1. 28 8月, 2014 19 次提交
  2. 26 8月, 2014 20 次提交
  3. 25 8月, 2014 1 次提交
    • D
      Merge branch 'ndo_xmit_flush' · fe88e6dd
      David S. Miller 提交于
      Basic deferred TX queue flushing infrastructure.
      
      Over time, and specifically and more recently at the Networking
      Workshop during Kernel SUmmit in Chicago, we have discussed the idea
      of having some way to optimize transmits of multiple TX packets at
      a time.
      
      There are several areas of overhead that could be amortized with such
      schemes.  One has to do with locking and transactional overhead, the
      other has to do with device specific costs.
      
      This patch set here is more aimed at device specific costs.
      
      Typically a device queues up a packet in the TX queue and then has to
      do something to have the device start processing that new entry.
      Sometimes this is composed of doing an MMIO write to a "tail"
      register, and in other cases it can involve something as expensive as
      a hypervisor call.
      
      The basic setup defined here is that when the driver supports deferred
      TX queue flushing, ndo_start_xmit should no longer perform that
      operation.  Instead a new operation, ndo_xmit_flush, should do it.
      
      I have converted IGB and virtio_net as example initial users.  The IGB
      conversion is tested, virtio_net is not but it does compile :-)
      
      All ndo_start_xmit call sites have been abstracted behind a new helper
      called netdev_start_xmit().
      
      This just adds the infrastructure, it does not actually add any
      instances of actually doing multiple ndo_start_xmit calls per
      ndo_xmit_flush invocation.
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      fe88e6dd