Use thread::available_parallelism as the default limit for backend parallelism - #160424
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petrochenkov wants to merge 1 commit into
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Use thread::available_parallelism as the default limit for backend parallelism#160424petrochenkov wants to merge 1 commit into
thread::available_parallelism as the default limit for backend parallelism#160424petrochenkov wants to merge 1 commit into
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CC @nnethercote , I remember you mentioning that having a thread per CGU made profiling simpler-ish, or something like that? |
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Makes sense. @bors r+ |
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Use `thread::available_parallelism` as the default limit for backend parallelism Instead of the old scheme with 32-or-unlimited, depending on inherited-ness of the jobserver. Not sure if this needs some wider discussion or not. In the most common case (rustc is called from cargo) nothing changes, because cargo already limits the parallelism to `thread::available_parallelism` by default, and passes this limit to rustc through jobserver. rust-lang#160387 will become simpler if this PR is merged first. r? @bjorn3 @Zoxc
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…uwer Rollup of 21 pull requests Successful merges: - #159844 (Subtree cg_gcc sync (2026-07-24)) - #159326 (Deny multiple EII impls on a single item) - #159535 (Optimize slice::contains for bytewise types) - #159595 (Promote loongarch32-unknown-none* to Tier 2) - #160007 (allow `-Ldependency` search paths for panic runtimes) - #160320 (point at trait definition when it is used as a derive macro) - #160369 (When suggesting method names, prefer *exact* doc aliases over similar names) - #160406 (`DepKind` cleanups) - #160424 (Use `thread::available_parallelism` as the default limit for backend parallelism) - #159014 ([rustdoc] Do not take `doc(cfg())` into account when filtering doctests) - #159303 (Fix ICE for direct inline const generic defaults) - #159977 (Add regression test for bool indexing codegen) - #160165 (reject `...` without pattern post-expansion) - #160295 (Fix rustdoc ICE when checking if a generic arg can be elided) - #160305 (Linkify C-SKY targets in `platform-support.md`) - #160314 (fix borrowck ICE for consts with fn pointer type) - #160322 (ElaborateBoxDeref: remove unnecessary projection) - #160338 (Add regression test for supertrait associated type normalization through dyn) - #160340 (Add regression test for unused_parens on contract clauses) - #160371 (Add doc aliases for transpositions `read_exact_buf` and `read_exact_buf_at`) - #160384 (Add PR body notes for Cargo lock file maintenance)
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Use `thread::available_parallelism` as the default limit for backend parallelism Instead of the old scheme with 32-or-unlimited, depending on inherited-ness of the jobserver. Not sure if this needs some wider discussion or not. In the most common case (rustc is called from cargo) nothing changes, because cargo already limits the parallelism to `thread::available_parallelism` by default, and passes this limit to rustc through jobserver. rust-lang#160387 will become simpler if this PR is merged first. r? @bjorn3 @Zoxc
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Instead of the old scheme with 32-or-unlimited, depending on inherited-ness of the jobserver.
Not sure if this needs some wider discussion or not.
In the most common case (rustc is called from cargo) nothing changes, because cargo already limits the parallelism to
thread::available_parallelismby default, and passes this limit to rustc through jobserver.#160387 will become simpler if this PR is merged first.
r? @bjorn3 @Zoxc