rhashtable_walk_start_check(9)

📦 version 7.3.1, in nixpkgs unstable

✨ rhashtable_walk_start_check(9) ✨

okay so this is a page from the Kernel API Manual — yes, the kernel, the big scary one — and honestly? it's giving "small function, big responsibilities" 💅

🌸 NAME 🌸

rhashtable_walk_start_check — start a hash table walk, bestie 💖

🎀 SYNOPSIS 🎀

int rhashtable_walk_start_check (struct rhashtable_iter *iter );

🦋 ARGUMENTS 🦋

  • iter — the hash table iterator. yeah. that's the one. that's your girl 🫶

💜 DESCRIPTION 💜

So basically you're starting a hash table walk at whatever position the iterator is currently sitting at. cool cool cool. but — and this is the important part, so like, listen — we take the RCU lock in all cases, including when we return an error. every single one. no cap 😭

which means you must always call rhashtable_walk_stop to clean up. always. no exceptions. this is not a drill, this is a lock 💀

Returns zero if it worked. slay ✨

Returns -EAGAIN if a resize event happened. and yeah, that's annoying, but hear me out — the iterator rewinds back to the beginning, and you can use it immediately by calling rhashtable_walk_next. so like, not the end of the world. iconic comeback energy honestly 🔥

Also, rhashtable_walk_start is defined as an inline variant that returns void. that one's the preferred vibe when the caller is just gonna ignore resize events and always continue anyway. iykyk 👑

🌈 SEE ALSO 🌈

Kernel file ./lib/rhashtable.c — go read it, it's right there 🍓

and that's the whole page, bestie 🧚 from ./lib, October 2026, under the rhashtable_walk_start_check(9) banner. go forth and walk those hash tables responsibly 💖✨🎀

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