1. 22 5月, 2014 6 次提交
    • J
      wimax/i2400m: make return of 0 explicit · aff4b974
      Julia Lawall 提交于
      Delete unnecessary local variable whose value is always 0 and that hides
      the fact that the result is always 0.
      
      A simplified version of the semantic patch that fixes this problem is as
      follows: (http://coccinelle.lip6.fr/)
      
      // <smpl>
      @r exists@
      local idexpression ret;
      expression e;
      position p;
      @@
      
      -ret = 0;
      ... when != ret = e
      return
      - ret
      + 0
        ;
      // </smpl>
      Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      aff4b974
    • S
      enic: Add support for adaptive interrupt coalescing · 7c2ce6e6
      Sujith Sankar 提交于
      This patch adds support for adaptive interrupt coalescing.
      
      For small pkts with low pkt rate, we can decrease the coalescing interrupt
      dynamically which decreases the latency. This however increases the cpu
      utilization. Based on testing with different coal intr and pkt rate we came up
      with a table(mod_table) with rx_rate and coalescing interrupt value where we
      get low latency without significant increase in cpu. mod_table table stores
      the coalescing timer percentage value for different throughputs.
      
      Function enic_calc_int_moderation() calculates the desired coalescing intr timer
      value. This function is called in driver rx napi_poll. The actual value is set
      by enic_set_int_moderation() which is called when napi_poll is complete. i.e
      when we unmask the rx intr.
      
      Adaptive coal intr is support only when driver is using msix intr. Because
      intr is not shared.
      
      Struct mod_range is used to store only the default adaptive coalescing intr
      value.
      
      Adaptive coal intr calue is calculated by
      
      timer = range_start + ((rx_coal->range_end - range_start) *
      		       mod_table[index].range_percent / 100);
      
      rx_coal->range_end is the rx-usecs-high value set using ethtool.
      range_start is rx-usecs-low, set using ethtool, if rx_small_pkt_bytes_cnt is
      greater than 2 * rx_large_pkt_bytes_cnt. i.e small pkts are dominant. Else its
      rx-usecs-low + 3.
      
      Cc: Christian Benvenuti <benve@cisco.com>
      Cc: Neel Patel <neepatel@cisco.com>
      Signed-off-by: NSujith Sankar <ssujith@cisco.com>
      Signed-off-by: NGovindarajulu Varadarajan <_govind@gmx.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      7c2ce6e6
    • M
      vxge: Use time_before() · f6e92d10
      Manuel Schölling 提交于
      To be future-proof and for better readability the time comparisons are modified
      to use time_before() instead of plain, error-prone math.
      Signed-off-by: NManuel Schölling <manuel.schoelling@gmx.de>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f6e92d10
    • H
      ieee802154: Introduce the use of the managed version of kzalloc · 12b5c38f
      Himangi Saraogi 提交于
      This patch moves data allocated using kzalloc to managed data allocated
      using devm_kzalloc and cleans now unnecessary kfrees in probe and remove
      functions. An explicit linux/device.h include is added to make sure
      the devm_*() routine declarations are unambiguously available.
      
      The following Coccinelle semantic patch was used for making the change:
      
      @platform@
      identifier p, probefn, removefn;
      @@
      struct platform_driver p = {
        .probe = probefn,
        .remove = removefn,
      };
      
      @prb@
      identifier platform.probefn, pdev;
      expression e, e1, e2;
      @@
      probefn(struct platform_device *pdev, ...) {
        <+...
      - e = kzalloc(e1, e2)
      + e = devm_kzalloc(&pdev->dev, e1, e2)
        ...
      ?-kfree(e);
        ...+>
      }
      
      @rem depends on prb@
      identifier platform.removefn;
      expression e;
      @@
      removefn(...) {
        <...
      - kfree(e);
        ...>
      }
      Signed-off-by: NHimangi Saraogi <himangi774@gmail.com>
      Acked-by: NJulia Lawall <julia.lawall@lip6.fr>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      12b5c38f
    • P
      atm: idt77252: Remove redundant error check · 7e910357
      Peter Senna Tschudin 提交于
      Remove double checks, convert printk to pr_warn, and move the call to
      pr_warn to the first check. The simplified version of the coccinelle
      semantic patch that find this issue is as follows:
      
      // <smpl>
      @@
      expression E; identifier pr; expression list es;
      @@
      while(...){
      ...
      -       if (E) break;
      +       if (E){
      +               pr(es);
      +               break;
      +       }
      ...
      }
      - if(E) pr(es);
      // </smpl>
      
      Tested by compilation only.
      Signed-off-by: NPeter Senna Tschudin <peter.senna@gmail.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      7e910357
    • X
      net-tun: restructure tun_do_read for better sleep/wakeup efficiency · 9e641bdc
      Xi Wang 提交于
      tun_do_read always adds current thread to wait queue, even if a packet
      is ready to read. This is inefficient because both sleeper and waker
      want to acquire the wait queue spin lock when packet rate is high.
      
      We restructure the read function and use common kernel networking
      routines to handle receive, sleep and wakeup. With the change
      available packets are checked first before the reading thread is added
      to the wait queue.
      
      Ran performance tests with the following configuration:
      
       - my packet generator -> tap1 -> br0 -> tap0 -> my packet consumer
       - sender pinned to one core and receiver pinned to another core
       - sender send small UDP packets (64 bytes total) as fast as it can
       - sandy bridge cores
       - throughput are receiver side goodput numbers
      
      The results are
      
      baseline: 731k pkts/sec, cpu utilization at 1.50 cpus
       changed: 783k pkts/sec, cpu utilization at 1.53 cpus
      
      The performance difference is largely determined by packet rate and
      inter-cpu communication cost. For example, if the sender and
      receiver are pinned to different cpu sockets, the results are
      
      baseline: 558k pkts/sec, cpu utilization at 1.71 cpus
       changed: 690k pkts/sec, cpu utilization at 1.67 cpus
      Co-authored-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NXi Wang <xii@google.com>
      Acked-by: NMichael S. Tsirkin <mst@redhat.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      9e641bdc
  2. 21 5月, 2014 16 次提交
  3. 19 5月, 2014 12 次提交
  4. 17 5月, 2014 6 次提交