kernel/linux.git/include/linux/rhashtable.h, branch v6.19.11

rhashtable: use likely for rhashtable lookup

2025-10-20T04:10:28+00:00

Sometimes, the result of the rhashtable_lookup() is expected to be found. Therefore, we can use likely() for such cases. Following new functions are introduced, which will use likely or unlikely during the lookup: rhashtable_lookup_likely rhltable_lookup_likely A micro-benchmark is made for these new functions: lookup a existed entry repeatedly for 100000000 times, and rhashtable_lookup_likely() gets ~30% speedup. Signed-off-by: Menglong Dong Signed-off-by: Herbert Xu

rhashtable: Use rcu_dereference_all and rcu_dereference_all_check

2025-09-20T12:21:03+00:00

Add rcu_dereference_all and rcu_dereference_all_check so that library code such as rhashtable can be used with any RCU variant. As it stands rcu_dereference is used within rashtable, which creates false-positive warnings if the user calls it from another RCU context, such as preempt_disable(). Use the rcu_dereference_all and rcu_dereference_all_check calls in rhashtable to suppress these warnings. Also replace the rcu_dereference_raw calls in the list iterators with rcu_dereference_all to uncover buggy calls. Reported-by: Menglong Dong Signed-off-by: Herbert Xu Reviewed-by: Paul E. McKenney Signed-off-by: Herbert Xu

rhashtable: Use __always_inline instead of inline

2025-09-06T07:57:23+00:00

Sometimes, the compiler is not clever enough to inline the rhashtable_lookup() for us, even if the "obj_cmpfn" and "key_len" in params is const. This can introduce more overhead. Therefore, use __always_inline for the rhashtable. Signed-off-by: Menglong Dong Signed-off-by: Herbert Xu

rhashtable: remove needless return in three void APIs

2025-03-17T06:24:15+00:00

Remove needless 'return' in the following void APIs: rhltable_walk_enter() rhltable_free_and_destroy() rhltable_destroy() Since both the API and callee involved are void functions. Link: https://lkml.kernel.org/r/20250221-rmv_return-v1-16-cc8dff275827@quicinc.com Signed-off-by: Zijun Hu Signed-off-by: Andrew Morton

rhashtable: Improve grammar

2024-04-03T01:03:32+00:00

Change "a" to "an" according to the usual rules, fix an "if" that was mistyped as "in", improve grammar in "considerable slow" -> "considerably slower". Signed-off-by: Jonathan Neuschäfer Reviewed-by: Randy Dunlap Link: https://lore.kernel.org/r/20240329-misc-rhashtable-v1-1-5862383ff798@gmx.net Signed-off-by: Jakub Kicinski

rhashtable: Allow rhashtable to be used from irq-safe contexts

2022-12-09T10:42:56+00:00

rhashtable currently only does bh-safe synchronization making it impossible to use from irq-safe contexts. Switch it to use irq-safe synchronization to remove the restriction. v2: Update the lock functions to return the ulong flags value and unlock functions to take the value directly instead of passing around the pointer. Suggested by Linus. Signed-off-by: Tejun Heo Reviewed-by: David Vernet Acked-by: Josh Don Acked-by: Hao Luo Acked-by: Barret Rhoden Cc: Linus Torvalds Signed-off-by: David S. Miller

rhashtable: Restore RCU marking on rhash_lock_head

2020-07-29T00:09:49+00:00

This patch restores the RCU marking on bucket_table->buckets as it really does need RCU protection. Its removal had led to a fatal bug. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller

rhashtable: Fix unprotected RCU dereference in __rht_ptr

2020-07-29T00:09:49+00:00

The rcu_dereference call in rht_ptr_rcu is completely bogus because we've already dereferenced the value in __rht_ptr and operated on it. This causes potential double readings which could be fatal. The RCU dereference must occur prior to the comparison in __rht_ptr. This patch changes the order of RCU dereference so that it is done first and the result is then fed to __rht_ptr. The RCU marking changes have been minimised using casts which will be removed in a follow-up patch. Fixes: ba6306e3f648 ("rhashtable: Remove RCU marking from...") Reported-by: "Gong, Sishuai" Signed-off-by: Herbert Xu Signed-off-by: David S. Miller

rhashtable: drop duplicated word in

2020-07-18T01:34:18+00:00

Drop the doubled word "be" in a comment. Signed-off-by: Randy Dunlap Cc: Thomas Graf Cc: Herbert Xu Cc: netdev@vger.kernel.org Signed-off-by: David S. Miller

rhashtable: Document the right function parameters

2020-03-07T06:33:38+00:00

rhashtable_lookup_get_insert_key doesn't have a parameter `data`. It does have a parameter `key`, however. Signed-off-by: Jonathan Neuschäfer Acked-by: Herbert Xu Signed-off-by: David S. Miller