1. 18 3月, 2015 1 次提交
  2. 21 2月, 2015 1 次提交
    • G
      net: Initialize all members in skb_gro_remcsum_init() · 846cd667
      Geert Uytterhoeven 提交于
      skb_gro_remcsum_init() initializes the gro_remcsum.delta member only,
      leading to compiler warnings about a possibly uninitialized
      gro_remcsum.offset member:
      
      drivers/net/vxlan.c: In function ‘vxlan_gro_receive’:
      drivers/net/vxlan.c:602: warning: ‘grc.offset’ may be used uninitialized in this function
      net/ipv4/fou.c: In function ‘gue_gro_receive’:
      net/ipv4/fou.c:262: warning: ‘grc.offset’ may be used uninitialized in this function
      
      While these are harmless for now:
        - skb_gro_remcsum_process() sets offset before changing delta,
        - skb_gro_remcsum_cleanup() checks if delta is non-zero before
          accessing offset,
      it's safer to let the initialization function initialize all members.
      Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
      Acked-by: NTom Herbert <therbert@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      846cd667
  3. 12 2月, 2015 4 次提交
    • T
      net: Infrastructure for CHECKSUM_PARTIAL with remote checsum offload · 15e2396d
      Tom Herbert 提交于
      This patch adds infrastructure so that remote checksum offload can
      set CHECKSUM_PARTIAL instead of calling csum_partial and writing
      the modfied checksum field.
      
      Add skb_remcsum_adjust_partial function to set an skb for using
      CHECKSUM_PARTIAL with remote checksum offload.  Changed
      skb_remcsum_process and skb_gro_remcsum_process to take a boolean
      argument to indicate if checksum partial can be set or the
      checksum needs to be modified using the normal algorithm.
      Signed-off-by: NTom Herbert <therbert@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      15e2396d
    • T
      net: Use more bit fields in napi_gro_cb · baa32ff4
      Tom Herbert 提交于
      This patch moves the free and same_flow fields to be bit fields
      (2 and 1 bit sized respectively). This frees up some space for u16's.
      Signed-off-by: NTom Herbert <therbert@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      baa32ff4
    • T
      net: Clarify meaning of CHECKSUM_PARTIAL for receive path · 6edec0e6
      Tom Herbert 提交于
      The current meaning of CHECKSUM_PARTIAL for validating checksums
      is that _all_ checksums in the packet are considered valid.
      However, in the manner that CHECKSUM_PARTIAL is set only the checksum
      at csum_start+csum_offset and any preceding checksums may
      be considered valid. If there are checksums in the packet after
      csum_offset it is possible they have not been verfied.
      
      This patch changes CHECKSUM_PARTIAL logic in skb_csum_unnecessary and
      __skb_gro_checksum_validate_needed to only considered checksums
      referring to csum_start and any preceding checksums (with starting
      offset before csum_start) to be verified.
      Signed-off-by: NTom Herbert <therbert@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      6edec0e6
    • T
      net: Fix remcsum in GRO path to not change packet · 26c4f7da
      Tom Herbert 提交于
      Remote checksum offload processing is currently the same for both
      the GRO and non-GRO path. When the remote checksum offload option
      is encountered, the checksum field referred to is modified in
      the packet. So in the GRO case, the packet is modified in the
      GRO path and then the operation is skipped when the packet goes
      through the normal path based on skb->remcsum_offload. There is
      a problem in that the packet may be modified in the GRO path, but
      then forwarded off host still containing the remote checksum option.
      A remote host will again perform RCO but now the checksum verification
      will fail since GRO RCO already modified the checksum.
      
      To fix this, we ensure that GRO restores a packet to it's original
      state before returning. In this model, when GRO processes a remote
      checksum option it still changes the checksum per the algorithm
      but on return from lower layer processing the checksum is restored
      to its original value.
      
      In this patch we add define gro_remcsum structure which is passed
      to skb_gro_remcsum_process to save offset and delta for the checksum
      being changed. After lower layer processing, skb_gro_remcsum_cleanup
      is called to restore the checksum before returning from GRO.
      Signed-off-by: NTom Herbert <therbert@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      26c4f7da
  4. 09 2月, 2015 2 次提交
    • E
      net:rfs: adjust table size checking · 93c1af6c
      Eric Dumazet 提交于
      Make sure root user does not try something stupid.
      
      Also make sure mask field in struct rps_sock_flow_table
      does not share a cache line with the potentially often dirtied
      flow table.
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Fixes: 567e4b79 ("net: rfs: add hash collision detection")
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      93c1af6c
    • E
      net: rfs: add hash collision detection · 567e4b79
      Eric Dumazet 提交于
      Receive Flow Steering is a nice solution but suffers from
      hash collisions when a mix of connected and unconnected traffic
      is received on the host, when flow hash table is populated.
      
