clocksource...spend_timing(9)

💅 clocksource_stop_suspend_timing — clocksource...spend_timing(9) 💅

okay so we're in the Kernel API Manual, bestie, and this page is the main character: clocksource...spend_timing(9). No cap. 💖

🎀 NAME 🎀

clocksource_stop_suspend_timing — Stop measuring the suspend timing. That's the whole vibe. ✨

🌸 SYNOPSIS 🌸

u64 clocksource_stop_suspend_timing (struct clocksource *cs , u64
cycle_now );

🦋 ARGUMENTS 🦋

• cs — current clocksource from timekeeping. 💫
• cycle_now — current cycles from timekeeping. ⏱️

✨ DESCRIPTION ✨

So this function will calculate the suspend time from suspend timer. That's it, that's the job. 💅

Returns nanoseconds since suspend started, and 0 if there's no usable suspend clocksource. periodt.

It's called early in the resume process from timekeeping_resume — and when I say early, I mean only one cpu, no processes are running, and the interrupts are disabled. 😭 So yeah, it is therefore possible to stop the suspend timer without taking the clocksource mutex. The mutex can stay unbothered, iykyk. 🫶

🌈 SEE ALSO 🌈

Kernel file ./kernel/time/clocksource.c and the whole function friend group:

• clocks_calc_mult_shift(9)
• clocksource_mark_unstable(9)
• clocksource_suspend_select(9)
• clocksource_start_suspend_timing(9)
• clocksource_suspend(9)
• clocksource_resume(9)
• clocksource_touch_watchdog(9)
• clocksource_max_adjustment(9)
• clocks_calc_max_nsecs(9)
• clocksource_update_max_deferment(9)
• clocksource_select(9)
• __clocksource_update_freq_scale(9)
• __clocksource_register_scale(9)
• clocksource_unregister(9)
• current_clocksource_show(9)
• current_clocksource_store(9)
• unbind_clocksource_store(9)
• available_clocksource_show(9)
• boot_override_clocksource(9)
• boot_override_clock(9)

and that's the page, bestie! 💖 This one's from ./kernel/time, dated October 2026, and it's the clocksource...spend_timing(9) page. Slay and goodbye! 🎀