Eric Lee / smarc-fsl-linux-kernel

10 Mar, 2013

2 commits

  • 731362674   tunneling: Add generic Tunnel segmentation. ... Browse Code »

    Adds generic tunneling offloading support for IPv4-UDP based
    tunnels.
    GSO type is added to request this offload for a skb.
    netdev feature NETIF_F_UDP_TUNNEL is added for hardware offloaded
    udp-tunnel support. Currently no device supports this feature,
    software offload is used.

    This can be used by tunneling protocols like VXLAN.

    CC: Jesse Gross
    Signed-off-by: Pravin B Shelar
    Acked-by: Stephen Hemminger
    Signed-off-by: David S. Miller

    Pravin B Shelar
     
  • ec5f06156   net: Kill link between CSUM and SG features. ... Browse Code »

    Earlier SG was unset if CSUM was not available for given device to
    force skb copy to avoid sending inconsistent csum.
    Commit c9af6db4c11c (net: Fix possible wrong checksum generation)
    added explicit flag to force copy to fix this issue. Therefore
    there is no need to link SG and CSUM, following patch kills this
    link between there two features.

    This patch is also required following patch in series.

    Signed-off-by: Pravin B Shelar
    Signed-off-by: David S. Miller

    Pravin B Shelar
     

16 Feb, 2013

1 commit

  • 68c331631   v4 GRE: Add TCP segmentation offload for GRE ... Browse Code »

    Following patch adds GRE protocol offload handler so that
    skb_gso_segment() can segment GRE packets.
    SKB GSO CB is added to keep track of total header length so that
    skb_segment can push entire header. e.g. in case of GRE, skb_segment
    need to push inner and outer headers to every segment.
    New NETIF_F_GRE_GSO feature is added for devices which support HW
    GRE TSO offload. Currently none of devices support it therefore GRE GSO
    always fall backs to software GSO.

    [ Compute pkt_len before ip_local_out() invocation. -DaveM ]

    Signed-off-by: Pravin B Shelar
    Signed-off-by: David S. Miller

    Pravin B Shelar
     

14 Feb, 2013

1 commit

  • c9af6db4c   net: Fix possible wrong checksum generation. ... Browse Code »

    Patch cef401de7be8c4e (net: fix possible wrong checksum
    generation) fixed wrong checksum calculation but it broke TSO by
    defining new GSO type but not a netdev feature for that type.
    net_gso_ok() would not allow hardware checksum/segmentation
    offload of such packets without the feature.

    Following patch fixes TSO and wrong checksum. This patch uses
    same logic that Eric Dumazet used. Patch introduces new flag
    SKBTX_SHARED_FRAG if at least one frag can be modified by
    the user. but SKBTX_SHARED_FRAG flag is kept in skb shared
    info tx_flags rather than gso_type.

    tx_flags is better compared to gso_type since we can have skb with
    shared frag without gso packet. It does not link SHARED_FRAG to
    GSO, So there is no need to define netdev feature for this.

    Signed-off-by: Pravin B Shelar
    Signed-off-by: David S. Miller

    Pravin B Shelar
     

28 Jan, 2013

1 commit

  • cef401de7   net: fix possible wrong checksum generation ... Browse Code »

    Pravin Shelar mentioned that GSO could potentially generate
    wrong TX checksum if skb has fragments that are overwritten
    by the user between the checksum computation and transmit.

    He suggested to linearize skbs but this extra copy can be
    avoided for normal tcp skbs cooked by tcp_sendmsg().

    This patch introduces a new SKB_GSO_SHARED_FRAG flag, set
    in skb_shinfo(skb)->gso_type if at least one frag can be
    modified by the user.

    Typical sources of such possible overwrites are {vm}splice(),
    sendfile(), and macvtap/tun/virtio_net drivers.

    Tested:

    $ netperf -H 7.7.8.84
    MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to
    7.7.8.84 () port 0 AF_INET
    Recv Send Send
    Socket Socket Message Elapsed
    Size Size Size Time Throughput
    bytes bytes bytes secs. 10^6bits/sec

    87380 16384 16384 10.00 3959.52

    $ netperf -H 7.7.8.84 -t TCP_SENDFILE
    TCP SENDFILE TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 7.7.8.84 ()
    port 0 AF_INET
    Recv Send Send
    Socket Socket Message Elapsed
    Size Size Size Time Throughput
    bytes bytes bytes secs. 10^6bits/sec

    87380 16384 16384 10.00 3216.80

    Performance of the SENDFILE is impacted by the extra allocation and
    copy, and because we use order-0 pages, while the TCP_STREAM uses
    bigger pages.

    Reported-by: Pravin Shelar
    Signed-off-by: Eric Dumazet
    Signed-off-by: David S. Miller

    Eric Dumazet
     

16 Nov, 2012

3 commits