cgroup: support to set threaded mode in cgroup v2

Support to set threaded mode in cgroup v2. The premise of switching to threaded mode is that only the cgroup of cpuset, cpu and pids is supported.

Fixes: #90

Signed-off-by: yaoyinnan <yaoyinnan@foxmail.com>

tests/builder.rs

@@ -22,7 +22,8 @@ pub fn test_cpu_res_build() {
         .cpu()
         .shares(85)
         .done()
-        .build(h);
+        .build(h)
+        .unwrap();
 
     {
         let cpu: &CpuController = cg.controller_of().unwrap();
@@ -42,7 +43,8 @@ pub fn test_memory_res_build() {
         .swappiness(70)
         .memory_hard_limit(1024 * 1024 * 1024)
         .done()
-        .build(h);
+        .build(h)
+        .unwrap();
 
     {
         let c: &MemController = cg.controller_of().unwrap();
@@ -64,7 +66,8 @@ pub fn test_pid_res_build() {
         .pid()
         .maximum_number_of_processes(MaxValue::Value(123))
         .done()
-        .build(h);
+        .build(h)
+        .unwrap();
 
     {
         let c: &PidController = cg.controller_of().unwrap();
@@ -83,7 +86,8 @@ pub fn test_devices_res_build() {
         .devices()
         .device(1, 6, DeviceType::Char, true, vec![DevicePermissions::Read])
         .done()
-        .build(h);
+        .build(h)
+        .unwrap();
 
     {
         let c: &DevicesController = cg.controller_of().unwrap();
@@ -113,7 +117,8 @@ pub fn test_network_res_build() {
         .network()
         .class_id(1337)
         .done()
-        .build(h);
+        .build(h)
+        .unwrap();
 
     {
         let c: &NetClsController = cg.controller_of().unwrap();
@@ -134,7 +139,8 @@ pub fn test_hugepages_res_build() {
         .hugepages()
         .limit("2MB".to_string(), 4 * 2 * 1024 * 1024)
         .done()
-        .build(h);
+        .build(h)
+        .unwrap();
 
     {
         let c: &HugeTlbController = cg.controller_of().unwrap();
@@ -152,7 +158,8 @@ pub fn test_blkio_res_build() {
         .blkio()
         .weight(100)
         .done()
-        .build(h);
+        .build(h)
+        .unwrap();
 
     {
         let c: &BlkIoController = cg.controller_of().unwrap();

tests/cgroup.rs

@@ -10,28 +10,25 @@ use cgroups_rs::Controller;
 use cgroups_rs::{Cgroup, CgroupPid, Subsystem};
 
 #[test]
-fn test_tasks_iterator() {
+fn test_procs_iterator_cgroup() {
     let h = cgroups_rs::hierarchies::auto();
     let pid = libc::pid_t::from(nix::unistd::getpid()) as u64;
-    let cg = Cgroup::new(h, String::from("test_tasks_iterator"));
+    let cg = Cgroup::new(h, String::from("test_procs_iterator_cgroup")).unwrap();
     {
         // Add a task to the control group.
-        cg.add_task(CgroupPid::from(pid)).unwrap();
+        cg.add_task_by_tgid(CgroupPid::from(pid)).unwrap();
 
-        use std::{thread, time};
-        thread::sleep(time::Duration::from_millis(100));
-
-        let mut tasks = cg.tasks().into_iter();
-        // Verify that the task is indeed in the control group
-        assert_eq!(tasks.next(), Some(CgroupPid::from(pid)));
-        assert_eq!(tasks.next(), None);
+        let mut procs = cg.procs().into_iter();
+        // Verify that the task is indeed in the xcontrol group
+        assert_eq!(procs.next(), Some(CgroupPid::from(pid)));
+        assert_eq!(procs.next(), None);
 
         // Now, try removing it.
-        cg.remove_task(CgroupPid::from(pid));
-        tasks = cg.tasks().into_iter();
+        cg.remove_task_by_tgid(CgroupPid::from(pid)).unwrap();
+        procs = cg.procs().into_iter();
 
