[PATCH] IB: Optimize canceling a MAD

Optimize canceling a MAD.
- Eliminate searching timeout list in cancel case.
- Remove duplicate calls to queue work item.
- Eliminate resending a MAD before MAD is completed.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Hal Rosenstock <halr@voltaire.com>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 13 insertions, 8 deletions

diff --git a/drivers/infiniband/core/mad.c b/drivers/infiniband/core/mad.c
index 7af72d4ae6c8..1d8f26f54ec9 100644
--- a/drivers/infiniband/core/mad.c
+++ b/drivers/infiniband/core/mad.c
@@ -1754,14 +1754,18 @@ static void wait_for_response(struct ib_mad_send_wr_private *mad_send_wr)
         delay = mad_send_wr->timeout;
         mad_send_wr->timeout += jiffies;
 
-        list_for_each_prev(list_item, &mad_agent_priv->wait_list) {
-                temp_mad_send_wr = list_entry(list_item,
-                                              struct ib_mad_send_wr_private,
-                                              agent_list);
-                if (time_after(mad_send_wr->timeout,
-                               temp_mad_send_wr->timeout))
-                        break;
+        if (delay) {
+                list_for_each_prev(list_item, &mad_agent_priv->wait_list) {
+                        temp_mad_send_wr = list_entry(list_item,
+                                                struct ib_mad_send_wr_private,
+                                                agent_list);
+                        if (time_after(mad_send_wr->timeout,
+                                       temp_mad_send_wr->timeout))
+                                break;
+                }
         }
+        else
+                list_item = &mad_agent_priv->wait_list;
         list_add(&mad_send_wr->agent_list, list_item);
 
         /* Reschedule a work item if we have a shorter timeout */
@@ -2197,7 +2201,8 @@ static void timeout_sends(void *data)
                 }
 
                 list_del(&mad_send_wr->agent_list);
-                if (!retry_send(mad_send_wr))
+                if (mad_send_wr->status == IB_WC_SUCCESS &&
+                    !retry_send(mad_send_wr))
                         continue;
 
                 spin_unlock_irqrestore(&mad_agent_priv->lock, flags);