radix_tree_replace_slot(9)

📦 version 7.3.1, in nixpkgs unstable

💅 radix_tree_replace_slot 💅

okay so bestie, this is radix_tree_replace_slot(9) from the Kernel API Manual, and it's giving “tiny function, very serious locking rules.” No cap, it's a quick little slot-swap situation with a big warning label. ✨

🎀 NAME 🎀

radix_tree_replace_slot — replace item in a slot

✨ SYNOPSIS ✨

void radix_tree_replace_slot (struct radix_tree_root *root , void __rcu
       **slot , void *item );

🌸 ARGUMENTS 🌸

  • root — the radix tree root. the main character of this whole tree situation. 👑
  • slot — pointer to slot. literally the slot pointer, bestie. 💅
  • item — the new item to store in the slot. yes, the fresh thing going in there. 🎀

🦋 DESCRIPTION 🦋

This one is for use with radix_tree_lookup_slot and radix_tree_gang_lookup_tag_slot. 🫶

The caller must hold the tree write locked across the slot lookup and the replacement. not optional, not “oops I forgot,” not a vibe. hold that write lock the whole time. 🔒

⚠️ NOTE ⚠️

This cannot be used to switch between non-entries (empty slots), regular entries, and value entries, because that requires accounting inside the radix tree node. 😭

When switching from one type of entry or deleting, use __radix_tree_lookup and __radix_tree_replace or radix_tree_iter_replace. periodt. 💀

🔗 SEE ALSO 🔗

Kernel file ./lib/radix-tree.c

mwah 💖 that's the whole page, bestie. source is ./lib, and the date/version vibe is October 2026 — go forth and replace those slots responsibly. 🧚🌸

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