      Also, clearing flow in inet_release() makes RFS not very good
      for short lived flows, as many packets can follow close().
      (FIN , ACK packets, ...)
      
      This patch extends the information stored into global hash table
      to not only include cpu number, but upper part of the hash value.
      
      I use a 32bit value, and dynamically split it in two parts.
      
      For host with less than 64 possible cpus, this gives 6 bits for the
      cpu number, and 26 (32-6) bits for the upper part of the hash.
      
      Since hash bucket selection use low order bits of the hash, we have
      a full hash match, if /proc/sys/net/core/rps_sock_flow_entries is big
      enough.
      
      If the hash found in flow table does not match, we fallback to RPS (if
      it is enabled for the rxqueue).
      
      This means that a packet for an non connected flow can avoid the
      IPI through a unrelated/victim CPU.
      
      This also means we no longer have to clear the table at socket
      close time, and this helps short lived flows performance.
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Acked-by: NTom Herbert <therbert@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      567e4b79
  5. 05 2月, 2015 2 次提交
  6. 02 2月, 2015 1 次提交
  7. 30 1月, 2015 1 次提交
  8. 15 1月, 2015 2 次提交
  9. 14 1月, 2015 1 次提交
  10. 27 12月, 2014 1 次提交
    • J
      net: Generalize ndo_gso_check to ndo_features_check · 5f35227e
      Jesse Gross 提交于
      GSO isn't the only offload feature with restrictions that
      potentially can't be expressed with the current features mechanism.
      Checksum is another although it's a general issue that could in
      theory apply to anything. Even if it may be possible to
      implement these restrictions in other ways, it can result in
      duplicate code or inefficient per-packet behavior.
      
      This generalizes ndo_gso_check so that drivers can remove any
      features that don't make sense for a given packet, similar to
      netif_skb_features(). It also converts existing driver
      restrictions to the new format, completing the work that was
      done to support tunnel protocols since the issues apply to
      checksums as well.
      
      By actually removing features from the set that are used to do
      offloading, it solves another problem with the existing
      interface. In these cases, GSO would run with the original set
      of features and not do anything because it appears that
      segmentation is not required.
      
      CC: Tom Herbert <therbert@google.com>
      CC: Joe Stringer <joestringer@nicira.com>
      CC: Eric Dumazet <edumazet@google.com>
      CC: Hayes Wang <hayeswang@realtek.com>
      Signed-off-by: NJesse Gross <jesse@nicira.com>
      Acked-by: NTom Herbert <therbert@google.com>
      Fixes: 04ffcb25 ("net: Add ndo_gso_check")
      Tested-by: NHayes Wang <hayeswang@realtek.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      5f35227e
  11. 10 12月, 2014 2 次提交
  12. 03 12月, 2014 4 次提交
  13. 25 11月, 2014 1 次提交
    • M
      ipvlan: Initial check-in of the IPVLAN driver. · 2ad7bf36
      Mahesh Bandewar 提交于
      This driver is very similar to the macvlan driver except that it
      uses L3 on the frame to determine the logical interface while
      functioning as packet dispatcher. It inherits L2 of the master
      device hence the packets on wire will have the same L2 for all
      the packets originating from all virtual devices off of the same
      master device.
      
      This driver was developed keeping the namespace use-case in
      mind. Hence most of the examples given here take that as the
      base setup where main-device belongs to the default-ns and
      virtual devices are assigned to the additional namespaces.
      
      The device operates in two different modes and the difference
      in these two modes in primarily in the TX side.
      
      (a) L2 mode : In this mode, the device behaves as a L2 device.
      TX processing upto L2 happens on the stack of the virtual device
      associated with (namespace). Packets are switched after that
      into the main device (default-ns) and queued for xmit.
      
      RX processing is simple and all multicast, broadcast (if
      applicable), and unicast belonging to the address(es) are
      delivered to the virtual devices.
      
      (b) L3 mode : In this mode, the device behaves like a L3 device.
      TX processing upto L3 happens on the stack of the virtual device
      associated with (namespace). Packets are switched to the
      main-device (default-ns) for the L2 processing. Hence the routing
      table of the default-ns will be used in this mode.
      
      RX processins is somewhat similar to the L2 mode except that in
      this mode only Unicast packets are delivered to the virtual device
      while main-dev will handle all other packets.
      
      The devices can be added using the "ip" command from the iproute2
      package -
      
      	ip link add link <master> <virtual> type ipvlan mode [ l2 | l3 ]
      Signed-off-by: NMahesh Bandewar <maheshb@google.com>
      Cc: Eric Dumazet <edumazet@google.com>
      Cc: Maciej Żenczykowski <maze@google.com>
      Cc: Laurent Chavey <chavey@google.com>
      Cc: Tim Hockin <thockin@google.com>
      Cc: Brandon Philips <brandon.philips@coreos.com>
      Cc: Pavel Emelianov <xemul@parallels.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      2ad7bf36
  14. 17 11月, 2014 1 次提交
    • E
      net: provide a per host RSS key generic infrastructure · 960fb622
      Eric Dumazet 提交于
      RSS (Receive Side Scaling) typically uses Toeplitz hash and a 40 or 52 bytes
      RSS key.
      
