rhashtable_shrink(9)

📦 version 7.3.1, in nixpkgs unstable

💖 rhashtable_shrink(9) — like, the Kernel API Manual page you actually wanna read 💖

okay so bestie, welcome to the rhashtable_shrink page from the Kernel API Manual — section 9, kernel territory, we're in the big leagues now 🧚✨ grab ur matcha, this one's short but she's important.

✨ NAME ✨

rhashtable_shrink — shrink a hash table while still letting concurrent lookups happen, no cap 👑

🌸 SYNOPSIS 🌸

int rhashtable_shrink (struct rhashtable *ht );

🎀 ARGUMENTS 🎀

  • ht — the hash table u wanna shrink. that's it. that's the whole argument. iconic minimalism 💅

🦋 DESCRIPTION 🦋

so what she does: this function shrinks the hash table to fit — meaning it makes it the smallest size that wouldn't cause it to expand right away automatically. like, she's not gonna yeet it down to a size where it immediately bounces back up, that would be embarrassing 😭 she picks the right size. periodt.

now the rules, and bestie these are non-negotiable 🙈:

  • the caller must make sure no concurrent resizing is happening, by holding ht->mutex. hold the mutex. hold it. 🔒
  • the caller must make sure no concurrent table mutations are taking place. no sneaky edits while she's working, fr fr.
  • it is however valid to have concurrent lookups, as long as they're RCU protected. reads are fine, she's chill with reads 🫶
  • it is valid to have concurrent insertions and deletions protected by per bucket locks, or concurrent RCU protected lookups and traversals. so those combos slay, ur good 💜
bestie pls don't skip the mutex part. that's the whole vibe check of this function. no mutex = chaos, and not the cute kind 💀

🔥 SEE ALSO 🔥

like, the whole rhashtable friend group 😭 go read the rest of them, they're all in ./lib and they all ate 💖

and that's the page, bestie!! 🎀✨ this lil beauty lives in ./lib, dated October 2026, and yes she's filed as rhashtable_shrink(9) — go forth and shrink responsibly, mwah 💅💜

📦 where this page comes from