feat: add cpu isolation for system, perf and benchmark

Author: not-matthias

Cargo.lock

@@ -54,6 +54,7 @@ debugid = "0.8.0"
 memmap2 = "0.9.5"
 nix = { version = "0.29.0", features = ["fs"] }
 futures = "0.3.31"
+num_cpus = "1.17.0"
 
 [target.'cfg(target_os = "linux")'.dependencies]
 procfs = "0.17.0"

Cargo.toml

@@ -0,0 +1,63 @@
+use super::setup::run_with_sudo;
+
+pub struct CpuIsolation {
+    nproc: u32,
+}
+
+impl CpuIsolation {
+    pub fn new() -> Self {
+        Self {
+            nproc: num_cpus::get() as u32,
+        }
+    }
+
+    pub fn nproc(&self) -> u32 {
+        self.nproc
+    }
+
+    fn set_allowed_cpus(scope: &str, allowed_cpus: &[u32]) -> anyhow::Result<()> {
+        let cpus = allowed_cpus
+            .iter()
+            .map(|cpu| cpu.to_string())
+            .collect::<Vec<_>>()
+            .join(",");
+
+        run_with_sudo(&[
+            "systemctl",
+            "set-property",
+            scope,
+            &format!("AllowedCPUs={}", cpus),
+        ])?;
+
+        Ok(())
+    }
+
+    pub fn isolate_system(&self, allowed_cpus: &[u32]) -> anyhow::Result<()> {
+        Self::set_allowed_cpus("system.slice", allowed_cpus)?;
+        Self::set_allowed_cpus("init.scope", allowed_cpus)?;
+
+        Ok(())
+    }
+
+    pub fn isolate_user(&self, allowed_cpus: &[u32]) -> anyhow::Result<()> {
+        Self::set_allowed_cpus("user.slice", allowed_cpus)?;
+
+        Ok(())
+    }
+
+    pub fn reset_isolation(nproc: u32) -> anyhow::Result<()> {
+        let allowed_cpus = (0..nproc).collect::<Vec<_>>();
+        Self::set_allowed_cpus("system.slice", &allowed_cpus)?;
+        Self::set_allowed_cpus("user.slice", &allowed_cpus)?;
+        Self::set_allowed_cpus("init.scope", &allowed_cpus)?;
+
+        Ok(())
+    }
+}
+
+impl Drop for CpuIsolation {
+    fn drop(&mut self) {
+        Self::reset_isolation(self.nproc)
+            .unwrap_or_else(|e| eprintln!("Failed to reset CPU isolation: {}", e));
+    }
+}

src/run/runner/helpers/isolation.rs

@@ -1,5 +1,6 @@
 pub mod env;
 pub mod get_bench_command;
+pub mod isolation;
 pub mod profile_folder;
 pub mod run_command_with_log_pipe;
 pub mod setup;

src/run/runner/helpers/mod.rs

@@ -1,6 +1,7 @@
 #![cfg_attr(not(unix), allow(dead_code, unused_mut))]
 
 use crate::prelude::*;
+use crate::run::runner::helpers::isolation::CpuIsolation;
 use crate::run::runner::helpers::run_command_with_log_pipe::run_command_with_log_pipe_and_callback;
 use crate::run::runner::helpers::setup::run_with_sudo;
 use crate::run::runner::valgrind::helpers::ignored_objects_path::get_objects_path_to_ignore;
@@ -96,10 +97,21 @@ impl PerfRunner {
         };
         debug!("Using call graph mode: {}", cg_mode);
 
+        const PERF_CPU: u32 = 2;
+        const BENCH_CPU: u32 = 3;
+        const BENCH_CPUS: [u32; 2] = [PERF_CPU, BENCH_CPU];
+        const HOST_CPUS: [u32; 2] = [0, 1];
+
+        let cpu_isolation = CpuIsolation::new();
+        assert!(cpu_isolation.nproc() >= 4);
+        cpu_isolation.isolate_system(&HOST_CPUS)?;
+        cpu_isolation.isolate_user(&BENCH_CPUS)?;
+
         cmd.args([
             "-c",
             &format!(
-                "perf record --user-callchains --freq=999 --switch-output --control=fifo:{},{} --delay=-1 -g --call-graph={cg_mode} --output={} -- {bench_cmd}",
+                "taskset -c {PERF_CPU} perf record --user-callchains --freq=999 --switch-output --control=fifo:{},{} --delay=-1 -g --call-graph={cg_mode} --output={} -- \
+                taskset -c {BENCH_CPU} {bench_cmd}",
                 perf_fifo.ctl_fifo_path.to_string_lossy(),
                 perf_fifo.ack_fifo_path.to_string_lossy(),
                 perf_file.path().to_string_lossy()