytes: usize, | ||
| #[allow(dead_code)] | ||
| allocations: usize, | ||
| } | ||
|
|
||
| pub struct ReportingAllocator<T: GlobalAlloc> { | ||
| alloc: T, | ||
| allocated_bytes: std::sync::atomic::AtomicUsize, | ||
| allocations: std::sync::atomic::AtomicUsize, | ||
| } | ||
|
|
||
| impl<T: GlobalAlloc> ReportingAllocator<T> { | ||
| pub const fn new(alloc: T) -> Self { | ||
| Self { | ||
| alloc, | ||
| allocated_bytes: std::sync::atomic::AtomicUsize::new(0), | ||
| allocations: std::sync::atomic::AtomicUsize::new(0), | ||
| } | ||
| } | ||
|
|
||
| fn stats(&self) -> AllocStats { | ||
| AllocStats { | ||
| allocated_bytes: self | ||
| .allocated_bytes | ||
| .load(std::sync::atomic::Ordering::Relaxed), | ||
| allocations: self.allocations.load(std::sync::atomic::Ordering::Relaxed), | ||
| } | ||
| } | ||
| } | ||
|
|
||
| unsafe impl<T: GlobalAlloc> GlobalAlloc for ReportingAllocator<T> { | ||
| unsafe fn alloc(&self, layout: std::alloc::Layout) -> *mut u8 { | ||
| self.allocated_bytes | ||
| .fetch_add(layout.size(), std::sync::atomic::Ordering::Relaxed); | ||
| self.allocations | ||
| .fetch_add(1, std::sync::atomic::Ordering::Relaxed); | ||
| self.alloc.alloc(layout) | ||
| } | ||
|
|
||
| unsafe fn dealloc(&self, ptr: *mut u8, layout: std::alloc::Layout) { | ||
| self.alloc.dealloc(ptr, layout); | ||
| } | ||
| } | ||
|
|
||
| pub struct AllocatedBytesMeasurement<T: GlobalAlloc + 'static>( | ||
| Cell<bool>, | ||
| &'static ReportingAllocator<T>, | ||
| ); | ||
|
|
||
| impl<T: GlobalAlloc> MeasurementName for AllocatedBytesMeasurement<T> { | ||
| fn name() -> &'static str { | ||
| "allocated_bytes" | ||
| } | ||
| } | ||
|
|
||
| impl<T: GlobalAlloc> criterion::measurement::Measurement for AllocatedBytesMeasurement<T> { | ||
| type Intermediate = usize; | ||
|
|
||
| type Value = usize; | ||
|
|
||
| fn start(&self) -> Self::Intermediate { | ||
| self.1.stats().allocated_bytes | ||
| } | ||
|
|
||
| fn end(&self, i: Self::Intermediate) -> Self::Value { | ||
| self.1.stats().allocated_bytes - i | ||
| } | ||
|
|
||
| fn add(&self, v1: &Self::Value, v2: &Self::Value) -> Self::Value { | ||
| *v1 + *v2 | ||
| } | ||
|
|
||
| fn zero(&self) -> Self::Value { | ||
| 0 | ||
| } | ||
|
|
||
| fn to_f64(&self, value: &Self::Value) -> f64 { | ||
| let b = self.0.get(); | ||
| self.0.set(!b); | ||
| // Criterion does not handle all-identical measurement values well, and since | ||
| // allocation is deterministic that tends to happen a lot. Add a small +/- epsilon | ||
| // so each pair of measurements differs slightly without skewing the distribution. | ||
| *value as f64 + if b { 0.01 } else { -0.01 } | ||
| } | ||
|
|
||
| fn formatter(&self) -> &dyn criterion::measurement::ValueFormatter { | ||
| &AllocationFormatter | ||
| } | ||
| } | ||
|
|
||
| struct AllocationFormatter; | ||
|
|
||
| impl criterion::measurement::ValueFormatter for AllocationFormatter { | ||
| fn scale_values(&self, typical_value: f64, values: &mut [f64]) -> &'static str { | ||
| let log_scale: f64 = typical_value.log10().round(); | ||
| if log_scale.is_infinite() || log_scale.is_nan() || log_scale < 0.0 { | ||
| return "b"; | ||
