Conversation
The default V8 platform pool of 4 worker threads is created during bootstrap. Most processes are I/O bound and never need that parallelism, but still pay for the extra threads and address space. Default the pool to 1. --v8-pool-size=0 still sizes the pool from available parallelism. Assisted-by: Cursor Grok 4.6 Co-authored-by: Yagiz Nizipli <anonrig@users.noreply.github.com>
Collaborator
|
Review requested:
|
nodejs-github-bot
added
c++
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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
The default V8 platform pool of 4 workers is created at bootstrap. Most processes are I/O bound and still pay for those threads and their address space.
Default
--v8-pool-sizeto 1.--v8-pool-size=0still sizes the pool from available parallelism.Benchmarks
Same binary, default (1) vs
--v8-pool-size=4. Snapshot-less local build (--without-intl --without-node-snapshot). Relative comparison.Threads and memory (
/proc/self/status)--v8-pool-size=4node-V8WorkerThread names at default:
node-MainThread, 1×node-V8Worker,DelayedTaskSchedulerWorker,SignalInspector.Startup
Wall clock (n=50, warmup=8):
--v8-pool-size=4node -e ''empty.mjsbenchmark/misc/startup-core.jsn=30mode=process(ops/sec, higher is better):--v8-pool-size=4empty.mjsrequire-builtins.jsStartup is within noise. The win is thread count and virtual address space (about 216 MB less VmSize). Cluster / many Node processes multiply that.
Restore the old default with
--v8-pool-size=4or--v8-pool-size=0.