set_cpus_allowed_ptr(9)

💅 set_cpus_allowed_ptr — kernel API manual, but make it cute

okay so bestie, we're in the Kernel API Manual today and the star of the show is set_cpus_allowed_ptr ✨ literally the function that sets the CPU affinity mask of a task. that's it, that's the vibe. icl it's giving "i decide which CPUs you get to hang out with" 👑

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🎀 NAME 🎀

set_cpus_allowed_ptr — set CPU affinity mask of a task 🧚

like, it picks which CPU(s) a task is allowed to run on. main character energy for the task, honestly.

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✨ SYNOPSIS ✨

int set_cpus_allowed_ptr (struct task_struct *p , const struct cpumask
*new_mask );

no cap, that's the whole signature — copy it exactly, don't come for me 🙈

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🦋 ARGUMENTS 🦋

• p — the task 💖 like, the actual task you're doing this to
• new_mask — CPU affinity mask 🌸 the shiny new set of CPUs you're handing over

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🌈 RETURN 🌈

returns zero if it all went slay ✅ or a negative error code if it did not 😭 (iykyk, negative error codes are never the vibe)

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💜 SEE ALSO 💜

• kernel file ./include/linux/sched.h
• struct prev_cputime(9)
• __task_lazy_mmu_mode_active(9)
• is_lazy_mmu_mode_active(9)
• task_nice(9)
• is_idle_task(9)

go read those too fr fr, they're all in the group chat 📚🫶

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ok tiny reminder bestie: zero means success, negative means error — don't flip it, that's not the assignment 💀

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and that's the whole page, periodt 💅 this one lives in ./include/linux (source ./include/linux) and it's dated October 2026 — so yes she's from the future, and she ate 🌟🎀 bye bestie, mwah 🫶💖