PMAP_PAGE_EXISTS_QUICK(9)

💖 PMAP_PAGE_EXISTS_QUICK 💖

okay bestie, this one lives in section 9 of the Kernel Developer's Manual, and it's literally called pmap_page_exists_quick — yes the name is a whole mouthful, she's giving "I do one thing and I do it fast" energy 💅

✨ NAME ✨

pmap_page_exists_quick — determine if a page exists in a physical map 🦋

✨ SYNOPSIS ✨

#include <sys/param.h>
#include <vm/vm.h>
#include <vm/pmap.h>

boolean_t
pmap_page_exists_quick(pmap_t pmap, vm_page_t m);

✨ DESCRIPTION ✨

so the way this works is: pmap_page_exists_quick() is your girl for quickly figuring out whether the page m exists in the physical map pmap. that's it. that's the whole job. no cap 💖

she's typically called from the VM paging code, so like… she's not out here doing main character solo work, she's the supporting bestie that the paging code relies on, and honestly? iconic. 👑

✨ IMPLEMENTATION NOTES ✨

ngl, the PV count used above may be changed upwards or downwards in future — so don't get too attached to the exact number, bestie, it's giving "we might rearrange the furniture" 🛋️✨

the only thing that actually has to stay true is this: it's only necessary that TRUE be returned for a small subset of pmaps for proper page aging. that's the vibe. that's the contract. periodt. 🎀

✨ RETURN VALUES ✨

pmap_page_exists_quick() returns TRUE only if the PV entry for the physical map pmap is one of the first 16 PVs linked from the page m. 💀

like… it's not out here checking every single PV, she's checking the first sixteen and that's the whole point — quick means quick, iykyk 🔥

✨ SEE ALSO ✨

• pmap(9)

✨ AUTHORS ✨

this manual page was written by Bruce M Simpson <bms@spc.org> 🫶

and that's the whole page babes!! she's from Debian, dated July 21, 2003, and she's filed under PMAP_PAGE_EXISTS_QUICK(9) — go forth and check those PVs, bestie 🌸💜✨