      Some drivers use a constant (and well known key), some drivers use a random
      key per port, making bonding setups hard to tune. Well known keys increase
      attack surface, considering that number of queues is usually a power of two.
      
      This patch provides infrastructure to help drivers doing the right thing.
      
      netdev_rss_key_fill() should be used by drivers to initialize their RSS key,
      even if they provide ethtool -X support to let user redefine the key later.
      
      A new /proc/sys/net/core/netdev_rss_key file can be used to get the host
      RSS key even for drivers not providing ethtool -x support, in case some
      applications want to precisely setup flows to match some RX queues.
      
      Tested:
      
      myhost:~# cat /proc/sys/net/core/netdev_rss_key
      11:63:99:bb:79:fb:a5:a7:07:45:b2:20:bf:02:42:2d:08:1a:dd:19:2b:6b:23:ac:56:28:9d:70:c3:ac:e8:16:4b:b7:c1:10:53:a4:78:41:36:40:74:b6:15:ca:27:44:aa:b3:4d:72
      
      myhost:~# ethtool -x eth0
      RX flow hash indirection table for eth0 with 8 RX ring(s):
          0:      0     1     2     3     4     5     6     7
      RSS hash key:
      11:63:99:bb:79:fb:a5:a7:07:45:b2:20:bf:02:42:2d:08:1a:dd:19:2b:6b:23:ac:56:28:9d:70:c3:ac:e8:16:4b:b7:c1:10:53:a4:78:41
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      960fb622
  15. 12 11月, 2014 1 次提交
  16. 11 11月, 2014 1 次提交
    • E
      net: gro: add a per device gro flush timer · 3b47d303
      Eric Dumazet 提交于
      Tuning coalescing parameters on NIC can be really hard.
      
      Servers can handle both bulk and RPC like traffic, with conflicting
      goals : bulk flows want as big GRO packets as possible, RPC want minimal
      latencies.
      
      To reach big GRO packets on 10Gbe NIC, one can use :
      
      ethtool -C eth0 rx-usecs 4 rx-frames 44
      
      But this penalizes rpc sessions, with an increase of latencies, up to
      50% in some cases, as NICs generally do not force an interrupt when
      a packet with TCP Push flag is received.
      
      Some NICs do not have an absolute timer, only a timer rearmed for every
      incoming packet.
      
      This patch uses a different strategy : Let GRO stack decides what do do,
      based on traffic pattern.
      
      Packets with Push flag wont be delayed.
      Packets without Push flag might be held in GRO engine, if we keep
      receiving data.
      
      This new mechanism is off by default, and shall be enabled by setting
      /sys/class/net/ethX/gro_flush_timeout to a value in nanosecond.
      
      To fully enable this mechanism, drivers should use napi_complete_done()
      instead of napi_complete().
      
      Tested:
       Ran 200 netperf TCP_STREAM from A to B (10Gbe mlx4 link, 8 RX queues)
      
      Without this feature, we send back about 305,000 ACK per second.
      
      GRO aggregation ratio is low (811/305 = 2.65 segments per GRO packet)
      
      Setting a timer of 2000 nsec is enough to increase GRO packet sizes
      and reduce number of ACK packets. (811/19.2 = 42)
      
      Receiver performs less calls to upper stacks, less wakes up.
      This also reduces cpu usage on the sender, as it receives less ACK
      packets.
      
      Note that reducing number of wakes up increases cpu efficiency, but can
      decrease QPS, as applications wont have the chance to warmup cpu caches
      doing a partial read of RPC requests/answers if they fit in one skb.
      
      B:~# sar -n DEV 1 10 | grep eth0 | tail -1
      Average:         eth0 811269.80 305732.30 1199462.57  19705.72      0.00
      0.00      0.50
      
