scx_cmask_subset(9)

💅 scx_cmask_subset — Kernel API Manual, section 9 🎀

okay bestie, settle in, because this one is from the Kernel API Manual and it's lowkey the sweetest little boolean check you'll ever meet ✨

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🌸 NAME 🌸

scx_cmask_subset — bestie, all this does is test whether @sub is a subset of @super. that's it. that's the whole vibe check 🦋

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✨ SYNOPSIS ✨

bool scx_cmask_subset (const struct scx_cmask *sub , const struct scx_cmask *super );

like, it literally takes two cmask pointers and hands you back a bool. no cap. 💅

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🎀 ARGUMENTS 🎀

• sub — the cmask you're testing. the one being checked. the main character of the question 👑
• super — the cmask you're testing against. the big reference energy. the one doing the containing 🫶

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🧚 DESCRIPTION 🧚

so here's the whole thing: it returns true iff every single set bit of sub is also set in super. every one. no stragglers. no "close enough". if even one bit of sub is out there living its truth in super's unset territory, the answer is false, periodt 💀

that's it, that's the function. she's small, she's focused, she ate and left no crumbs 🔥

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🦋 SEE ALSO 🦋

this is the group chat, and everyone's invited 🌈. all of these live in the kernel file ./kernel/sched/ext/cid.c:

• scx_cid_publish_tables(9)
• scx_cid_retire_tables(9)
• scx_cid_init(9)
• scx_cmask_clear(9)
• scx_cmask_fill(9)
• scx_bpf_cid_override(9)
• scx_bpf_cid_to_cpu(9)
• scx_bpf_cpu_to_cid(9)
• scx_cmask_empty(9)
• scx_bpf_cid_topo(9)
• scx_cmask_ref_init(9)
• scx_cmask_ref_init_kern(9)
• scx_cmask_ref_shard(9)
• scx_cmask_ref_or(9)
• scx_cmask_ref_copy(9)
• scx_cmask_ref_from_cpumask(9)

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ngl bestie, if you're reading this page you probably also need scx_cmask_empty(9) — they're literally sisters 💖

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mwah, that's a wrap 🍓 this page came straight out of ./kernel/sched/ext and it's dated October 2026, so like… future icon behaviour honestly 💜 stay hydrated, go read your cpumasks, and remember: subset checks are free but friendship is priceless 🧚✨