rhltable_lookup(9)

💖 rhltable_lookup — the kernel API manual, bestie edition 💖

okay so real talk, this is rhltable_lookup(9), straight out of the kernel API manual (section 9, iykyk). it's a whole vibe and it's about to be your new fave 🦋

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✨ NAME ✨

rhltable_lookup — search a hash list table 🔍

🌸 SYNOPSIS 🌸

struct rhlist_head * rhltable_lookup (struct rhltable *hlt , const void
*key , const struct rhashtable_params params );

like, that's the whole signature. no cap, that's it. 🎀

💅 ARGUMENTS 💅

• hlt — the hash table itself. the main character of this whole operation 👑
• key — a pointer to the key you're hunting for. the thing you're tryna match 🎯
• params — the hash table parameters. the settings, the config, the ~parameters~ ⚙️

🫶 DESCRIPTION 🫶

so here's the tea ☕: it computes the hash value for the key, then traverses the bucket chain looking for an entry with an identical key. all matching entries are returned in a list 💖

⚠️ important, fr fr: this must only be called under the RCU read lock. not optional. not a suggestion. do not skip this. 🙈

and what do you get back? it returns the list of entries that match the given key. slay. ✨

🌈 SEE ALSO 🌈

the whole friend group, periodt 💜:

• Kernel file ./include/linux/rhashtable.h struct bucket_table(9)
• rht_grow_above_75(9)
• rht_shrink_below_30(9)
• rht_grow_above_100(9)
• rht_grow_above_max(9)
• rht_for_each_from(9)
• rht_for_each(9)
• rht_for_each_entry_from(9)
• rht_for_each_entry(9)
• rht_for_each_entry_safe(9)
• rht_for_each_rcu_from(9)
• rht_for_each_rcu(9)
• rht_for_each_entry_rcu_from(9)
• rht_for_each_entry_rcu(9)
• rhl_for_each_rcu(9)
• rhl_for_each_entry_rcu(9)
• rhashtable_lookup(9)
• rhashtable_lookup_fast(9)
• rhashtable_insert_fast(9)
• rhltable_insert_key(9)
• rhltable_insert(9)
• rhashtable_lookup_insert_fast(9)
• rhashtable_lookup_get_insert_fast(9)
• rhashtable_lookup_insert_key(9)
• rhashtable_lookup_get_insert_key(9)
• rhashtable_remove_fast(9)
• rhltable_remove(9)
• rhashtable_replace_fast(9)
• rhltable_walk_enter(9)
• rhltable_free_and_destroy(9)

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okay that's the whole page, go forth and look up your hash lists responsibly bestie 🧚💫

sign-off vibes only: this one lives in ./include/linux, and the date on it is October 2026 — iconic, timeless, stamped and sealed 💌🎀