sched.go RawHistoryFolder

1// Package sched configures latency-sensitive compositor threads.
2package sched
3
4import (
5	"errors"
6	"sync"
7
8	"github.com/bnema/zerowrap"
9	"golang.org/x/sys/unix"
10)
11
12var unavailable sync.Once
13
14// Realtime sets SCHED_RR at its minimum priority on the calling locked OS thread.
15// Children cannot inherit this scheduling policy.
16func Realtime(log zerowrap.Logger) error {
17	err := unix.SchedSetAttr(0, &unix.SchedAttr{
18		Size: unix.SizeofSchedAttr, Policy: unix.SCHED_RR,
19		Flags: unix.SCHED_FLAG_RESET_ON_FORK, Priority: 1,
20	}, 0)
21	if errors.Is(err, unix.EPERM) {
22		unavailable.Do(func() {
23			log.Info().Msg("realtime scheduling unavailable, grant CAP_SYS_NICE")
24		})
25		return nil
26	}
27	return err
28}