src/patches/suse-2.6.27.25/patches.arch/s390-03-04-qdio_multicast_performance.patch

   1 From: Gerald Schaefer <geraldsc@de.ibm.com>
   2 Subject: dasd: fix  message flood for unsolicited interrupts
   3 References: bnc#440610
   4
   5 Symptom:     The message log is flooded with messages for unsolicited
   6              interrupts and missing sense data.
   7 Problem:     CIO generates fake IRBs which are falsly interpreted as
   8              unsolicited interrupts.
   9 Solution:    Ignore fake IRBs in unsolicited interupt handler.
  10
  11 Acked-by: John Jolly <jjolly@suse.de>
  12 ---
  13  drivers/s390/cio/qdio.h      |    8 ++++++++
  14  drivers/s390/cio/qdio_main.c |    6 ++++++
  15  2 files changed, 14 insertions(+)
  16
  17 Index: linux-sles11/drivers/s390/cio/qdio.h
  18 ===================================================================
  19 --- linux-sles11.orig/drivers/s390/cio/qdio.h
  20 +++ linux-sles11/drivers/s390/cio/qdio.h
  21 @@ -16,6 +16,14 @@
  22  #define QDIO_BUSY_BIT_GIVE_UP          2000000 /* 2 seconds = eternity */
  23  #define QDIO_INPUT_THRESHOLD           500     /* 500 microseconds */
  24
  25 +/*
  26 + * if an asynchronous HiperSockets queue runs full, the 10 seconds timer wait
  27 + * till next initiative to give transmitted skbs back to the stack is too long.
  28 + * Therefore polling is started in case of multicast queue is filled more
  29 + * than 50 percent.
  30 + */
  31 +#define QDIO_IQDIO_POLL_LVL            65      /* HS multicast queue */
  32 +
  33  enum qdio_irq_states {
  34         QDIO_IRQ_STATE_INACTIVE,
  35         QDIO_IRQ_STATE_ESTABLISHED,
  36 Index: linux-sles11/drivers/s390/cio/qdio_main.c
  37 ===================================================================
  38 --- linux-sles11.orig/drivers/s390/cio/qdio_main.c
  39 +++ linux-sles11/drivers/s390/cio/qdio_main.c
  40 @@ -851,6 +851,12 @@ static void __qdio_outbound_processing(s
  41         if (queue_type(q) == QDIO_IQDIO_QFMT && !multicast_outbound(q))
  42                 return;
  43
  44 +       if ((queue_type(q) == QDIO_IQDIO_QFMT) &&
  45 +           (atomic_read(&q->nr_buf_used)) > QDIO_IQDIO_POLL_LVL) {
  46 +               tasklet_schedule(&q->tasklet);
  47 +               return;
  48 +       }
  49 +
  50         if (q->u.out.pci_out_enabled)
  51                 return;
  52