scx_rescue_timerfn(9)

okay bestie, welcome to scx_rescue_timerfn — that's the page name, and this whole thing lives in the Kernel API Manual, section 9. grab a strawberry 🍓 and let's get into it.

✨ NAME ✨

scx_rescue_timerfn — drive and pace rescue execution. yes, it's giving scheduler main-character energy 💅

🦋 SYNOPSIS 🦋

void scx_rescue_timerfn (struct timer_list *timer );

🎀 ARGUMENTS 🎀

• timer — literally rq->scx.rescue.timer. that's the timer being passed in, no cap ✨

💅 DESCRIPTION 💅

okay so this timer function runs every quarter quantum while a rescuee exists — whether that rescuee is pending or admitted. see scx_rescue_timer_arm. 🫶

the head waiter gets admitted once the bucket holds a full quantum, and it's granted its slice — see scx_rescue_next_slice. iconic behavior, honestly.

if a session's budget accumulates over two quanta while the admitted rescuee is still waiting, that's an escalation: the rescuee's remaining slice turns into protected execution, and it preempts the current task. dramatic? yes. correct? also yes. 😭🔥

and if the rescue queue gets overloaded, it ejects the top consumer — see scx_rescue_check_overload. vibe check: failed, bestie 💀

👑 SEE ALSO 👑

go peek at these, iykyk:

• Kernel file ./kernel/sched/ext/sub.c
• scx_skip_subtree_pre(9)
• scx_next_descendant_pre(9)
• scx_rescue_charge(9)
• scx_rescue_end(9)
• scx_rescue_keep(9)
• scx_rescue_accrue(9)
• scx_rescue_admit(9)
• scx_rescue_try_admit(9)
• scx_rescue_check_overload(9)
• scx_resolve_local_dsq(9)
• queue_sync_ecaps(9)
• scx_process_sync_ecaps(9)
• scx_unbypass_replay_ecaps(9)
• scx_discard_stale_ecaps_syncs(9)
• scx_rehome_task(9)
• scx_punt_task(9)
• scx_cgroup_claim_subtree(9)
• scx_cgroup_return_subtree(9)
• scx_cgroup_task_migrating(9)
• scx_cgroup_task_migrated(9)
• scx_cgroup_task_migrate_canceled(9)
• scx_bpf_sub_dispatch(9)
• scx_bpf_sub_grant(9)
• scx_bpf_sub_revoke(9)
• scx_bpf_sub_caps(9)
• scx_bpf_sub_kill_bstr(9)

source/version check, bestie: ./kernel/sched/ext, October 2026, page scx_rescue_timerfn(9). that's the whole vibe 💖🎀🦋