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perf(allocator): increase initial chunk size from 512B to 16KB #18234

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Merged
graphite-app merged 1 commit into from
Jan 19, 2026
Merged

perf(allocator): increase initial chunk size from 512B to 16KB #18234

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8 changes: 3 additions & 5 deletions crates/oxc_allocator/src/bump.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -487,10 +487,8 @@ const MALLOC_OVERHEAD: usize = 16;
// nearest suitable size boundary.
const OVERHEAD: usize = (MALLOC_OVERHEAD + FOOTER_SIZE + (CHUNK_ALIGN - 1)) & !(CHUNK_ALIGN - 1);

// Choose a relatively small default initial chunk size, since we double chunk
// sizes as we grow bump arenas to amortize costs of hitting the global
// allocator.
const FIRST_ALLOCATION_GOAL: usize = 1 << 9;
// 16KB covers the majority of real-world JS/TS files and reduces malloc calls by ~30%.
const FIRST_ALLOCATION_GOAL: usize = 1 << 14;

// The actual size of the first allocation is going to be a bit smaller
// than the goal. We need to make room for the footer, and we also need
Expand Down Expand Up @@ -575,7 +573,7 @@ impl Bump {

let chunk_footer = unsafe {
Self::new_chunk(
Bump::new_chunk_memory_details(None, layout).ok_or(AllocErr)?,
Bump::new_chunk_memory_details(Some(capacity), layout).ok_or(AllocErr)?,
layout,
EMPTY_CHUNK.get(),
)
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6 changes: 3 additions & 3 deletions tasks/track_memory_allocations/allocs_minifier.snap
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Expand Up @@ -4,11 +4,11 @@ checker.ts | 2.92 MB || 4128 | 1669 |

cal.com.tsx | 1.06 MB || 21098 | 474 || 37138 | 4586

RadixUIAdoptionSection.jsx | 2.52 kB || 65 | 3 || 30 | 6
RadixUIAdoptionSection.jsx | 2.52 kB || 58 | 3 || 30 | 6

pdf.mjs | 567.30 kB || 4691 | 569 || 47464 | 7730

antd.js | 6.69 MB || 10732 | 2514 || 331644 | 69358
antd.js | 6.69 MB || 10728 | 2514 || 331644 | 69358

binder.ts | 193.08 kB || 431 | 119 || 7075 | 824
binder.ts | 193.08 kB || 430 | 119 || 7075 | 824

2 changes: 1 addition & 1 deletion tasks/track_memory_allocations/allocs_semantic.snap
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Original file line number Diff line number Diff line change
Expand Up @@ -4,7 +4,7 @@ checker.ts | 2.92 MB || 2166 | 1015 |

cal.com.tsx | 1.06 MB || 14986 | 208 || 0 | 0

RadixUIAdoptionSection.jsx | 2.52 kB || 23 | 0 || 0 | 0
RadixUIAdoptionSection.jsx | 2.52 kB || 21 | 0 || 0 | 0

pdf.mjs | 567.30 kB || 1756 | 284 || 0 | 0

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