fix(perf): switch global allocator to jemalloc

Cargo.toml

@@ -66,6 +66,7 @@ libc = "0.2.155"
 libgit2-sys = "0.17.0"
 libloading = "0.8.5"
 memchr = "2.7.4"
+mimalloc = "0.1.43"
 miow = "0.6.0"
 opener = "0.7.1"
 openssl = "=0.10.57" # See rust-lang/cargo#13546 and openssl/openssl#23376 for pinning
@@ -181,6 +182,7 @@ jobserver.workspace = true
 lazycell.workspace = true
 libgit2-sys.workspace = true
 memchr.workspace = true
+mimalloc = { workspace = true, optional = true }
 opener.workspace = true
 os_info.workspace = true
 pasetors.workspace = true
@@ -260,6 +262,8 @@ test = false
 doc = false
 
 [features]
+default = ["mimalloc"]
+mimalloc = ["dep:mimalloc"]
 vendored-openssl = ["openssl/vendored"]
 vendored-libgit2 = ["libgit2-sys/vendored"]
 # This is primarily used by rust-lang/rust distributing cargo the executable.

src/bin/cargo/main.rs

@@ -1,5 +1,9 @@
 #![allow(clippy::self_named_module_files)] // false positive in `commands/build.rs`
 
+#[cfg(feature = "mimalloc")]
+#[global_allocator]
+static GLOBAL: mimalloc::MiMalloc = mimalloc::MiMalloc;
+
 use cargo::core::features;
 use cargo::core::shell::Shell;
 use cargo::util::network::http::http_handle;