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author | Eric Dumazet <edumazet@google.com> | 2016-12-08 11:41:56 -0800 |
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committer | David S. Miller <davem@davemloft.net> | 2016-12-09 22:12:21 -0500 |
commit | 6b229cf77d683f634f0edd876c6d1015402303ad (patch) | |
tree | ec877d3e324da74f7bbb179d4cd4a8db0172865c /include/linux/udp.h | |
parent | c84d949057cab262b4d3110ead9a42a58c2958f7 (diff) | |
download | linux-6b229cf77d683f634f0edd876c6d1015402303ad.tar.gz linux-6b229cf77d683f634f0edd876c6d1015402303ad.tar.bz2 linux-6b229cf77d683f634f0edd876c6d1015402303ad.zip |
udp: add batching to udp_rmem_release()
If udp_recvmsg() constantly releases sk_rmem_alloc
for every read packet, it gives opportunity for
producers to immediately grab spinlocks and desperatly
try adding another packet, causing false sharing.
We can add a simple heuristic to give the signal
by batches of ~25 % of the queue capacity.
This patch considerably increases performance under
flood by about 50 %, since the thread draining the queue
is no longer slowed by false sharing.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/udp.h')
-rw-r--r-- | include/linux/udp.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/udp.h b/include/linux/udp.h index d1fd8cd39478..c0f530809d1f 100644 --- a/include/linux/udp.h +++ b/include/linux/udp.h @@ -79,6 +79,9 @@ struct udp_sock { int (*gro_complete)(struct sock *sk, struct sk_buff *skb, int nhoff); + + /* This field is dirtied by udp_recvmsg() */ + int forward_deficit; }; static inline struct udp_sock *udp_sk(const struct sock *sk) |