Use mimalloc when targeting musl

Also removes the armv7 linux build.
If you used it, let me know!

.github/workflows/build.yaml

@@ -106,11 +106,6 @@ jobs:
             name: linux-aarch64
             build: zigbuild
             features: nightly
-          - platform: ubuntu-latest
-            target: armv7-unknown-linux-musleabi
-            name: linux-armv7l
-            build: zigbuild
-            features: default
           - platform: windows-latest
             target: i686-pc-windows-msvc
             name: windows-x86

Cargo.lock

@@ -376,6 +376,16 @@ dependencies = [
  "pkg-config",
 ]
 
+[[package]]
+name = "libmimalloc-sys"
+version = "0.1.39"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "23aa6811d3bd4deb8a84dde645f943476d13b248d818edcf8ce0b2f37f036b44"
+dependencies = [
+ "cc",
+ "libc",
+]
+
 [[package]]
 name = "log"
 version = "0.4.22"
@@ -417,6 +427,15 @@ version = "2.7.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "78ca9ab1a0babb1e7d5695e3530886289c18cf2f87ec19a575a0abdce112e3a3"
 
+[[package]]
+name = "mimalloc"
+version = "0.1.43"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "68914350ae34959d83f732418d51e2427a794055d0b9529f48259ac07af65633"
+dependencies = [
+ "libmimalloc-sys",
+]
+
 [[package]]
 name = "miniz_oxide"
 version = "0.8.0"
@@ -463,6 +482,7 @@ dependencies = [
  "itertools",
  "log",
  "md-5",
+ "mimalloc",
  "nod",
  "quick-xml",
  "serde",

nodtool/Cargo.toml

@@ -43,6 +43,9 @@ xxhash-rust = { version = "0.8", features = ["xxh64"] }
 zerocopy = { version = "0.7", features = ["alloc", "derive"] }
 zstd = "0.13"
 
+[target.'cfg(target_env = "musl")'.dependencies]
+mimalloc = "0.1"
+
 [build-dependencies]
 hex = { version = "0.4", features = ["serde"] }
 quick-xml = { version = "0.36", features = ["serialize"] }

nodtool/src/main.rs

@@ -1,5 +1,11 @@
 mod argp_version;
 
+// musl's allocator is very slow, so use mimalloc when targeting musl.
+// Otherwise, use the system allocator to avoid extra code size.
+#[cfg(target_env = "musl")]
+#[global_allocator]
+static ALLOC: mimalloc::MiMalloc = mimalloc::MiMalloc;
+
 use std::{env, error::Error, ffi::OsStr, fmt, path::PathBuf, str::FromStr};
 
 use argp::{FromArgValue, FromArgs};