alloc_cpumask_var_node(9)

🌸 NAME 🌸

okay so bestie, welcome to alloc_cpumask_var_node(9) from the Kernel API Manual — this page is literally about allocating a struct cpumask on a given node. No cap. ✨

✨ SYNOPSIS ✨

bool alloc_cpumask_var_node (cpumask_var_t *mask , gfp_t flags , int
       node );

🎀 ARGUMENTS 🎀

• mask — a pointer to cpumask_var_t, and the cpumask gets returned through it. That's the output bestie. 💅
• flags — the GFP_ flags. Yep, those flags.
• node — the memory node to allocate from, or NUMA_NO_NODE. Pick your node, or don't. 🦋

🦋 DESCRIPTION 🦋

Real talk: this whole thing is only defined when CONFIG_CPUMASK_OFFSTACK=y. If that's not the case, it's a nop returning a constant 1 (in <linux/cpumask.h>). Iconic behavior, honestly.

Also, if this fails, mask will be NULL. And note that gcc is usually smart enough to know that mask can never be NULL if CONFIG_CPUMASK_OFFSTACK=n, so it does code elimination in that case too. The compiler ate, fr fr. 🔥

🌈 RETURN 🌈

TRUE if memory allocation succeeded, FALSE otherwise. Simple as that, bestie. 🫶

👑 SEE ALSO 👑

This section is giving linked-list energy — the Kernel file ./lib/cpumask.c and these function besties:

• alloc_bootmem_cpumask_var(9)
• free_cpumask_var(9)
• free_bootmem_cpumask_var(9)
• cpumask_local_spread(9)
• cpumask_any_and_distribute(9)
• cpumask_any_distribute(9)

Cute sign-off: source/version ./lib, date October 2026, page alloc_cpumask_var_node(9) — bye bestie, go allocate responsibly! 💖🎀