Struct ScanOptions 

pub struct ScanOptions {
    pub threads: bool,
    pub smaps: bool,
    pub gpu: bool,
    pub delayacct: bool,
}

What the front end is currently showing, and therefore what the sampler has to pay for.

Why this is one struct rather than three setters

The per-process reads named here are not free:

• threads — an extra stat read per thread (~1700 per tick on a desktop).
• smaps — a kernel walk over every VMA of every process (tens of ms).
• gpu — a readdir of fdinfo plus a read per open DRM fd, per process.

Each one used to be its own set_* method on the trait. That worked until the third, at which point a front end had to remember to call every setter on every change, and a forgotten one meant either a wasted scan or a column of dashes. Passing the whole decision as one value makes both failures impossible: there is one call, it carries everything, and a new gated read can only be added by extending this struct — which breaks every call site until it is answered.

Fields

threads: bool

Emit one row per thread as well as one per process.

smaps: bool

Read /proc/<pid>/smaps_rollup (PSS, EPSS, private, per-process swap).

gpu: bool

Read /proc/<pid>/fdinfo for drm-* keys (GPU time and percentage).

delayacct: bool

Read per-task delay counters over TASKSTATS generic netlink.

Implementations

impl ScanOptions

pub const fn none() -> Self

Everything off: the cheap scan, which is what the shipped default column set and the default header need.

pub const fn with_threads(self, on: bool) -> Self

pub const fn with_smaps(self, on: bool) -> Self

pub const fn with_gpu(self, on: bool) -> Self

pub const fn with_delayacct(self, on: bool) -> Self

Trait Implementations

impl Clone for ScanOptions

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ScanOptions

impl Debug for ScanOptions

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

Formats the value using the given formatter.

impl Default for ScanOptions

fn default() -> Self

Returns the “default value” for a type.

impl Eq for ScanOptions

impl PartialEq for ScanOptions

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for ScanOptions