min_order_for_split(9)

💖 NAME 💖

okay so welcome to min_order_for_split(9), straight outta the Kernel API Manual — this page is all about min_order_for_split and getting the minimum order @folio can be split to. periodt. 💅

✨ SYNOPSIS ✨

unsigned int min_order_for_split (struct folio *folio );

🎀 ARGUMENTS 🎀

• folio — the folio to split, bestie.

🦋 DESCRIPTION 🦋

min_order_for_split tells you the minimum order folio can be split to. no cap, that's the whole vibe. ✨

if a file-backed folio is truncated, 0 will be returned. lowkey important: any subsequent split attempt should get -EBUSY from split checking code. so yeah, don't fight the split checker on that one. 😭

🌸 RETURN 🌸

folio's minimum order for split. that's the return value, and it's giving exactly what it says on the tin. 🫶

👑 SEE ALSO 👑

Kernel file ./mm/huge_memory.c, plus the whole bestie squad:

• vmf_insert_pfn_pmd(9)
• vmf_insert_pfn_pud(9)
• vmf_insert_folio_pud(9)
• touch_pmd(9)
• zap_huge_pmd(9)
• __split_unmapped_folio(9)
• folio_check_splittable(9)
• __folio_split(9)
• folio_split_unmapped(9)
• folio_split(9)

xoxo, source/version ./mm, dated October 2026, signing off as min_order_for_split(9) 💅🎀