A batch ran its photos strictly one after another: each render is
row-parallel inside, but a photo's decode, its PNG/TIFF/WebP encode and
the wait on a GPU render are mostly serial, so a 32-core machine averaged
~9.5 busy cores on the CPU path and 1-2 with the GPU.
run_batch now keeps export_parallelism() photos in flight (cores / 4,
1..=4; one on wasm32) on scoped lane threads plus the calling thread.
Each holds an estimate of its working memory from a new export_gate
(twice the memory budget, separate from the decode gate it nests over),
so full-size 24 MP exports (~1.2 GB each) run two at a time by default.
Lanes run at most `lanes` photos past the last one placed, which also
bounds the finished files waiting for their turn. Paths, conflict
handling, original protection, writes, results and progress stay in
batch order (Placer), so the files are the same as one at a time; a
panic in a lane becomes that photo's error.
render_bench's batch scenario now goes through export_batch. 8 x 24 MP
JPEGs, 32 cores + RTX 4080 Laptop: CPU 3.87 s -> 2.35 s, GPU 4.21 s ->
1.82 s.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
- memory::budget (default min(25% RAM, 1.5 GiB); LIGHTCRAFT_MEMORY_MB, app.memoryBudget):
half for engine caches (sources + rendered previews, LRU across them via a global
use tick; the photo on screen stays), a quarter for decodes in flight (WorkGate:
thumbnails, prefetch and import probes wait; loupe/export loads never wait), an
eighth for the GPU free pool.
- GPU: best-fit buffer reuse (<= 25% slack), buffers released outside a render are
pooled at once (no stranded retired lists), pool trimmed after 3 s idle.
- Decodes drop file bytes and raw samples early, colour/crop/orient in place.
- macOS: apps install malloc_zone_pressure_relief as the release hook (after each
decode, import and idle trim): freed large blocks no longer stay resident.
14 raws + loupe + 12 steps (M4 Pro): peak RSS 1.9-2.3 GB -> 0.83-0.99 GB, footprint
2.5-2.6 GB -> 0.91-0.96 GB, heap peak 930 -> 656 MB; stepping median ~13 ms.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Michael Anderson