cgroups_rs/
hugetlb.rs

1// Copyright (c) 2018 Levente Kurusa
2// Copyright (c) 2020 Ant Group
3//
4// SPDX-License-Identifier: Apache-2.0 or MIT
5//
6
7//! This module contains the implementation of the `hugetlb` cgroup subsystem.
8//!
9//! See the Kernel's documentation for more information about this subsystem, found at:
10//!  [Documentation/cgroup-v1/hugetlb.txt](https://www.kernel.org/doc/Documentation/cgroup-v1/hugetlb.txt)
11use log::warn;
12use std::io::Write;
13use std::path::PathBuf;
14
15use crate::error::ErrorKind::*;
16use crate::error::*;
17use crate::{flat_keyed_to_vec, read_u64_from};
18
19use crate::{
20    ControllIdentifier, ControllerInternal, Controllers, HugePageResources, Resources, Subsystem,
21};
22
23/// A controller that allows controlling the `hugetlb` subsystem of a Cgroup.
24///
25/// In essence, using this controller it is possible to limit the use of hugepages in the tasks of
26/// the control group.
27#[derive(Debug, Clone)]
28pub struct HugeTlbController {
29    base: PathBuf,
30    path: PathBuf,
31    sizes: Vec<String>,
32    v2: bool,
33}
34
35impl ControllerInternal for HugeTlbController {
36    fn control_type(&self) -> Controllers {
37        Controllers::HugeTlb
38    }
39    fn get_path(&self) -> &PathBuf {
40        &self.path
41    }
42    fn get_path_mut(&mut self) -> &mut PathBuf {
43        &mut self.path
44    }
45    fn get_base(&self) -> &PathBuf {
46        &self.base
47    }
48
49    fn is_v2(&self) -> bool {
50        self.v2
51    }
52
53    fn apply(&self, res: &Resources) -> Result<()> {
54        // get the resources that apply to this controller
55        let res: &HugePageResources = &res.hugepages;
56
57        for i in &res.limits {
58            let _ = self.set_limit_in_bytes(&i.size, i.limit);
59            if self.limit_in_bytes(&i.size)? != i.limit {
60                return Err(Error::new(Other));
61            }
62        }
63
64        Ok(())
65    }
66}
67
68impl ControllIdentifier for HugeTlbController {
69    fn controller_type() -> Controllers {
70        Controllers::HugeTlb
71    }
72}
73
74impl<'a> From<&'a Subsystem> for &'a HugeTlbController {
75    fn from(sub: &'a Subsystem) -> &'a HugeTlbController {
76        unsafe {
77            match sub {
78                Subsystem::HugeTlb(c) => c,
79                _ => {
80                    assert_eq!(1, 0);
81                    let v = std::mem::MaybeUninit::uninit();
82                    v.assume_init()
83                }
84            }
85        }
86    }
87}
88
89impl HugeTlbController {
90    /// Constructs a new `HugeTlbController` with `root` serving as the root of the control group.
91    pub fn new(root: PathBuf, v2: bool) -> Self {
92        let sizes = get_hugepage_sizes();
93        Self {
94            base: root.clone(),
95            path: root,
96            sizes,
97            v2,
98        }
99    }
100
101    /// Whether the system supports `hugetlb_size` hugepages.
102    pub fn size_supported(&self, hugetlb_size: &str) -> bool {
103        for s in &self.sizes {
104            if s == hugetlb_size {
105                return true;
106            }
107        }
108        false
109    }
110
111    pub fn get_sizes(&self) -> Vec<String> {
112        self.sizes.clone()
113    }
114
115    fn failcnt_v2(&self, hugetlb_size: &str) -> Result<u64> {
116        self.open_path(&format!("hugetlb.{}.events", hugetlb_size), false)
117            .and_then(flat_keyed_to_vec)
118            .and_then(|x| {
119                if x.is_empty() {
120                    return Err(Error::from_string(format!(
121                        "get empty from hugetlb.{}.events",
122                        hugetlb_size
123                    )));
124                }
125                Ok(x[0].1 as u64)
126            })
127    }
128
129    /// Check how many times has the limit of `hugetlb_size` hugepages been hit.
130    pub fn failcnt(&self, hugetlb_size: &str) -> Result<u64> {
131        if self.v2 {
132            return self.failcnt_v2(hugetlb_size);
133        }
134        self.open_path(&format!("hugetlb.{}.failcnt", hugetlb_size), false)
135            .and_then(read_u64_from)
136    }
137
138    /// Get the limit (in bytes) of how much memory can be backed by hugepages of a certain size
139    /// (`hugetlb_size`).
140    pub fn limit_in_bytes(&self, hugetlb_size: &str) -> Result<u64> {
141        let mut file_name = format!("hugetlb.{}.limit_in_bytes", hugetlb_size);
142        if self.v2 {
143            file_name = format!("hugetlb.{}.max", hugetlb_size);
144        }
145        self.open_path(&file_name, false).and_then(read_u64_from)
146    }
147
148    /// Get the current usage of memory that is backed by hugepages of a certain size
149    /// (`hugetlb_size`).
150    pub fn usage_in_bytes(&self, hugetlb_size: &str) -> Result<u64> {
151        let mut file = format!("hugetlb.{}.usage_in_bytes", hugetlb_size);
152        if self.v2 {
153            file = format!("hugetlb.{}.current", hugetlb_size);
154        }
155        self.open_path(&file, false).and_then(read_u64_from)
156    }
157
158    /// Get the maximum observed usage of memory that is backed by hugepages of a certain size
159    /// (`hugetlb_size`).
