src/patches/suse-2.6.27.31/patches.fixes/block-optimizations-in-blk_rq_timed_out_timer

   1 Subject: block: optimizations in blk_rq_timed_out_timer()
   2 From: malahal@us.ibm.com <malahal@us.ibm.com>
   3 Date: Mon Dec 29 08:28:42 2008 +0100:
   4 Git: 565e411d764eeda006738dfadbccca79d48381e1
   5 References: bnc#464155
   6
   7 Now the rq->deadline can't be zero if the request is in the
   8 timeout_list, so there is no need to have next_set. There is no need to
   9 access a request's deadline field if blk_rq_timed_out is called on it.
  10
  11 Signed-off-by: Malahal Naineni <malahal@us.ibm.com>
  12 Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
  13 Signed-off-by: Hannes Reinecke <hare@suse.de>
  14
  15 ---
  16  block/blk-timeout.c |   10 ++++------
  17  1 file changed, 4 insertions(+), 6 deletions(-)
  18
  19 --- a/block/blk-timeout.c
  20 +++ b/block/blk-timeout.c
  21 @@ -48,7 +48,7 @@ static void blk_rq_timed_out(struct requ
  22  void blk_rq_timed_out_timer(unsigned long data)
  23  {
  24         struct request_queue *q = (struct request_queue *) data;
  25 -       unsigned long flags, uninitialized_var(next), next_set = 0;
  26 +       unsigned long flags, next = 0;
  27         struct request *rq, *tmp;
  28
  29         spin_lock_irqsave(q->queue_lock, flags);
  30 @@ -63,12 +63,10 @@ void blk_rq_timed_out_timer(unsigned lon
  31                         if (blk_mark_rq_complete(rq))
  32                                 continue;
  33                         blk_rq_timed_out(rq);
  34 +               } else {
  35 +                       if (!next || time_after(next, rq->deadline))
  36 +                               next = rq->deadline;
  37                 }
  38 -               if (!next_set) {
  39 -                       next = rq->deadline;
  40 -                       next_set = 1;
  41 -               } else if (time_after(next, rq->deadline))
  42 -                       next = rq->deadline;
  43         }
  44
  45         if (next_set && !list_empty(&q->timeout_list))