1. 22 7月, 2016 4 次提交
  2. 21 7月, 2016 33 次提交
  3. 20 7月, 2016 3 次提交
    • B
      net/mlx4_en: add xdp forwarding and data write support · 9ecc2d86
      Brenden Blanco 提交于
      A user will now be able to loop packets back out of the same port using
      a bpf program attached to xdp hook. Updates to the packet contents from
      the bpf program is also supported.
      
      For the packet write feature to work, the rx buffers are now mapped as
      bidirectional when the page is allocated. This occurs only when the xdp
      hook is active.
      
      When the program returns a TX action, enqueue the packet directly to a
      dedicated tx ring, so as to avoid completely any locking. This requires
      the tx ring to be allocated 1:1 for each rx ring, as well as the tx
      completion running in the same softirq.
      
      Upon tx completion, this dedicated tx ring recycles pages without
      unmapping directly back to the original rx ring. In steady state tx/drop
      workload, effectively 0 page allocs/frees will occur.
      
      In order to separate out the paths between free and recycle, a
      free_tx_desc func pointer is introduced that is optionally updated
      whenever recycle_ring is activated. By default the original free
      function is always initialized.
      Signed-off-by: NBrenden Blanco <bblanco@plumgrid.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      9ecc2d86
    • B
      net/mlx4_en: break out tx_desc write into separate function · 224e92e0
      Brenden Blanco 提交于
      In preparation for writing the tx descriptor from multiple functions,
      create a helper for both normal and blueflame access.
      Signed-off-by: NBrenden Blanco <bblanco@plumgrid.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      224e92e0
    • B
      net/mlx4_en: add page recycle to prepare rx ring for tx support · d576acf0
      Brenden Blanco 提交于
      The mlx4 driver by default allocates order-3 pages for the ring to
      consume in multiple fragments. When the device has an xdp program, this
      behavior will prevent tx actions since the page must be re-mapped in
      TODEVICE mode, which cannot be done if the page is still shared.
      
      Start by making the allocator configurable based on whether xdp is
      running, such that order-0 pages are always used and never shared.
      
      Since this will stress the page allocator, add a simple page cache to
      each rx ring. Pages in the cache are left dma-mapped, and in drop-only
      stress tests the page allocator is eliminated from the perf report.
      
      Note that setting an xdp program will now require the rings to be
      reconfigured.
      
      Before:
       26.91%  ksoftirqd/0  [mlx4_en]         [k] mlx4_en_process_rx_cq
       17.88%  ksoftirqd/0  [mlx4_en]         [k] mlx4_en_alloc_frags
        6.00%  ksoftirqd/0  [mlx4_en]         [k] mlx4_en_free_frag
        4.49%  ksoftirqd/0  [kernel.vmlinux]  [k] get_page_from_freelist
        3.21%  swapper      [kernel.vmlinux]  [k] intel_idle
        2.73%  ksoftirqd/0  [kernel.vmlinux]  [k] bpf_map_lookup_elem
        2.57%  swapper      [mlx4_en]         [k] mlx4_en_process_rx_cq
      
      After:
       31.72%  swapper      [kernel.vmlinux]       [k] intel_idle
        8.79%  swapper      [mlx4_en]              [k] mlx4_en_process_rx_cq
        7.54%  swapper      [kernel.vmlinux]       [k] poll_idle
        6.36%  swapper      [mlx4_core]            [k] mlx4_eq_int
        4.21%  swapper      [kernel.vmlinux]       [k] tasklet_action
        4.03%  swapper      [kernel.vmlinux]       [k] cpuidle_enter_state
        3.43%  swapper      [mlx4_en]              [k] mlx4_en_prepare_rx_desc
        2.18%  swapper      [kernel.vmlinux]       [k] native_irq_return_iret
        1.37%  swapper      [kernel.vmlinux]       [k] menu_select
        1.09%  swapper      [kernel.vmlinux]       [k] bpf_map_lookup_elem
      Signed-off-by: NBrenden Blanco <bblanco@plumgrid.com>
      Acked-by: NAlexei Starovoitov <ast@kernel.org>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      d576acf0