| } | ||
| let scale = (log_scale as i32 / 3).min(4); | ||
| values.iter_mut().for_each(|v| *v /= 10_f64.powi(scale * 3)); | ||
| match scale { | ||
| 0 => "b", | ||
| 1 => "Kb", | ||
| 2 => "Mb", | ||
| 3 => "Gb", | ||
| _ => "Tb", | ||
| } | ||
| } | ||
|
|
||
| fn scale_throughputs( | ||
| &self, | ||
| _typical_value: f64, | ||
| throughput: &criterion::Throughput, | ||
| _values: &mut [f64], | ||
| ) -> &'static str { | ||
| match throughput { | ||
| Throughput::Bytes(_) => "B/s", | ||
| Throughput::BytesDecimal(_) => "B/s", | ||
| Throughput::Elements(_) => "elements/s", | ||
| } | ||
| } | ||
|
|
||
| fn scale_for_machines(&self, _values: &mut [f64]) -> &'static str { | ||
| "b" | ||
| } | ||
| } | ||
|
|
||
| #[cfg(test)] | ||
| mod tests { | ||
| use super::*; | ||
| use criterion::measurement::{Measurement, ValueFormatter}; | ||
| use std::alloc::{GlobalAlloc, Layout, System}; | ||
|
|
||
| static SHARED: ReportingAllocator<System> = ReportingAllocator::new(System); | ||
|
|
||
| // --- ReportingAllocator --- | ||
|
|
||
| #[test] | ||
| fn new_starts_at_zero() { | ||
| let a = ReportingAllocator::new(System); | ||
| let s = a.stats(); | ||
| assert_eq!(s.allocated_bytes, 0); | ||
| assert_eq!(s.allocations, 0); | ||
| } | ||
|
|
||
| #[test] | ||
| fn alloc_increments_both_counters() { | ||
| let a = ReportingAllocator::new(System); | ||
| let layout = Layout::from_size_align(64, 8).unwrap(); | ||
| let ptr = unsafe { a.alloc(layout) }; | ||
| assert!(!ptr.is_null()); | ||
| assert_eq!(a.stats().allocated_bytes, 64); | ||
| assert_eq!(a.stats().allocations, 1); | ||
| unsafe { a.dealloc(ptr, layout) }; | ||
| } | ||
|
|
||
| #[test] | ||
| fn dealloc_does_not_change_counters() { | ||
| let a = ReportingAllocator::new(System); | ||
| let layout = Layout::from_size_align(32, 8).unwrap(); | ||
| let ptr = unsafe { a.alloc(layout) }; | ||
| let bytes_after_alloc = a.stats().allocated_bytes; | ||
| unsafe { a.dealloc(ptr, layout) }; | ||
| assert_eq!(a.stats().allocated_bytes, bytes_after_alloc); | ||
| assert_eq!(a.stats().allocations, 1); | ||
| } | ||
|
|
||
| #[test] | ||
| fn multiple_allocs_accumulate() { | ||
| let a = ReportingAllocator::new(System); | ||
| let l1 = Layout::from_size_align(16, 8).unwrap(); | ||
| let l2 = Layout::from_size_align(32, 8).unwrap(); | ||
| let p1 = unsafe { a.alloc(l1) }; | ||
| let p2 = unsafe { a.alloc(l2) }; | ||
| assert_eq!(a.stats().allocated_bytes, 48); | ||
| assert_eq!(a.stats().allocations, 2); | ||
| unsafe { | ||
| a.dealloc(p1, l1); | ||
| a.dealloc(p2, l2); | ||
| } | ||
| } | ||
|
|
||
| // --- AllocatedBytesMeasurement --- | ||
|
|
||
| #[test] | ||
| fn measurement_zero_and_add() { | ||
| let m = AllocatedBytesMeasurement(Cell::new(false), &SHARED); | ||
| assert_eq!(m.zero(), 0); | ||
| assert_eq!(m.add(&100, &200), 300); | ||
| } | ||
|
|
||
| #[test] | ||
| fn measurement_start_end_tracks_delta() { | ||
| let m = AllocatedBytesMeasurement(Cell::new(false), &SHARED); | ||
| let start = m.start(); | ||
| let layout = Layout::from_size_align(256, 8).unwrap(); | ||
| let ptr = unsafe { SHARED.alloc(layout) }; | ||
