Enum mmtk::util::memory::MmapAnnotation

pub enum MmapAnnotation<'a> {
    Space {
        name: &'a str,
    },
    SideMeta {
        space: &'a str,
        meta: &'a str,
    },
    Test {
        file: &'a str,
        line: u32,
    },
    Misc {
        name: &'a str,
    },
}

Annotation for an mmap entry.

Invocations of mmap_fixed and other functions that may transitively call mmap_fixed require an annotation that indicates the purpose of the memory mapping.

This is for debugging. On Linux, mmtk-core will use prctl with PR_SET_VMA to set the human-readable name for the given mmap region. The annotation is ignored on other platforms.

Note that when using Map32 (even when running on 64-bit architectures), the discontiguous memory range is shared between different spaces. Spaces may use mmap to map new chunks, but the same chunk may later be reused by other spaces. The annotation only applies when mmap is called for a chunk for the first time, which reflects which space first attempted the mmap, not which space is currently using the chunk. Use crate::policy::space::print_vm_map to print a more accurate mapping between address ranges and spaces.

On 32-bit architecture, side metadata are allocated in a chunked fasion. One single mmap region will contain many different metadata. In that case, we simply annotate the whole region with a MmapAnnotation::SideMeta where meta is "all".

Variants

Space

Fields

name: &'a str

The name of the space.

The mmap is for a space.

SideMeta

Fields

space: &'a str

The name of the space.

meta: &'a str

The name of the side metadata.

The mmap is for a side metadata.

Test

Fields

file: &'a str

The source file.

line: u32

The line number.

The mmap is for a test case. Usually constructed using the mmap_anno_test! macro.

Misc

Fields

name: &'a str

A human-readable descriptive name.

For all other use cases.

Trait Implementations

impl Display for MmapAnnotation<'_>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.