cmask_reframe(9)

💖 NAME

okay so bestie, welcome to cmask_reframe(9) — it's from the Kernel API Manual, and it's here to Reshape @m's active range without resizing storage. that's the whole vibe ✨

✨ SYNOPSIS ✨

the signature is literally giving:

void cmask_reframe (struct scx_cmask __arena *m , u32 base , u32 nr_cids
       );

🎀 ARGUMENTS 🎀

• m — the cmask to reframe, bestie. that's the main character 💅
• base — the new active range base.
• nr_cids — the new active range length; it must fit within m->alloc_words — no sneaky overflow energy, okay? 🫶

🦋 DESCRIPTION 🦋

okay so real talk: body bits within the new range become garbage 😭. only the head and tail words are zeroed, and that's specifically to keep the padding invariant. no cap, that's the whole thing.

🚨 bestie, do not forget: the body bits in the new range are toast. only the head and tail words get zeroed. periodt.

🌈 SEE ALSO 🌈

the kernel file ./tools/sched_ext/include/scx/cid.bpf.h is right there with __cmask_init(9), cmask_init(9), cmask_next_set(9), and cmask_from_cpumask(9). go click around, iykyk 🫶✨

mwah 💋 this lil page lives in ./tools/sched_ext/include/scx and is dated October 2026 — source/version and date, check, bye bestie! 🎀💖