tmigr_quick_check(9)

Hey bestie 💖 welcome to tmigr_quick_check(9), straight out of the Kernel API Manual. It’s giving “Quick forecast of next tmigr event when CPU wants to go idle,” and we’re gonna get into it. 🫶✨

🌸 NAME 🌸

tmigr_quick_check — Quick forecast of next tmigr event when CPU wants to go idle. 💅

✨ SYNOPSIS ✨

u64 tmigr_quick_check (u64 nextevt );

🎀 ARGUMENTS 🎀

• nextevt — The next global timer expiry of the current CPU.

🔥 RETURN 🔥

Okay so this function can hand you back three possible outcomes, and the conditions are literally part of the vibe check:

• KTIME_MAX — when it is probable that nothing has to be done (not the only one in the level 0 group; and if it is the only one in level 0 group, but there are more than a single group active on the way to top level). 🫶
• nextevt — when CPU is offline and has to handle timer on its own or when on the way to top in every group only a single child is active but nextevt is before the lowest next_expiry encountered while walking up to top level. 😭
• next_expiry — value of lowest expiry encountered while walking groups if only a single child is active on each and nextevt is after this lowest expiry. 🔥

💜 SEE ALSO 💜

Kernel file ./kernel/time/timer_migration.c — struct tmigr_walk(9), tmigr_cpu_activate(9), tmigr_handle_remote(9), tmigr_requires_handle_remote(9), tmigr_cpu_new_timer(9), tmigr_cpu_deactivate(9), tmigr_isolated_exclude_cpumask(9). All the cross-reference lore, iykyk. 🦋🌈

This page lives in ./kernel/time, is dated October 2026, and is literally titled tmigr_quick_check(9). Slay, bye bestie! 💅✨🎀