Stream: git-wasmtime

Topic: wasmtime / PR #15095 Add configuration for buffer sizes i...

Wasmtime GitHub notifications bot (Oct 30 2026 at 19:50):

alexcrichton opened PR #15095 from alexcrichton:add-a-dknob to bytecodealliance:main:

This commit adds a configuration knob on WasiCtxBuilder to control the default and maximum sizes of buffers used throughout wasmtime-wasi where necessary. These sizes have historically been limited in the past to ensure that guest memory usage is capped but this can cause real-world programs to break such as in WebAssembly/wasi-libc#894 where Python expects a write with a large size to succeed all in one go and doesn't internally have a retry loop for remaining bytes.

The default value of 64KiB is not changed in this commit, but the wasmtime CLI now has a default buffer size of 2MiB to work with more programs by default.

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Wasmtime GitHub notifications bot (Oct 30 2026 at 19:50):

alexcrichton removed the review request for wasmtime-wasi-reviewers from PR #15095.

Wasmtime GitHub notifications bot (Oct 30 2026 at 19:50):

alexcrichton requested rvolosatovs for a review on PR #15095.

Wasmtime GitHub notifications bot (Oct 30 2026 at 19:50):

alexcrichton requested wasmtime-wasi-reviewers for a review on PR #15095.

Wasmtime GitHub notifications bot (Oct 30 2026 at 19:50):

alexcrichton requested fitzgen for a review on PR #15095.

Wasmtime GitHub notifications bot (Oct 30 2026 at 19:50):

alexcrichton removed the review request for wasmtime-core-reviewers from PR #15095.

Wasmtime GitHub notifications bot (Oct 30 2026 at 19:50):

alexcrichton requested wasmtime-core-reviewers for a review on PR #15095.

Wasmtime GitHub notifications bot (Oct 30 2026 at 22:44):

github-actions[bot] added the label wasi on PR #15095.

Last updated: Oct 31 2026 at 23:03 UTC