first_zones_zonelist(9)

📦 version 7.3.1, in nixpkgs unstable

✨ first_zones_zonelist(9) ✨

okay bestie, welcome to the Kernel API Manual entry for first_zones_zonelist — and yes it's a (9) page, we're in the big leagues now 💅

🌸 NAME 🌸

first_zones_zonelist — literally returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist 🦋

🎀 SYNOPSIS 🎀

struct zoneref * first_zones_zonelist (struct zonelist *zonelist , enum
zone_type highest_zoneidx , const nodemask_t *nodes );

that's the whole vibe, no cap ✨

💖 ARGUMENTS 💖

  • zonelist — the zonelist you're searching through to find a suitable zone 🔍
  • highest_zoneidx — the zone index of the highest zone to return, like the ceiling of your search 👑
  • nodes — an optional nodemask to filter the zonelist with (optional!! so you can pass nothing and it's still chill) 🌈

🧚 DESCRIPTION 🧚

okay so here's the tea 🍓 — this function returns the first zone at or below a given zone index that's also within the allowed nodemask.

the zoneref you get back is a cursor, iykyk 👀 — you can use it to iterate the zonelist with next_zones_zonelist by advancing it by one before calling. so it's not just a one-and-done answer, it's your starting point for the whole journey 🫶

and now the serious part, bestie, don't skip this 💀 — when no eligible zone is found, zoneref->zone is NULL (but zoneref itself is never NULL, she's always there, just maybe empty inside 😭). this can happen either genuinely, or due to a concurrent nodemask update due to cpuset modification. yes, race conditions are real, stay safe out there 🙈

⭐ RETURN ⭐

a zoneref pointer for the first suitable zone found 🔥

🦋 SEE ALSO 🦋

kernel file ./include/linux/mmzone.h is doing a whole lot, and while you're in there check out these iconic siblings:

periodt 💜

and that's the whole page, bestie, you ate that 📚✨ this one came from ./include/linux, dated October 2026, and it's first_zones_zonelist(9) — go forth and find your first suitable zone, ily 💖🎀🧚

📦 where this page comes from