[ovs-dev] [PATCH v2 0/3 net-next] Lockless netlink_lookup() with new concurrent hash table

[David Miller]

From: Thomas Graf <tgraf at suug.ch>
Date: Fri,  1 Aug 2014 00:56:00 +0200

> Netlink sockets are maintained in a hash table to allow efficient lookup
> via the port ID for unicast messages. However, lookups currently require
> a read lock to be taken. This series adds a new generic, resizable,
> scalable, concurrent hash table based on the paper referenced in the first
> patch. It then makes use of the new data type to implement lockless
> netlink_lookup().
> 
> Patch 3/3 to convert nft_hash is included for reference but should be
> merged via the netfilter tree. Inclusion in this series is to provide
> context for the suggested API.
> 
> Against net-next since the initial user of the new hash table is in net/
> 
> Changes:
> v1-v2:
>  - fixed traversal off-by-one as spotted by Tobias Klauser
>  - removed unlikely() from BUG_ON() as spotted by Josh Triplett
>  - new 3rd patch to convert nft_hash to rhashtable
>  - make rhashtable_insert() return void
>  - nl_sk_hash_lock must be a mutex
>  - fixed wrong name of rht_shrink_below_30()
>  - exported symbols rht_grow_above_75() and rht_shrink_below_30()
>  - allow table freeing with RCU callback

Looks great, series applied, thanks!