mem_cgroup_iter(9)

📦 version 7.3.1, in nixpkgs unstable

💖 NAME 💖

okay bestie, this is mem_cgroup_iter from the Kernel API Manual (yes, the mem_cgroup_iter(9) girlies know) — it's the function that lets you iterate over the memory cgroup hierarchy. slay. 🌸

✨ SYNOPSIS ✨

struct mem_cgroup * mem_cgroup_iter (struct mem_cgroup *root , struct
mem_cgroup *prev , struct mem_cgroup_reclaim_cookie *reclaim );

🎀 ARGUMENTS 🎀

  • root — the hierarchy root, aka where the walk starts. main character energy.
  • prev — the previously returned memcg, and it's NULL on first invocation. first time? no notes. 💅
  • reclaim — the cookie for shared reclaim walks, or NULL for full walks. choose your fighter.

🦋 DESCRIPTION 🦋

It returns references to children of the hierarchy below root, or root itself, or NULL after a full round-trip. like it literally hands you the whole tour and then a little NULL at the end to say "that's the whole loop, periodt." 🫶

The caller must pass the return value in prev on subsequent invocations for reference counting, or use mem_cgroup_iter_break to cancel a hierarchy walk before the round-trip is complete. no skipping the reference counting, bestie, that's the whole vibe. 😭

Reclaimers can specify a node in reclaim to divide up the memcgs in the hierarchy among all concurrent reclaimers operating on the same node. it's giving "share the aux cord at the function" ngl. 🎧

🌈 SEE ALSO 🌈

Kernel file ./mm/memcontrol.c — and the whole friend group:

that's the whole page, babes — sourced from ./mm, dated October 2026, and proudly titled mem_cgroup_iter(9). go forth and iterate responsibly 💜✨

📦 where this page comes from