Merge branch 'concurrent_hash_tables'
Thomas Graf says:
====================
Lockless netlink_lookup() with new concurrent hash table
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:
v4-v5:
- use GFP_KERNEL to alloc Netlink buckets as suggested by Nikolay
Aleksandrov
- free nft hash element on removal as spotted by Nikolay Aleksandrov
and Patrick McHardy
v3-v4:
- fixed wrong shift assignment placement as spotted by Nikolay Aleksandrov
- reverted default size of nft_hash to 4 as requested by Patrick McHardy,
default size for other hash tables remains at 64 if no hint is given
- fixed copyright as requested by Patrick McHardy
v2-v3:
- fixed typo in nft_hash_destroy() when passing rhashtable handle
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
====================
Signed-off-by: David S. Miller <davem@davemloft.net>