160    pub fn max_usage_in_bytes(&self, hugetlb_size: &str) -> Result<u64> {
161        self.open_path(
162            &format!("hugetlb.{}.max_usage_in_bytes", hugetlb_size),
163            false,
164        )
165        .and_then(read_u64_from)
166    }
167
168    /// Set the limit (in bytes) of how much memory can be backed by hugepages of a certain size
169    /// (`hugetlb_size`).
170    pub fn set_limit_in_bytes(&self, hugetlb_size: &str, limit: u64) -> Result<()> {
171        let mut file_name = format!("hugetlb.{}.limit_in_bytes", hugetlb_size);
172        if self.v2 {
173            file_name = format!("hugetlb.{}.max", hugetlb_size);
174        }
175        self.open_path(&file_name, true).and_then(|mut file| {
176            file.write_all(limit.to_string().as_ref()).map_err(|e| {
177                Error::with_cause(WriteFailed(file_name.to_string(), limit.to_string()), e)
178            })
179        })
180    }
181}
182
183pub const HUGEPAGESIZE_DIR: &str = "/sys/kernel/mm/hugepages";
184use regex::Regex;
185use std::collections::HashMap;
186use std::fs;
187
188fn get_hugepage_sizes() -> Vec<String> {
189    let dirs = fs::read_dir(HUGEPAGESIZE_DIR);
190    if dirs.is_err() {
191        return Vec::new();
192    }
193
194    dirs.unwrap()
195        .filter_map(|e| {
196            let entry = e.map_err(|e| warn!("readdir error: {:?}", e)).ok()?;
197            let name = entry.file_name().into_string().unwrap();
198            let parts: Vec<&str> = name.split('-').collect();
199            if parts.len() != 2 {
200                return None;
201            }
202            let bmap = get_binary_size_map();
203            let size = parse_size(parts[1], &bmap)
204                .map_err(|e| warn!("parse_size error: {:?}", e))
205                .ok()?;
206            let dabbrs = get_decimal_abbrs();
207
208            Some(custom_size(size as f64, 1024.0, &dabbrs))
209        })
210        .collect()
211}
212
213pub const KB: u128 = 1000;
214pub const MB: u128 = 1000 * KB;
215pub const GB: u128 = 1000 * MB;
216pub const TB: u128 = 1000 * GB;
217pub const PB: u128 = 1000 * TB;
218
219#[allow(non_upper_case_globals)]
220pub const KiB: u128 = 1024;
221#[allow(non_upper_case_globals)]
222pub const MiB: u128 = 1024 * KiB;
223#[allow(non_upper_case_globals)]
224pub const GiB: u128 = 1024 * MiB;
225#[allow(non_upper_case_globals)]
226pub const TiB: u128 = 1024 * GiB;
227#[allow(non_upper_case_globals)]
228pub const PiB: u128 = 1024 * TiB;
229
230pub fn get_binary_size_map() -> HashMap<String, u128> {
231    let mut m = HashMap::new();
232    m.insert("k".to_string(), KiB);
233    m.insert("m".to_string(), MiB);
234    m.insert("g".to_string(), GiB);
235    m.insert("t".to_string(), TiB);
236    m.insert("p".to_string(), PiB);
237    m
238}
239
240pub fn get_decimal_size_map() -> HashMap<String, u128> {
241    let mut m = HashMap::new();
242    m.insert("k".to_string(), KB);
243    m.insert("m".to_string(), MB);
244    m.insert("g".to_string(), GB);
245    m.insert("t".to_string(), TB);
246    m.insert("p".to_string(), PB);
247    m
248}
249
250pub fn get_decimal_abbrs() -> Vec<String> {
251    let m = vec![
252        "B".to_string(),
253        "KB".to_string(),
254        "MB".to_string(),
255        "GB".to_string(),
256        "TB".to_string(),
257        "PB".to_string(),
258        "EB".to_string(),
259        "ZB".to_string(),
260        "YB".to_string(),
261    ];
262    m
263}
264
265fn parse_size(s: &str, m: &HashMap<String, u128>) -> Result<u128> {
266    let re = Regex::new(r"(?P<num>\d+)(?P<mul>[kKmMgGtTpP]?)[bB]?$");
267
268    if re.is_err() {
269        return Err(Error::new(InvalidBytesSize));
270    }
271    let caps = re.unwrap().captures(s).unwrap();
272
273    let num = caps.name("num");
274    let size: u128 = if let Some(num) = num {
275        let n = num.as_str().trim().parse::<u128>();
276        if n.is_err() {
277            return Err(Error::new(InvalidBytesSize));
278        }
279        n.unwrap()
280    } else {
281        return Err(Error::new(InvalidBytesSize));
282    };
283
284    let q = caps.name("mul");
285    let mul: u128 = if let Some(q) = q {
286        let t = m.get(q.as_str());
287        if let Some(t) = t {
288            *t
289        } else {
290            return Err(Error::new(InvalidBytesSize));
291        }
292    } else {
293        return Err(Error::new(InvalidBytesSize));
294    };
295
296    Ok(size * mul)
297}
298
299fn custom_size(mut size: f64, base: f64, m: &[String]) -> String {
300    let mut i = 0;
301    while size >= base && i < m.len() - 1 {
302        size /= base;
303        i += 1;
304    }
305
306    format!("{}{}", size, m[i].as_str())
307}
cgroups_rs/hugetlb.rs

cgroups_rs/
hugetlb.rs
