scx_rustlite: simple vtime-based scheduler written in Rust

scheds/rust/meson.build

@@ -1,2 +1,3 @@
 subdir('scx_layered')
 subdir('scx_rusty')
+subdir('scx_rustlite')

scheds/rust/scx_rustlite/.gitignore

@@ -0,0 +1,3 @@
+src/bpf/.output
+Cargo.lock
+target

scheds/rust/scx_rustlite/Cargo.toml

@@ -0,0 +1,27 @@
+[package]
+name = "scx_rustlite"
+version = "0.0.1"
+authors = ["Andrea Righi <[email protected]>", "Canonical"]
+edition = "2021"
+description = "Userspace scheduling with BPF"
+license = "GPL-2.0-only"
+
+[dependencies]
+anyhow = "1.0.65"
+bitvec = { version = "1.0", features = ["serde"] }
+clap = { version = "4.1", features = ["derive", "env", "unicode", "wrap_help"] }
+ctrlc = { version = "3.1", features = ["termination"] }
+fb_procfs = "0.7.0"
+hex = "0.4.3"
+libbpf-rs = "0.22.0"
+libc = "0.2.137"
+log = "0.4.17"
+ordered-float = "3.4.0"
+scx_utils = { path = "../../../rust/scx_utils", version = "0.4" }
+simplelog = "0.12.0"
+
+[build-dependencies]
+scx_utils = { path = "../../../rust/scx_utils", version = "0.4" }
+
+[features]
+enable_backtrace = []

scheds/rust/scx_rustlite/LICENSE

@@ -0,0 +1 @@
+../../../LICENSE

scheds/rust/scx_rustlite/build.rs

@@ -0,0 +1,11 @@
+// This software may be used and distributed according to the terms of the
+// GNU General Public License version 2.
+
+fn main() {
+    scx_utils::BpfBuilder::new()
+        .unwrap()
+        .enable_intf("src/bpf/intf.h", "bpf_intf.rs")
+        .enable_skel("src/bpf/main.bpf.c", "bpf")
+        .build()
+        .unwrap();
+}

scheds/rust/scx_rustlite/meson.build

@@ -0,0 +1,7 @@
+custom_target('scx_rustlite',
+              output: '@PLAINNAME@.__PHONY__',
+              input: 'Cargo.toml',
+              command: [cargo, 'build', '--manifest-path=@INPUT@', '--target-dir=@OUTDIR@',
+                        cargo_build_args],
+              env: cargo_env,
+              build_by_default: true)

scheds/rust/scx_rustlite/rustfmt.toml

@@ -0,0 +1,8 @@
+# Get help on options with `rustfmt --help=config`
+# Please keep these in alphabetical order.
+edition = "2021"
+group_imports = "StdExternalCrate"
+imports_granularity = "Item"
+merge_derives = false
+use_field_init_shorthand = true
+version = "Two"

scheds/rust/scx_rustlite/src/bpf/intf.h

@@ -0,0 +1,55 @@
+// This software may be used and distributed according to the terms of the
+// GNU General Public License version 2.
+
+#ifndef __INTF_H
+#define __INTF_H
+
+#define MAX(x, y) ((x) > (y) ? (x) : (y))
+#define MIN(x, y) ((x) < (y) ? (x) : (y))
+
+#define NSEC_PER_SEC	1000000000L
+#define CLOCK_BOOTTIME	7
+
+#include <stdbool.h>
+#ifndef __kptr
+#ifdef __KERNEL__
+#error "__kptr_ref not defined in the kernel"
+#endif
+#define __kptr
+#endif
+
+#ifndef __KERNEL__
+typedef unsigned char u8;
+typedef unsigned int u32;
+typedef int s32;
+typedef unsigned long long u64;
+typedef long long s64;
+#endif
+
+/*
+ * Task sent to the user-space scheduler by the BPF dispatcher.
+ *
+ * All attributes are collected from the kernel by the the BPF component.
+ */
+struct queued_task_ctx {
+	s32 pid;
+	u64 sum_exec_runtime; /* Total cpu time */
+	u64 weight; /* Task static priority */
+};
+
+/*
+ * Task sent to the BPF dispatcher by the user-space scheduler.
+ *
+ * This structure has a payload that can be used by the user-space scheduler to
+ * send debugging information to the BPF dispatcher (i.e., vruntime, etc.),
+ * depending on the particular scheduler implementation.
+ *
+ * This struct can be easily extended to send more information to the
+ * dispatcher (i.e., a target CPU, a variable time slice, etc.).
+ */
+struct dispatched_task_ctx {
+	s32 pid;
+	u64 payload; /* Task payload */
+};
+
+#endif /* __INTF_H */