cpumask_clear(9)

✨ NAME ✨

cpumask_clear — okay so this is the girl that clears, like, every cpu in a cpumask, meaning all the cpus (< nr_cpu_ids). Yes bestie, the whole thing. Wiped. Iconic behavior tbh.

This page lives in the Kernel API Manual, which is giving "the docs your kernel-dev bestie actually reads at 2am." 🫶

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🌸 SYNOPSIS 🌸

void cpumask_clear (struct cpumask *dstp );

That's it. That's the whole signature. No return value, no drama, she just does the thing and leaves. 💅

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🎀 ARGUMENTS 🎀

• dstp — the cpumask pointer 💖. This is the mask you're handing over so she can clear it. That's the whole ask. Point at your struct cpumask and she takes it from there.

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🦋 SEE ALSO 🦋

Okay so there are so many siblings, and honestly the family is huge, so buckle up. The kernel file where all this lives is ./include/linux/cpumask.h — that's the whole crew's address 🏠:

• cpumask_pr_args(9), cpumask_first(9), cpumask_first_zero(9), cpumask_first_and(9), cpumask_first_andnot(9)
• cpumask_first_and_and(9), cpumask_last(9), cpumask_next(9), cpumask_next_zero(9), cpumask_next_and(9)
• cpumask_next_andnot(9), cpumask_next_and_wrap(9), cpumask_next_wrap(9), cpumask_random(9)
• for_each_cpu(9), for_each_cpu_wrap(9), for_each_cpu_and(9), for_each_cpu_andnot(9), for_each_cpu_or(9), for_each_cpu_from(9)
• cpumask_any_but(9), cpumask_any_and_but(9), cpumask_any_andnot_but(9)
• cpumask_nth(9), cpumask_nth_and(9), cpumask_nth_and_andnot(9)
• cpumask_set_cpu(9), cpumask_clear_cpus(9), cpumask_clear_cpu(9), cpumask_test_cpu(9), cpumask_test_and_set_cpu(9), cpumask_test_and_clear_cpu(9)
• cpumask_setall(9), cpumask_and(9), cpumask_or(9), cpumask_weighted_or(9), cpumask_xor(9), cpumask_andnot(9)
• cpumask_equal(9), cpumask_or_equal(9), cpumask_intersects(9), cpumask_subset(9)
• cpumask_empty(9), cpumask_full(9), cpumask_weight(9), cpumask_weight_and(9), cpumask_weight_andnot(9)
• cpumask_shift_right(9), cpumask_shift_left(9), cpumask_copy(9)
• cpumask_any(9), cpumask_any_and(9), cpumask_of(9)
• cpumask_parse_user(9), cpumask_parselist_user(9), cpumask_parse(9), cpulist_parse(9)
• cpumask_size(9), alloc_cpumask_var(9), to_cpumask(9), num_online_cpus(9)
• cpumap_print_bitmask_to_buf(9), cpumap_print_list_to_buf(9)

Like I said. Huge family. All of them ate, no cap. 🔥

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Real talk though: this page is short on purpose. There are no extra flags, no hidden defaults, no environment variables, no exit statuses — nothing hiding in the fine print. cpumask_clear takes one pointer and clears all cpus (< nr_cpu_ids) in that mask. That's the entire vibe check. 🙈

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Okay that's the page!! 🎀 This one came out of ./include/linux and it's dated October 2026 — so mark your calendar bestie, and go clear those masks. Mwah 💖✨🧚