      B:~# echo 2000 >/sys/class/net/eth0/gro_flush_timeout
      
      B:~# sar -n DEV 1 10 | grep eth0 | tail -1
      Average:         eth0 811577.30  19230.80 1199916.51   1239.80      0.00
      0.00      0.50
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      3b47d303
  17. 06 11月, 2014 2 次提交
  18. 04 11月, 2014 2 次提交
    • A
      netdevice: add ieee802154_ptr to net_device · 98a18b6f
      Alexander Aring 提交于
      This patch adds an ieee802154_ptr to the net_device structure.
      Furthermore the 802.15.4 subsystem will introduce a nl802154 framework
      which is similar like the nl80211 framework and a wpan_dev structure.
      The wpan_dev structure will hold additional net_device attributes like
      address options which are 802.15.4 specific. In the upcoming nl802154
      implementation we will introduce a NL802154_FLAG_NEED_WPAN_DEV like
      NL80211_FLAG_NEED_WDEV. For this flag an ieee802154_ptr in net_device is
      needed. Additional we can access the wpan_dev attributes in upper layers
      like IEEE 802.15.4 6LoWPAN easily. Current solution is a complicated
      callback interface and getting these values over subif data structure
      in mac802154.
      Signed-off-by: NAlexander Aring <alex.aring@gmail.com>
      Acked-by: NDavid S. Miller <davem@davemloft.net>
      Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
      98a18b6f
    • E
      net: shrink struct softnet_data · 4cdb1e2e
      Eric Dumazet 提交于
      flow_limit in struct softnet_data is only read from local cpu
      and can be moved to fill a hole, reducing softnet_data size by
      64 bytes on x86_64
      
      While we are at it, move output_queue, output_queue_tailp and
      completion_queue, so that rx / tx paths touch a single cache line.
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      4cdb1e2e
  19. 30 10月, 2014 1 次提交
  20. 16 10月, 2014 1 次提交
    • T
      net: Add ndo_gso_check · 04ffcb25
      Tom Herbert 提交于
      Add ndo_gso_check which a device can define to indicate whether is
      is capable of doing GSO on a packet. This funciton would be called from
      the stack to determine whether software GSO is needed to be done. A
      driver should populate this function if it advertises GSO types for
      which there are combinations that it wouldn't be able to handle. For
      instance a device that performs UDP tunneling might only implement
      support for transparent Ethernet bridging type of inner packets
      or might have limitations on lengths of inner headers.
      Signed-off-by: NTom Herbert <therbert@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      04ffcb25
  21. 09 10月, 2014 1 次提交
  22. 08 10月, 2014 1 次提交
    • E
      net: better IFF_XMIT_DST_RELEASE support · 02875878
      Eric Dumazet 提交于
      Testing xmit_more support with netperf and connected UDP sockets,
      I found strange dst refcount false sharing.
      
      Current handling of IFF_XMIT_DST_RELEASE is not optimal.
      
      Dropping dst in validate_xmit_skb() is certainly too late in case
      packet was queued by cpu X but dequeued by cpu Y
      
      The logical point to take care of drop/force is in __dev_queue_xmit()
      before even taking qdisc lock.
      
      As Julian Anastasov pointed out, need for skb_dst() might come from some
      packet schedulers or classifiers.
      
      This patch adds new helper to cleanly express needs of various drivers
      or qdiscs/classifiers.
      
      Drivers that need skb_dst() in their ndo_start_xmit() should call
      following helper in their setup instead of the prior :
      
      	dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
      ->
      	netif_keep_dst(dev);
      
      Instead of using a single bit, we use two bits, one being
      eventually rebuilt in bonding/team drivers.
      
      The other one, is permanent and blocks IFF_XMIT_DST_RELEASE being
      rebuilt in bonding/team. Eventually, we could add something
      smarter later.
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Cc: Julian Anastasov <ja@ssi.bg>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      02875878
  23. 07 10月, 2014 1 次提交
  24. 04 10月, 2014 2 次提交
    • T
      fou: eliminate IPv4,v6 specific GRO functions · efc98d08
      Tom Herbert 提交于
      This patch removes fou[46]_gro_receive and fou[46]_gro_complete
      functions. The v4 or v6 variants were chosen for the UDP offloads
      based on the address family of the socket this is not necessary
      or correct. Alternatively, this patch adds is_ipv6 to napi_gro_skb.
      This is set in udp6_gro_receive and unset in udp4_gro_receive. In
      fou_gro_receive the value is used to select the correct inet_offloads
      for the protocol of the outer IP header.
      Signed-off-by: NTom Herbert <therbert@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      efc98d08
    • E
      qdisc: validate skb without holding lock · 55a93b3e
      Eric Dumazet 提交于
      Validation of skb can be pretty expensive :
      
      GSO segmentation and/or checksum computations.
      
      We can do this without holding qdisc lock, so that other cpus
      can queue additional packets.
      
      Trick is that requeued packets were already validated, so we carry
      a boolean so that sch_direct_xmit() can validate a fresh skb list,
      or directly use an old one.
      
      Tested on 40Gb NIC (8 TX queues) and 200 concurrent flows, 48 threads
      host.
      
      Turning TSO on or off had no effect on throughput, only few more cpu
      cycles. Lock contention on qdisc lock disappeared.
      
      Same if disabling TX checksum offload.
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      55a93b3e
  25. 27 9月, 2014 1 次提交
  26. 26 9月, 2014 1 次提交
  27. 20 9月, 2014 1 次提交