         // Verify that it was indeed removed.
-        assert_eq!(tasks.next(), None);
+        assert_eq!(procs.next(), None);
     }
     cg.delete().unwrap();
 }
@@ -83,7 +80,7 @@ fn test_cgroup_v2() {
         return;
     }
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("test_v2"));
+    let cg = Cgroup::new(h, String::from("test_v2")).unwrap();
 
     let mem_controller: &MemController = cg.controller_of().unwrap();
     let (mem, swp, rev) = (4 * 1024 * 1000, 2 * 1024 * 1000, 1024 * 1000);
@@ -103,3 +100,57 @@ fn test_cgroup_v2() {
 
     cg.delete().unwrap();
 }
+
+#[test]
+fn test_tasks_iterator_cgroup_threaded_mode() {
+    if !cgroups_rs::hierarchies::is_cgroup2_unified_mode() {
+        return;
+    }
+    let h = cgroups_rs::hierarchies::auto();
+    let pid = libc::pid_t::from(nix::unistd::getpid()) as u64;
+    let cg = Cgroup::new(h, String::from("test_tasks_iterator_cgroup_threaded_mode")).unwrap();
+    let h = cgroups_rs::hierarchies::auto();
+    let specified_controllers = vec![String::from("cpuset"), String::from("cpu")];
+    let cg_threaded = Cgroup::new_with_specified_controllers(
+        h,
+        String::from("test_tasks_iterator_cgroup_threaded_mode/threaded"),
+        Some(specified_controllers),
+    )
+    .unwrap();
+    cg_threaded.set_cgroup_type("threaded").unwrap();
+    {
+        // Add a task to the control group.
+        cg.add_task_by_tgid(CgroupPid::from(pid)).unwrap();
+
+        let mut procs = cg.procs().into_iter();
+        // Verify that the task is indeed in the xcontrol group
+        assert_eq!(procs.next(), Some(CgroupPid::from(pid)));
+        assert_eq!(procs.next(), None);
+
+        // Add a task to the sub control group.
+        cg_threaded.add_task(CgroupPid::from(pid)).unwrap();
+
+        let mut tasks = cg_threaded.tasks().into_iter();
+        // Verify that the task is indeed in the xcontrol group
+        assert_eq!(tasks.next(), Some(CgroupPid::from(pid)));
+        assert_eq!(tasks.next(), None);
+
+        // Now, try move it to parent.
+        cg_threaded
+            .move_task_to_parent(CgroupPid::from(pid))
+            .unwrap();
+        tasks = cg_threaded.tasks().into_iter();
+
+        // Verify that it was indeed removed.
+        assert_eq!(tasks.next(), None);
+
+        // Now, try removing it.
+        cg.remove_task_by_tgid(CgroupPid::from(pid)).unwrap();
+        procs = cg.procs().into_iter();
+
+        // Verify that it was indeed removed.
+        assert_eq!(procs.next(), None);
+    }
+    cg_threaded.delete().unwrap();
+    cg.delete().unwrap();
+}

tests/cpu.rs

@@ -10,7 +10,7 @@ use cgroups_rs::Cgroup;
 #[test]
 fn test_cfs_quota_and_periods() {
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("test_cfs_quota_and_periods"));
+    let cg = Cgroup::new(h, String::from("test_cfs_quota_and_periods")).unwrap();
 
     let cpu_controller: &CpuController = cg.controller_of().unwrap();
 

tests/cpuset.rs

@@ -13,7 +13,7 @@ use std::fs;
 #[test]
 fn test_cpuset_memory_pressure_root_cg() {
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("test_cpuset_memory_pressure_root_cg"));
+    let cg = Cgroup::new(h, String::from("test_cpuset_memory_pressure_root_cg")).unwrap();
     {
         let cpuset: &CpuSetController = cg.controller_of().unwrap();
 
@@ -27,7 +27,7 @@ fn test_cpuset_memory_pressure_root_cg() {
 #[test]
 fn test_cpuset_set_cpus() {
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("test_cpuset_set_cpus"));
+    let cg = Cgroup::new(h, String::from("test_cpuset_set_cpus")).unwrap();
     {
         let cpuset: &CpuSetController = cg.controller_of().unwrap();
 
@@ -64,7 +64,7 @@ fn test_cpuset_set_cpus() {
 #[test]
 fn test_cpuset_set_cpus_add_task() {
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("test_cpuset_set_cpus_add_task/sub-dir"));
+    let cg = Cgroup::new(h, String::from("test_cpuset_set_cpus_add_task/sub-dir")).unwrap();
 
     let cpuset: &CpuSetController = cg.controller_of().unwrap();
     let set = cpuset.cpuset();
@@ -77,13 +77,13 @@ fn test_cpuset_set_cpus_add_task() {
 
     // Add a task to the control group.
     let pid_i = libc::pid_t::from(nix::unistd::getpid()) as u64;
-    let _ = cg.add_task(CgroupPid::from(pid_i));
+    let _ = cg.add_task_by_tgid(CgroupPid::from(pid_i));
     let tasks = cg.tasks();
     assert!(!tasks.is_empty());
     println!("tasks after added: {:?}", tasks);
 
