preempt_schedule_notrace(9)

💖 NAME 💖

preempt_schedule_notrace — it's preempt_schedule called by tracing, and yes bestie, that's the whole vibe 💅

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✨ SYNOPSIS ✨

__visible void notrace preempt_schedule_notrace (void );

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🎀 ARGUMENTS 🎀

• void — no arguments. Not a single one, bestie. Clean. Iconic. 🫶

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🦋 DESCRIPTION 🦋

Okay so the tracing infrastructure uses preempt_enable_notrace to prevent recursion and to prevent tracing the preempt enabling caused by the tracing infrastructure itself. No cap. 🔥

But here's the plot twist 😭: tracing can happen in areas coming from userspace or just about to enter userspace, so a preempt enable can occur before user_exit is called. That will cause the scheduler to be called when the system is still in usermode. It's giving "not the moment" energy, fr fr.

To prevent this, preempt_enable_notrace will use this function instead of preempt_schedule to exit user context if needed before calling the scheduler. Slay. ✅

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🌸 SEE ALSO 🌸

Kernel file ./kernel/sched/core.c:

• wake_q_add(9)
• wake_q_add_safe(9)
• task_curr(9)
• try_to_wake_up(9)
• task_call_func(9)
• cpu_curr_snapshot(9)
• wake_up_process(9)
• preempt_notifier_register(9)
• preempt_notifier_unregister(9)
• prepare_task_switch(9)
• finish_task_switch(9)
• schedule_tail(9)
• schedule_preempt_disabled(9)
• init_idle(9)
• curr_task(9)

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That's the whole page, bestie 🫶 — source/version is ./kernel/sched, dated October 2026, and it's the preempt_schedule_notrace(9) page. periodt 💅✨