rust 不再默认为jemalloc

最新推荐文章于 2025-07-06 14:14:20 发布

转载最新推荐文章于 2025-07-06 14:14:20 发布 · 765 阅读

此前，rustc在部分平台默认将jemalloc内存分配器隐式链接到每个Rust程序。jemalloc性能常优于系统分配器，但会增加可执行文件大小。Rust 1.28稳定了相关属性。PR #55238使jemalloc从Rust标准库移除，明日起Rust程序默认用系统分配器，也可继续用jemalloc。

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摘自 https://www.reddit.com/r/rust/comments/9twam5/jemalloc_was_just_removed_from_the_standard/

jemalloc was just removed from the standard library ?

Until now, rustc implicitly linked the jemalloc memory allocator to every Rust program (not staticlib or cdylib libraries) by default on some platforms (including Linux and macOS). jemalloc is often more performant than the system’s allocator, but not always, and it adds a non-trivial amount to the size of the executable.

In Rust 1.28, we stabilized the #[global_allocator] attribute that allows a program to opt into another memory allocator, and the std::alloc::System type to represent the system’s default allocator.

PR #55238 has landed today, removing jemalloc from the Rust standard library. So starting with tomorrow’s Rust Nightly, Rust programs will use the system allocator by default. You can use the jemallocator crate together with #[global_allocator] if you want to keep using jemalloc.

Changing the default took a long time because it was tricky to figure out a way to do it while still using jemalloc in rustc and LLVM-in-rustc, because of the unusual way rustc is linked. See issues #36963 and #51038 for more background. jemalloc is a significant performance improvement in almost all cases for rustc’s workloads.