Enum ClearRefs

pub enum ClearRefs {
    PGReferencedAll = 1,
    PGReferencedAnonymous = 2,
    PGReferencedFile = 3,
    SoftDirty = 4,
    PeakRSS = 5,
}

Clearing the PG_Referenced and ACCESSED/YOUNG bits provides a method to measure approximately how much memory a process is using. One first inspects the values in the “Referenced” fields for the VMAs shown in /proc/[pid]/smaps to get an idea of the memory footprint of the process. One then clears the PG_Referenced and ACCESSED/YOUNG bits and, after some measured time interval, once again inspects the values in the “Referenced” fields to get an idea of the change in memory footprint of the process during the measured interval. If one is interested only in inspecting the selected mapping types, then the value 2 or 3 can be used instead of 1.

The /proc/[pid]/clear_refs file is present only if the CONFIG_PROC_PAGE_MONITOR kernel configuration option is enabled.

Only writable by the owner of the process

See procfs::Process::clear_refs() and procfs::Process::pagemap()

Variants

PGReferencedAll = 1

(since Linux 2.6.22)

Reset the PG_Referenced and ACCESSED/YOUNG bits for all the pages associated with the process. (Before kernel 2.6.32, writing any nonzero value to this file had this effect.)

PGReferencedAnonymous = 2

(since Linux 2.6.32)

Reset the PG_Referenced and ACCESSED/YOUNG bits for all anonymous pages associated with the process.

PGReferencedFile = 3

(since Linux 2.6.32)

Reset the PG_Referenced and ACCESSED/YOUNG bits for all file-mapped pages associated with the process.

SoftDirty = 4

(since Linux 3.11)

Clear the soft-dirty bit for all the pages associated with the process. This is used (in conjunction with /proc/[pid]/pagemap) by the check- point restore system to discover which pages of a process have been dirtied since the file /proc/[pid]/clear_refs was written to.

PeakRSS = 5

(since Linux 4.0)

Reset the peak resident set size (“high water mark”) to the process’s current resident set size value.

Trait Implementations

impl Clone for ClearRefs

fn clone(&self) -> ClearRefs

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ClearRefs

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

Formats the value using the given formatter.

impl Display for ClearRefs

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

Formats the value using the given formatter.

impl FromStr for ClearRefs

type Err = &'static str

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

impl Hash for ClearRefs

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for ClearRefs

fn eq(&self, other: &ClearRefs) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for ClearRefs

impl Eq for ClearRefs

impl StructuralPartialEq for ClearRefs