mpol_to_str(9)

💅 mpol_to_str — the Kernel API Manual one ✨

okay so bestie, welcome to mpol_to_str(9) from the Kernel API Manual — this is the little guy that takes a mempolicy and makes it printable. no cap, it's giving "glow-up for a struct" 🎀

🌸 NAME 🌸

mpol_to_str — format a mempolicy structure for printing 💖

✨ SYNOPSIS ✨

void mpol_to_str (char *buffer , int maxlen , struct mempolicy *pol );

🦋 ARGUMENTS 🦋

• buffer — the char buffer that's gonna contain the formatted mempolicy string. it's the canvas, she's the art 🎨
• maxlen — length of buffer. yes, you gotta tell her how much room she has. be honest with her 🙈
• pol — pointer to the mempolicy that needs to be formatted. the main character, literally 👑

💜 DESCRIPTION 💜

So what it does: it converts pol into a string. that's the whole vibe. 🫶

and if buffer is too short? she truncates the string. not a crash, not a meltdown, just a lil trim — but lowkey you don't want that, so listen up 👇

the manpage recommends a maxlen of at least 51 for the longest mode, "weighted interleave", plus the longest flag, "relative|balancing", and also so you can display at least a few node ids. that's the 51 breakdown bestie, the math is mathing 🔥

ngl, if you're eyeballing your buffer size, just give her the 51. don't do her dirty with some tiny buffer and then act surprised when it truncates 💀

🌈 SEE ALSO 🌈

Kernel file ./mm/mempolicy.c, plus the whole friend group: numa_nearest_node(9), nearest_node_nodemask(9), folio_can_map_prot_numa(9), alloc_pages_mpol(9), vma_alloc_folio(9), alloc_pages(9), mpol_misplaced(9), mpol_shared_policy_init(9), mpol_parse_str(9) — iykyk, go read them, they're iconic 🧚

and that's the page! 💅 sign-off time: this one lives in ./mm 🍓, dated October 2026 ⭐, and yeah — she's mpol_to_str(9) through and through. mwah 💖✨