cgroups_rs/fs/
cpuacct.rs

1// Copyright (c) 2018 Levente Kurusa
2//
3// SPDX-License-Identifier: Apache-2.0 or MIT
4//
5
6//! This module contains the implementation of the `cpuacct` cgroup subsystem.
7//!
8//! See the Kernel's documentation for more information about this subsystem, found at:
9//!  [Documentation/cgroup-v1/cpuacct.txt](https://www.kernel.org/doc/Documentation/cgroup-v1/cpuacct.txt)
10use std::io::Write;
11use std::path::PathBuf;
12
13use crate::fs::error::ErrorKind::*;
14use crate::fs::error::*;
15
16use crate::fs::{read_string_from, read_u64_from};
17use crate::fs::{ControllIdentifier, ControllerInternal, Controllers, Resources, Subsystem};
18
19/// A controller that allows controlling the `cpuacct` subsystem of a Cgroup.
20///
21/// In essence, this control group provides accounting (hence the name `cpuacct`) for CPU usage of
22/// the tasks in the control group.
23#[derive(Debug, Clone)]
24pub struct CpuAcctController {
25    base: PathBuf,
26    path: PathBuf,
27}
28
29/// Represents the statistics retrieved from the control group.
30#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
31pub struct CpuAcct {
32    /// Divides the time used by the tasks into `user` time and `system` time.
33    pub stat: String,
34    /// Total CPU time (in nanoseconds) spent by the tasks.
35    pub usage: u64,
36    /// Total CPU time (in nanoseconds) spent by the tasks, broken down by CPU and by whether the
37    /// time spent is `user` time or `system` time.
38    ///
39    /// An example is as follows:
40    /// ```text
41    /// cpu user system
42    /// 0 8348363768 0
43    /// 1 8324369100 0
44    /// 2 8598185449 0
45    /// 3 8648262473 0
46    /// ```
47    pub usage_all: String,
48    /// CPU time (in nanoseconds) spent by the tasks, broken down by each CPU.
49    /// Times spent in each CPU are separated by a space.
50    pub usage_percpu: String,
51    /// As for `usage_percpu`, but the `system` time spent.
52    pub usage_percpu_sys: String,
53    /// As for `usage_percpu`, but the `user` time spent.
54    pub usage_percpu_user: String,
55    /// CPU time (in nanoseconds) spent by the tasks that counted for `system` time.
56    pub usage_sys: u64,
57    /// CPU time (in nanoseconds) spent by the tasks that counted for `user` time.
58    pub usage_user: u64,
59}
60
61impl ControllerInternal for CpuAcctController {
62    fn control_type(&self) -> Controllers {
63        Controllers::CpuAcct
64    }
65    fn get_path(&self) -> &PathBuf {
66        &self.path
67    }
68    fn get_path_mut(&mut self) -> &mut PathBuf {
69        &mut self.path
70    }
71    fn get_base(&self) -> &PathBuf {
72        &self.base
73    }
74
75    fn apply(&self, _res: &Resources) -> Result<()> {
76        Ok(())
77    }
78}
79
80impl ControllIdentifier for CpuAcctController {
81    fn controller_type() -> Controllers {
82        Controllers::CpuAcct
83    }
84}
85
86impl<'a> From<&'a Subsystem> for &'a CpuAcctController {
87    fn from(sub: &'a Subsystem) -> &'a CpuAcctController {
88        unsafe {
89            match sub {
90                Subsystem::CpuAcct(c) => c,
91                _ => {
92                    assert_eq!(1, 0);
93                    let v = std::mem::MaybeUninit::uninit();
94                    v.assume_init()
95                }
96            }
97        }
98    }
99}
100
101impl CpuAcctController {
102    /// Contructs a new `CpuAcctController` with `root` serving as the root of the control group.
103    pub fn new(point: PathBuf, root: PathBuf) -> Self {
104        Self {
105            base: root,
106            path: point,
107        }
108    }
109
110    /// Gathers the statistics that are available in the control group into a `CpuAcct` structure.
111    pub fn cpuacct(&self) -> CpuAcct {
112        CpuAcct {
113            stat: self
114                .open_path("cpuacct.stat", false)
115                .and_then(read_string_from)
116                .unwrap_or_default(),
117            usage: self
118                .open_path("cpuacct.usage", false)
119                .and_then(read_u64_from)
120                .unwrap_or(0),
121            usage_all: self
122                .open_path("cpuacct.usage_all", false)
123                .and_then(read_string_from)
124                .unwrap_or_default(),
125            usage_percpu: self
126                .open_path("cpuacct.usage_percpu", false)
127                .and_then(read_string_from)
128                .unwrap_or_default(),
129            usage_percpu_sys: self
130                .open_path("cpuacct.usage_percpu_sys", false)
131                .and_then(read_string_from)
132                .unwrap_or_default(),
133            usage_percpu_user: self
134                .open_path("cpuacct.usage_percpu_user", false)
135                .and_then(read_string_from)
136                .unwrap_or_default(),
137            usage_sys: self
138                .open_path("cpuacct.usage_sys", false)
139                .and_then(read_u64_from)
140                .unwrap_or(0),
141            usage_user: self
142                .open_path("cpuacct.usage_user", false)
143                .and_then(read_u64_from)
144                .unwrap_or(0),
145        }
146    }
147
148    /// Reset the statistics the kernel has gathered about the control group.
149    pub fn reset(&self) -> Result<()> {
150        self.open_path("cpuacct.usage", true).and_then(|mut file| {
151            file.write_all(b"0").map_err(|e| {
152                Error::with_cause(WriteFailed("cpuacct.usage".to_string(), "0".to_string()), e)
153            })
154        })
155    }
156}
cgroups_rs/fs/cpuacct.rs

cgroups_rs/fs/
cpuacct.rs
