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author | Thomas Graf <tgraf@suug.ch> | 2014-08-02 11:47:45 +0200 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2014-08-02 19:49:38 -0700 |
commit | e341694e3eb57fcda9f1adc7bfea42fe080d8d7a (patch) | |
tree | 12ac538a44609b3075bfaf98999ba68d9ff575cc /net/netlink/af_netlink.h | |
parent | 7e1e77636e36075ebf118298855268468f1028e8 (diff) | |
download | linux-stable-e341694e3eb57fcda9f1adc7bfea42fe080d8d7a.tar.gz linux-stable-e341694e3eb57fcda9f1adc7bfea42fe080d8d7a.tar.bz2 linux-stable-e341694e3eb57fcda9f1adc7bfea42fe080d8d7a.zip |
netlink: Convert netlink_lookup() to use RCU protected hash table
Heavy Netlink users such as Open vSwitch spend a considerable amount of
time in netlink_lookup() due to the read-lock on nl_table_lock. Use of
RCU relieves the lock contention.
Makes use of the new resizable hash table to avoid locking on the
lookup.
The hash table will grow if entries exceeds 75% of table size up to a
total table size of 64K. It will automatically shrink if usage falls
below 30%.
Also splits nl_table_lock into a separate mutex to protect hash table
mutations and allow synchronize_rcu() to sleep while waiting for readers
during expansion and shrinking.
Before:
9.16% kpktgend_0 [openvswitch] [k] masked_flow_lookup
6.42% kpktgend_0 [pktgen] [k] mod_cur_headers
6.26% kpktgend_0 [pktgen] [k] pktgen_thread_worker
6.23% kpktgend_0 [kernel.kallsyms] [k] memset
4.79% kpktgend_0 [kernel.kallsyms] [k] netlink_lookup
4.37% kpktgend_0 [kernel.kallsyms] [k] memcpy
3.60% kpktgend_0 [openvswitch] [k] ovs_flow_extract
2.69% kpktgend_0 [kernel.kallsyms] [k] jhash2
After:
15.26% kpktgend_0 [openvswitch] [k] masked_flow_lookup
8.12% kpktgend_0 [pktgen] [k] pktgen_thread_worker
7.92% kpktgend_0 [pktgen] [k] mod_cur_headers
5.11% kpktgend_0 [kernel.kallsyms] [k] memset
4.11% kpktgend_0 [openvswitch] [k] ovs_flow_extract
4.06% kpktgend_0 [kernel.kallsyms] [k] _raw_spin_lock
3.90% kpktgend_0 [kernel.kallsyms] [k] jhash2
[...]
0.67% kpktgend_0 [kernel.kallsyms] [k] netlink_lookup
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Reviewed-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/netlink/af_netlink.h')
-rw-r--r-- | net/netlink/af_netlink.h | 18 |
1 files changed, 4 insertions, 14 deletions
diff --git a/net/netlink/af_netlink.h b/net/netlink/af_netlink.h index 0b59d441f5b6..60f631fb7087 100644 --- a/net/netlink/af_netlink.h +++ b/net/netlink/af_netlink.h @@ -1,6 +1,7 @@ #ifndef _AF_NETLINK_H #define _AF_NETLINK_H +#include <linux/rhashtable.h> #include <net/sock.h> #define NLGRPSZ(x) (ALIGN(x, sizeof(unsigned long) * 8) / 8) @@ -47,6 +48,8 @@ struct netlink_sock { struct netlink_ring tx_ring; atomic_t mapped; #endif /* CONFIG_NETLINK_MMAP */ + + struct rhash_head node; }; static inline struct netlink_sock *nlk_sk(struct sock *sk) @@ -54,21 +57,8 @@ static inline struct netlink_sock *nlk_sk(struct sock *sk) return container_of(sk, struct netlink_sock, sk); } -struct nl_portid_hash { - struct hlist_head *table; - unsigned long rehash_time; - - unsigned int mask; - unsigned int shift; - - unsigned int entries; - unsigned int max_shift; - - u32 rnd; -}; - struct netlink_table { - struct nl_portid_hash hash; + struct rhashtable hash; struct hlist_head mc_list; struct listeners __rcu *listeners; unsigned int flags; |