• Eric Dumazet's avatar
    ipip: enable lockless xmits · 153f0943
    Eric Dumazet authored
    IPIP tunnels can benefit from lockless xmits, using NETIF_F_LLTX
    
    Bench on a 16 cpus machine (dual E5540 cpus), 16 threads sending
    10000000 UDP frames via one ipip tunnel (size:200 bytes per frame)
    
    Before patch :
    real	2m53.321s
    user	0m10.277s
    sys	46m0.597s
    
    After patch:
    real	0m32.063s
    user	0m9.237s
    sys	8m16.255s
    
    Last problem to solve is the contention on dst :
    
    16118.00 28.3% __ip_route_output_key         vmlinux
     6135.00 10.8% dst_release                   vmlinux
     3220.00  5.6% ip_finish_output              vmlinux
     2149.00  3.8% ip_route_output_flow          vmlinux
     1575.00  2.8% ip_append_data                vmlinux
     1481.00  2.6% ip_push_pending_frames        vmlinux
     1349.00  2.4% __xfrm_lookup                 vmlinux
     1216.00  2.1% csum_partial_copy_generic     vmlinux
     1208.00  2.1% udp_sendmsg                   vmlinux
    Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    153f0943
ipip.c 22.1 KB