src/patches/suse-2.6.27.25/patches.xen/xen-netback-notify-multi

   1 From: jbeulich@novell.com
   2 Subject: netback: use multicall for send multiple notifications
   3 Patch-mainline: obsolete
   4
   5 This also does a small fairness improvement since now notifications
   6 get sent in the order requests came in rather than in the inverse one.
   7
   8 --- sle11-2009-03-24.orig/drivers/xen/core/evtchn.c     2009-03-31 13:36:56.000000000 +0200
   9 +++ sle11-2009-03-24/drivers/xen/core/evtchn.c  2009-03-31 13:37:08.000000000 +0200
  10 @@ -1294,6 +1294,21 @@ void notify_remote_via_irq(int irq)
  11  }
  12  EXPORT_SYMBOL_GPL(notify_remote_via_irq);
  13
  14 +int multi_notify_remote_via_irq(multicall_entry_t *mcl, int irq)
  15 +{
  16 +       int evtchn = evtchn_from_irq(irq);
  17 +
  18 +       BUG_ON(type_from_irq(irq) == IRQT_VIRQ);
  19 +       BUG_IF_IPI(irq);
  20 +
  21 +       if (!VALID_EVTCHN(evtchn))
  22 +               return -EINVAL;
  23 +
  24 +       multi_notify_remote_via_evtchn(mcl, evtchn);
  25 +       return 0;
  26 +}
  27 +EXPORT_SYMBOL_GPL(multi_notify_remote_via_irq);
  28 +
  29  int irq_to_evtchn_port(int irq)
  30  {
  31         BUG_IF_VIRQ_PER_CPU(irq);
  32 --- sle11-2009-03-24.orig/drivers/xen/netback/netback.c 2008-12-23 09:35:42.000000000 +0100
  33 +++ sle11-2009-03-24/drivers/xen/netback/netback.c      2008-12-23 09:35:48.000000000 +0100
  34 @@ -748,10 +748,20 @@ static void net_rx_action(unsigned long
  35                 npo.meta_cons += nr_frags + 1;
  36         }
  37
  38 -       while (notify_nr != 0) {
  39 -               irq = notify_list[--notify_nr];
  40 +       if (notify_nr == 1) {
  41 +               irq = *notify_list;
  42                 __clear_bit(irq, rx_notify);
  43                 notify_remote_via_irq(irq + DYNIRQ_BASE);
  44 +       } else {
  45 +               for (count = ret = 0; ret < notify_nr; ++ret) {
  46 +                       irq = notify_list[ret];
  47 +                       __clear_bit(irq, rx_notify);
  48 +                       if (!multi_notify_remote_via_irq(rx_mcl + count,
  49 +                                                        irq + DYNIRQ_BASE))
  50 +                               ++count;
  51 +               }
  52 +               if (HYPERVISOR_multicall(rx_mcl, count))
  53 +                       BUG();
  54         }
  55
  56         /* More work to do? */
  57 --- sle11-2009-03-24.orig/include/xen/evtchn.h  2009-03-04 11:38:25.000000000 +0100
  58 +++ sle11-2009-03-24/include/xen/evtchn.h       2008-12-01 12:10:27.000000000 +0100
  59 @@ -179,6 +179,18 @@ static inline void notify_remote_via_evt
  60         VOID(HYPERVISOR_event_channel_op(EVTCHNOP_send, &send));
  61  }
  62
  63 +static inline void
  64 +multi_notify_remote_via_evtchn(multicall_entry_t *mcl, int port)
  65 +{
  66 +       struct evtchn_send *send = (void *)(mcl->args + 2);
  67 +
  68 +       BUILD_BUG_ON(sizeof(*send) > sizeof(mcl->args) - 2 * sizeof(*mcl->args));
  69 +       send->port = port;
  70 +       mcl->op = __HYPERVISOR_event_channel_op;
  71 +       mcl->args[0] = EVTCHNOP_send;
  72 +       mcl->args[1] = (unsigned long)send;
  73 +}
  74 +
  75  /* Clear an irq's pending state, in preparation for polling on it. */
  76  void xen_clear_irq_pending(int irq);
  77
  78 @@ -197,6 +209,7 @@ void xen_poll_irq(int irq);
  79   * by bind_*_to_irqhandler().
  80   */
  81  void notify_remote_via_irq(int irq);
  82 +int multi_notify_remote_via_irq(multicall_entry_t *, int irq);
  83  int irq_to_evtchn_port(int irq);
  84
  85  #define PIRQ_SET_MAPPING 0x0