CPUSET(3)

💅 CPUSET(3) — the cpuset_parselist & domainset_parselist manual, but make it make sense 💅

okay bestie, so this is a page out of the Library Functions Manual — it lives in the libutil corner of the world, and it's here to teach you about cpuset_parselist, domainset_parselist — utility functions for cpuset(2) handling ✨

🎀 NAME 🎀

cpuset_parselist, domainset_parselist — utility functions for cpuset(2) handling. that's the whole vibe, no cap.

📚 LIBRARY 📚

System Utilities Library — it's libutil, and you link it with -lutil. slay 🫶

🦋 SYNOPSIS 🦋

#include <sys/cpuset.h>
#include <libutil.h>

int
cpuset_parselist(const char *cpu_list, cpuset_t *mask);

int
domainset_parselist(const char *domain_policy, domainset_t *domain_mask,
    int *policyp);

🌸 DESCRIPTION 🌸

okay so first up: cpuset_parselist() — it parses a cpu-list, filling the mask. that's it, that's the job 💖

and what even is a cpu-list? bestie it's literally numbers, with - for ranges and commas separating the individual numbers, iykyk. and there's this special little icon list called “all” — if you specify that, the list includes all CPUs from the root set. main character energy fr fr 👑

then we've got domainset_parselist() — this one parses a domainset(9) memory domain allocation policy specified by domain_policy, filling the domain_mask and the policyp. two for the price of one, we love a multitasker 💅

a valid domain_policy is formatted as policy:domain-list — periodt. and if you wanna know which domain policies are even valid? go peek at the -n flag in cpuset(1), it's giving the whole list ✨

⭐ RETURN VALUES ⭐

the return values can be, like, the following:

• CPUSET_PARSE_OK — the parsing was successful 🎉 ate, no crumbs
• CPUSET_PARSE_ERROR — the cpu-list or domain-policy format is invalid 😭
• CPUSET_PARSE_GETAFFINITY — the cpuset_getaffinity(2) call has failed 💀
• CPUSET_PARSE_INVALID_CPU — the number of supported CPUs or NUMA domains has been exceeded. the maximum number being CPU_SETSIZE and DOMAINSET_SETSIZE respectively. so like… know your limits 🫠
• CPUSET_PARSE_GETDOMAIN — the cpuset_getdomain(2) call has failed 🙈

no cap: those last three are failures, not vibes. handle them, bestie.

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🌈 SEE ALSO 🌈

cpuset(1), cpuset(2), numa(4), cpuset(9), domainset(9) — go read your siblings, they're iconic too 🦋

👑 AUTHORS 👑

Jeffrey Roberson <jeff@FreeBSD.org> — legend behaviour, we stan 🫶

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and that's the page!! this lil doc came to you from Debian, dated June 24, 2025 — mwah, go parse some lists responsibly, bestie 💖🎀✨