It's only for Rust binaries that are built with the the -linux-musl* (instead -linux-gnu*) toolchains, which are not the default, and usually used to make portable/static binaries.
It's only for Rust binaries that are built with the the -linux-musl* (instead -linux-gnu*) toolchains, which are not the default, and usually used to make portable/static binaries.
Unless you're on a distro like Alpine where musl is the system libc. Which is common in, e.g., containers.
It's still possible to build Rust binaries with jemalloc if you need the performance (or another allocator). Also, it will heavily depend on the usecase; for many usecases, Rust will in fact pressure the heap less, precisely because it tracks ownership, and passing or returning structs by value (on the stack) is often "free" if you pass the ownership as well.