| // Other tests may also allocate via SHARED concurrently, so allow >= 256. | ||
| assert!(m.end(start) >= 256); | ||
| unsafe { SHARED.dealloc(ptr, layout) }; | ||
| } | ||
|
|
||
| #[test] | ||
| fn measurement_to_f64_alternates_epsilon() { | ||
| let m = AllocatedBytesMeasurement(Cell::new(false), &SHARED); | ||
| // Initial state: Cell = false → first result is value - 0.01 | ||
| assert!((m.to_f64(&1000) - 999.99).abs() < 1e-9); | ||
| // After first call: Cell = true → result is value + 0.01 | ||
| assert!((m.to_f64(&1000) - 1000.01).abs() < 1e-9); | ||
| // Alternates back | ||
| assert!((m.to_f64(&1000) - 999.99).abs() < 1e-9); | ||
| } | ||
|
|
||
| #[test] | ||
| fn measurement_name() { | ||
| assert_eq!( | ||
| AllocatedBytesMeasurement::<System>::name(), | ||
| "allocated_bytes" | ||
| ); | ||
| } | ||
|
|
||
| // --- AllocationFormatter::scale_values --- | ||
|
|
||
| #[test] | ||
| fn scale_values_zero_returns_bytes() { | ||
| let f = AllocationFormatter; | ||
| let mut v = [42.0_f64]; | ||
| assert_eq!(f.scale_values(0.0, &mut v), "b"); | ||
| } | ||
|
|
||
| #[test] | ||
| fn scale_values_sub_byte_returns_bytes() { | ||
| let f = AllocationFormatter; | ||
| let mut v = [0.5_f64]; | ||
| // log10(0.1) = -1 → negative → "b" | ||
| assert_eq!(f.scale_values(0.1, &mut v), "b"); | ||
| } | ||
|
|
||
| #[test] | ||
| fn scale_values_bytes() { | ||
| let f = AllocationFormatter; | ||
| let mut v = [1.0_f64]; | ||
| assert_eq!(f.scale_values(1.0, &mut v), "b"); | ||
| assert!((v[0] - 1.0).abs() < 1e-9); | ||
| } | ||
|
|
||
| #[test] | ||
| fn scale_values_kilobytes() { | ||
| let f = AllocationFormatter; | ||
| let mut v = [2000.0_f64]; | ||
| assert_eq!(f.scale_values(1000.0, &mut v), "Kb"); | ||
| assert!((v[0] - 2.0).abs() < 1e-9); | ||
| } | ||
|
|
||
| #[test] | ||
| fn scale_values_megabytes() { | ||
| let f = AllocationFormatter; | ||
| let mut v = [3_000_000.0_f64]; | ||
| assert_eq!(f.scale_values(1_000_000.0, &mut v), "Mb"); | ||
| assert!((v[0] - 3.0).abs() < 1e-9); | ||
| } | ||
|
|
||
| #[test] | ||
| fn scale_values_gigabytes() { | ||
| let f = AllocationFormatter; | ||
| let mut v = [4_000_000_000.0_f64]; | ||
| assert_eq!(f.scale_values(1_000_000_000.0, &mut v), "Gb"); | ||
| assert!((v[0] - 4.0).abs() < 1e-9); | ||
| } | ||
|
|
||
| #[test] | ||
| fn scale_values_terabytes() { | ||
| let f = AllocationFormatter; | ||
| let mut v = [5_000_000_000_000.0_f64]; | ||
| assert_eq!(f.scale_values(1_000_000_000_000.0, &mut v), "Tb"); | ||
| assert!((v[0] - 5.0).abs() < 1e-9); | ||
| } | ||
|
|
||
| #[test] | ||
| fn scale_values_very_large_clamps_to_terabytes() { | ||
| let f = AllocationFormatter; | ||
| let mut v = [1e18_f64]; | ||
| assert_eq!(f.scale_values(1e18, &mut v), "Tb"); | ||
| } | ||
|
|
||
| #[test] | ||
| fn scale_for_machines_returns_bytes_unit() { | ||
| let f = AllocationFormatter; | ||
| let mut v = [1000.0_f64]; | ||
| assert_eq!(f.scale_for_machines(&mut v), "b"); | ||
| } | ||
| } |
Oops, something went wrong.
Oops, something went wrong.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
This unnecessary cleanup makes listing or filtering benchmarks lock up on Mac.