list_next_or_null_rcu(9)

📦 version 7.3.1, in nixpkgs unstable

✨ list_next_or_null_rcu(9) ✨

okay so this is a page straight out of the Kernel API Manual (yes, the kernel has a manual, and yes it's lowkey iconic) — it's all about list_next_or_null_rcu, bestie. let's get into it 🎀

🌸 NAME 🌸

list_next_or_null_rcu — grab the next element from a list, and be super chill about it 💅

🦋 SYNOPSIS 🦋

list_next_or_null_rcu (head , ptr , type , member );

like literally that's the whole call. four args, no drama ✨

🎀 ARGUMENTS 🎀

  • head — the head for the list. the actual list head, the main character of the whole operation 👑
  • ptr — the list head you're taking the next element from. so we start here and look forward, iykyk
  • type — the type of the struct this is embedded in. tell the compiler what kinda struct we're living in fr fr
  • member — the name of the list_head within the struct. the lil field name that makes the magic work 🪄

💖 DESCRIPTION 💖

okay so here's the vibe check: note that if ptr is at the end of the list, NULL is returned. so no, you're not getting garbage back, you're getting a polite little NULL. we love a safe return 🫶

and the actually important part — this primitive may safely run concurrently with the _rcu list-mutation primitives such as list_add_rcu, as long as it's guarded by rcu_read_lock. that's the whole deal, no cap. concurrent reads, rcU squad, everyone stays happy 😌

⚠️ bestie please don't forget the rcu_read_lock guard. that's the entire safety story, and skipping it is not the vibe 💀

🔥 SEE ALSO 🔥

this page has SO many friends, it's giving group chat energy. all of these live in the Kernel file ./include/linux/rculist.h:

aaaand that's the page! 💜 this lil gem calls ./include/linux home, dated October 2026 — bestie that's a whole future date, main character energy fr. stay safe out there with your RCU lists, slay, periodt 🌈💅

📦 where this page comes from