idle_inject_timer_fn(9)

✨ NAME ✨

idle_inject_timer_fn — idle injection timer function. This page is idle_inject_timer_fn(9) from the Kernel API Manual, and it’s lowkey a tiny but important little timer function 🎀.

✨ SYNOPSIS ✨

Bestie, here’s the exact signature — don’t let the enum scare you:

enum hrtimer_restart idle_inject_timer_fn (struct hrtimer *timer );

✨ ARGUMENTS ✨

• timer — the idle injection hrtimer. That’s the timer this function takes, and yes, it’s the whole argument list 💅.

✨ DESCRIPTION ✨

So this function is called when the idle injection timer expires. When it runs, it wakes up the idle injection tasks associated with the timer, and those tasks, in turn, invoke play_idle_precise to inject a specified amount of CPU idle time. That’s the vibe: timer expires, tasks wake up, play_idle_precise does its thing with a specified amount of CPU idle time ✨.

✨ RETURN ✨

It returns HRTIMER_RESTART. Short, sweet, and literally the only return value on the page 🫶.

✨ SEE ALSO ✨

• Kernel file ./drivers/powercap/idle_inject.c — struct idle_inject_thread(9)
• struct idle_inject_device(9)
• idle_inject_wakeup(9)
• idle_inject_fn(9)
• idle_inject_set_duration(9)
• idle_inject_get_duration(9)
• idle_inject_set_latency(9)
• idle_inject_start(9)
• idle_inject_stop(9)
• idle_inject_setup(9)
• idle_inject_should_run(9)
• idle_inject_register_full(9)
• idle_inject_register(9)
• idle_inject_unregister(9)

That’s the whole page, bestie 🫶. Source/version: ./drivers/powercap · Date: October 2026 · Page: idle_inject_timer_fn(9).