diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2011-11-17 03:13:26 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-11-17 17:06:08 -0500 |
| commit | adc9300e78e6091a7eaa1821213836379d4dbaa8 (patch) | |
| tree | b2d075990b32e8c21129851bf1b1adf4cdc441f1 /net/core/sysctl_net_core.c | |
| parent | d6f144830bdfa5fcf116e9ab8fc6a60d23fa623d (diff) | |
net: use jump_label to shortcut RPS if not setup
Most machines dont use RPS/RFS, and pay a fair amount of instructions in
netif_receive_skb() / netif_rx() / get_rps_cpu() just to discover
RPS/RFS is not setup.
Add a jump_label named rps_needed.
If no device rps_map or global rps_sock_flow_table is setup,
netif_receive_skb() / netif_rx() do a single instruction instead of many
ones, including conditional jumps.
jmp +0 (if CONFIG_JUMP_LABEL=y)
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/sysctl_net_core.c')
| -rw-r--r-- | net/core/sysctl_net_core.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c index 77a65f031488..d05559d4d9cd 100644 --- a/net/core/sysctl_net_core.c +++ b/net/core/sysctl_net_core.c @@ -68,8 +68,13 @@ static int rps_sock_flow_sysctl(ctl_table *table, int write, if (sock_table != orig_sock_table) { rcu_assign_pointer(rps_sock_flow_table, sock_table); - synchronize_rcu(); - vfree(orig_sock_table); + if (sock_table) + jump_label_inc(&rps_needed); + if (orig_sock_table) { + jump_label_dec(&rps_needed); + synchronize_rcu(); + vfree(orig_sock_table); + } } } |