mmtk/util/os/imp/unix_like/linux_like/
linux_common.rs

1use crate::util::address::Address;
2use crate::util::os::imp::unix_like::unix_common;
3use crate::util::os::*;
4use libc::{cpu_set_t, sched_getaffinity, sched_setaffinity, CPU_COUNT, CPU_SET, CPU_ZERO};
5use std::io::Result;
6
7pub fn set_vma_name(start: Address, size: usize, annotation: &MmapAnnotation) {
8    // `PR_SET_VMA` is new in Linux 5.17.  We compile against a version of the `libc` crate that
9    // has the `PR_SET_VMA_ANON_NAME` constant.  When runnning on an older kernel, it will not
10    // recognize this attribute and will return `EINVAL`.  However, `prctl` may return `EINVAL`
11    // for other reasons, too.  That includes `start` being an invalid address, and the
12    // formatted `anno_cstr` being longer than 80 bytes including the trailing `'\0'`.  But
13    // since this prctl is used for debugging, we log the error instead of panicking.
14    let anno_str = annotation.to_string();
15    let anno_cstr = std::ffi::CString::new(anno_str).unwrap();
16    let result = unix_common::wrap_libc_call(
17        &|| unsafe {
18            libc::prctl(
19                libc::PR_SET_VMA,
20                libc::PR_SET_VMA_ANON_NAME,
21                start.to_ptr::<libc::c_void>(),
22                size,
23                anno_cstr.as_ptr(),
24            )
25        },
26        0,
27    );
28    if let Err(e) = result {
29        debug!("Error while calling prctl: {e}");
30    }
31}
32
33/// Set huge page option for the given memory.
34pub fn set_hugepage(start: Address, size: usize, options: HugePageSupport) -> Result<()> {
35    match options {
36        HugePageSupport::No => Ok(()),
37        HugePageSupport::TransparentHugePages => unix_common::wrap_libc_call(
38            &|| unsafe { libc::madvise(start.to_mut_ptr(), size, libc::MADV_HUGEPAGE) },
39            0,
40        ),
41    }
42}
43
44impl MmapStrategy {
45    /// get the flags for POSIX mmap.
46    pub fn get_posix_mmap_flags(&self) -> i32 {
47        let mut flags = libc::MAP_PRIVATE | libc::MAP_ANONYMOUS;
48        if self.replace {
49            flags |= libc::MAP_FIXED;
50        } else {
51            flags |= libc::MAP_FIXED_NOREPLACE
52        }
53        if !self.reserve {
54            flags |= libc::MAP_NORESERVE;
55        }
56        flags
57    }
58}
59
60/// Get the memory maps for the process. The returned string is a multi-line string.
61/// This is only meant to be used for debugging. For example, log process memory maps after detecting a clash.
62pub fn get_process_memory_maps() -> Result<String> {
63    // print map
64    use std::fs::File;
65    use std::io::Read;
66    let mut data = String::new();
67    let mut f = File::open("/proc/self/maps")?;
68    f.read_to_string(&mut data)?;
69    Ok(data)
70}
71
72pub fn get_total_num_cpus() -> CoreNum {
73    use std::mem::MaybeUninit;
74    unsafe {
75        let mut cs = MaybeUninit::zeroed().assume_init();
76        CPU_ZERO(&mut cs);
77        sched_getaffinity(0, std::mem::size_of::<cpu_set_t>(), &mut cs);
78        CPU_COUNT(&cs) as u16
79    }
80}
81
82pub fn bind_current_thread_to_core(core_id: CoreId) {
83    use std::mem::MaybeUninit;
84    unsafe {
85        let mut cs = MaybeUninit::zeroed().assume_init();
86        CPU_ZERO(&mut cs);
87        CPU_SET(core_id as usize, &mut cs);
88        sched_setaffinity(0, std::mem::size_of::<cpu_set_t>(), &cs);
89    }
90}
91
92pub fn bind_current_thread_to_cpuset(cpuset: &[CoreId]) {
93    use std::mem::MaybeUninit;
94    unsafe {
95        let mut cs = MaybeUninit::zeroed().assume_init();
96        CPU_ZERO(&mut cs);
97        for cpu in cpuset {
98            CPU_SET(*cpu as usize, &mut cs);
99        }
100        sched_setaffinity(0, std::mem::size_of::<cpu_set_t>(), &cs);
101    }
102}
103
104pub fn dzmmap(
105    start: Address,
106    size: usize,
107    strategy: MmapStrategy,
108    annotation: &MmapAnnotation<'_>,
109) -> MmapResult<Address> {
110    let addr = unix_common::mmap(start, size, strategy, annotation)?;
111
112    if !cfg!(feature = "no_mmap_annotation") {
113        set_vma_name(addr, size, annotation);
114    }
115
116    set_hugepage(addr, size, strategy.huge_page).expect("Failed to set huge page option");
117
118    // We do not need to explicitly zero for Linux (memory is guaranteed to be zeroed)
119
120    Ok(addr)
121}
122
123pub fn panic_if_unmapped(start: Address, size: usize) {
124    let strategy = MmapStrategy {
125        huge_page: HugePageSupport::No,
126        prot: MmapProtection::ReadWrite,
127        replace: false,
128        reserve: true,
129    };
130    let annotation = MmapAnnotation::Misc {
131        name: "panic_if_unmapped",
132    };
133    match unix_common::mmap(start, size, strategy, &annotation) {
134        Ok(_) => panic!("{} of size {} is not mapped", start, size),
135        Err(e) => {
136            assert!(
137                e.error.kind() == std::io::ErrorKind::AlreadyExists,
138                "Failed to check mapped: {:?}",
139                e
140            );
141        }
142    }
143}
mmtk/util/os/imp/unix_like/linux_like/linux_common.rs

mmtk/util/os/imp/unix_like/linux_like/
linux_common.rs
