1. 20 May, 2009 21 commits
  2. 19 May, 2009 17 commits
  3. 18 May, 2009 2 commits
    • Eric Dumazet's avatar
      net: release dst entry in dev_hard_start_xmit() · 93f154b5
      Eric Dumazet authored
      One point of contention in high network loads is the dst_release() performed
      when a transmited skb is freed. This is because NIC tx completion calls
      dev_kree_skb() long after original call to dev_queue_xmit(skb).
      
      CPU cache is cold and the atomic op in dst_release() stalls. On SMP, this is
      quite visible if one CPU is 100% handling softirqs for a network device,
      since dst_clone() is done by other cpus, involving cache line ping pongs.
      
      It seems right place to release dst is in dev_hard_start_xmit(), for most
      devices but ones that are virtual, and some exceptions.
      
      David Miller suggested to define a new device flag, set in alloc_netdev_mq()
      (so that most devices set it at init time), and carefuly unset in devices
      which dont want a NULL skb->dst in their ndo_start_xmit().
      
      List of devices that must clear this flag is :
      
      - loopback device, because it calls netif_rx() and quoting Patrick :
          "ip_route_input() doesn't accept loopback addresses, so loopback packets
           already need to have a dst_entry attached."
      - appletalk/ipddp.c : needs skb->dst in its xmit function
      
      - And all devices that call again dev_queue_xmit() from their xmit function
      (as some classifiers need skb->dst) : bonding, vlan, macvlan, eql, ifb, hdlc_fr
      Signed-off-by: default avatarEric Dumazet <dada1@cosmosbay.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      93f154b5
    • Eric W. Biederman's avatar
      net: FIX bonding sysfs rtnl_lock deadlock · 496a60cd
      Eric W. Biederman authored
      Sysfs files for a network device can not unconditionally take the
      rtnl_lock as the bonding sysfs files do.  If someone accesses those
      sysfs files while the network device is being unregistered with the
      rtnl_lock held we will deadlock.
      
      So use trylock and restart_syscall to avoid this problem.
      Signed-off-by: default avatarEric W. Biederman <ebiederm@aristanetworks.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      496a60cd