     // remove task
-    cg.remove_task(CgroupPid::from(pid_i));
+    cg.remove_task_by_tgid(CgroupPid::from(pid_i)).unwrap();
     let tasks = cg.tasks();
     println!("tasks after deleted: {:?}", tasks);
     assert_eq!(0, tasks.len());

tests/devices.rs

@@ -17,7 +17,7 @@ fn test_devices_parsing() {
     }
 
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("test_devices_parsing"));
+    let cg = Cgroup::new(h, String::from("test_devices_parsing")).unwrap();
     {
         let devices: &DevicesController = cg.controller_of().unwrap();
 

tests/hugetlb.rs

@@ -17,7 +17,7 @@ fn test_hugetlb_sizes() {
     }
 
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("test_hugetlb_sizes"));
+    let cg = Cgroup::new(h, String::from("test_hugetlb_sizes")).unwrap();
     {
         let hugetlb_controller: &HugeTlbController = cg.controller_of().unwrap();
         let _ = hugetlb_controller.get_sizes();

tests/memory.rs

@@ -11,7 +11,7 @@ use cgroups_rs::{Cgroup, MaxValue};
 #[test]
 fn test_disable_oom_killer() {
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("test_disable_oom_killer"));
+    let cg = Cgroup::new(h, String::from("test_disable_oom_killer")).unwrap();
     {
         let mem_controller: &MemController = cg.controller_of().unwrap();
 
@@ -40,7 +40,7 @@ fn set_kmem_limit_v1() {
         return;
     }
 
-    let cg = Cgroup::new(h, String::from("set_kmem_limit_v1"));
+    let cg = Cgroup::new(h, String::from("set_kmem_limit_v1")).unwrap();
     {
         let mem_controller: &MemController = cg.controller_of().unwrap();
         mem_controller.set_kmem_limit(1).unwrap();
@@ -55,7 +55,7 @@ fn set_mem_v2() {
         return;
     }
 
-    let cg = Cgroup::new(h, String::from("set_mem_v2"));
+    let cg = Cgroup::new(h, String::from("set_mem_v2")).unwrap();
     {
         let mem_controller: &MemController = cg.controller_of().unwrap();
 

tests/pids.rs

@@ -17,7 +17,7 @@ use libc::pid_t;
 #[test]
 fn create_and_delete_cgroup() {
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("create_and_delete_cgroup"));
+    let cg = Cgroup::new(h, String::from("create_and_delete_cgroup")).unwrap();
     {
         let pidcontroller: &PidController = cg.controller_of().unwrap();
         pidcontroller.set_pid_max(MaxValue::Value(1337)).unwrap();
@@ -31,7 +31,7 @@ fn create_and_delete_cgroup() {
 #[test]
 fn test_pids_current_is_zero() {
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("test_pids_current_is_zero"));
+    let cg = Cgroup::new(h, String::from("test_pids_current_is_zero")).unwrap();
     {
         let pidcontroller: &PidController = cg.controller_of().unwrap();
         let current = pidcontroller.get_pid_current();
@@ -43,7 +43,7 @@ fn test_pids_current_is_zero() {
 #[test]
 fn test_pids_events_is_zero() {
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("test_pids_events_is_zero"));
+    let cg = Cgroup::new(h, String::from("test_pids_events_is_zero")).unwrap();
     {
         let pidcontroller: &PidController = cg.controller_of().unwrap();
         let events = pidcontroller.get_pid_events();
@@ -56,7 +56,7 @@ fn test_pids_events_is_zero() {
 #[test]
 fn test_pid_events_is_not_zero() {
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("test_pid_events_is_not_zero"));
+    let cg = Cgroup::new(h, String::from("test_pid_events_is_not_zero")).unwrap();
     {
         let pids: &PidController = cg.controller_of().unwrap();
         let before = pids.get_pid_events();
@@ -65,7 +65,7 @@ fn test_pid_events_is_not_zero() {
         match unsafe { fork() } {
             Ok(ForkResult::Parent { child, .. }) => {
                 // move the process into the control group
-                let _ = pids.add_task(&(pid_t::from(child) as u64).into());
+                let _ = pids.add_task_by_tgid(&(pid_t::from(child) as u64).into());
 
                 println!("added task to cg: {:?}", child);
 

tests/resources.rs

@@ -11,7 +11,7 @@ use cgroups_rs::{Cgroup, MaxValue, PidResources, Resources};
 #[test]
 fn pid_resources() {
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("pid_resources"));
+    let cg = Cgroup::new(h, String::from("pid_resources")).unwrap();
     {
         let res = Resources {
             pid: PidResources {