IB/mad: Report number of times a mad was retried

To allow ULPs to tune timeout values and capture retry statistics,
report the number of times that a mad send operation was retried.

For RMPP mads, report the total number of times that the any portion
(send window) of the send operation was retried.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

diff --git a/drivers/infiniband/core/mad.c b/drivers/infiniband/core/mad.c
index 649335a..5eace99 100644 (file)
--- a/drivers/infiniband/core/mad.c
+++ b/drivers/infiniband/core/mad.c
@@ -1100,7 +1100,9 @@ int ib_post_send_mad(struct ib_mad_send_buf *send_buf,
                mad_send_wr->tid = ((struct ib_mad_hdr *) send_buf->mad)->tid;
                /* Timeout will be updated after send completes */
                mad_send_wr->timeout = msecs_to_jiffies(send_buf->timeout_ms);
-               mad_send_wr->retries = send_buf->retries;
+               mad_send_wr->max_retries = send_buf->retries;
+               mad_send_wr->retries_left = send_buf->retries;
+               send_buf->retries = 0;
                /* Reference for work request to QP + response */
                mad_send_wr->refcount = 1 + (mad_send_wr->timeout > 0);
                mad_send_wr->status = IB_WC_SUCCESS;
@@ -2436,9 +2438,12 @@ static int retry_send(struct ib_mad_send_wr_private *mad_send_wr)
 {
        int ret;
 
-       if (!mad_send_wr->retries--)
+       if (!mad_send_wr->retries_left)
                return -ETIMEDOUT;
 
+       mad_send_wr->retries_left--;
+       mad_send_wr->send_buf.retries++;
+
        mad_send_wr->timeout = msecs_to_jiffies(mad_send_wr->send_buf.timeout_ms);
 
        if (mad_send_wr->mad_agent_priv->agent.rmpp_version) {

diff --git a/drivers/infiniband/core/mad_priv.h b/drivers/infiniband/core/mad_priv.h
index 9be5cc0..8b75010 100644 (file)
--- a/drivers/infiniband/core/mad_priv.h
+++ b/drivers/infiniband/core/mad_priv.h
@@ -131,7 +131,8 @@ struct ib_mad_send_wr_private {
        struct ib_sge sg_list[IB_MAD_SEND_REQ_MAX_SG];
        __be64 tid;
        unsigned long timeout;
-       int retries;
+       int max_retries;
+       int retries_left;
        int retry;
        int refcount;
        enum ib_wc_status status;

diff --git a/drivers/infiniband/core/mad_rmpp.c b/drivers/infiniband/core/mad_rmpp.c
index d43bc62..a5e2a31 100644 (file)
--- a/drivers/infiniband/core/mad_rmpp.c
+++ b/drivers/infiniband/core/mad_rmpp.c
@@ -684,7 +684,7 @@ static void process_rmpp_ack(struct ib_mad_agent_private *agent,
 
        if (seg_num > mad_send_wr->last_ack) {
                adjust_last_ack(mad_send_wr, seg_num);
-               mad_send_wr->retries = mad_send_wr->send_buf.retries;
+               mad_send_wr->retries_left = mad_send_wr->max_retries;
        }
        mad_send_wr->newwin = newwin;
        if (mad_send_wr->last_ack == mad_send_wr->send_buf.seg_count) {

diff --git a/include/rdma/ib_mad.h b/include/rdma/ib_mad.h
index 8ec3799..7228c05 100644 (file)
--- a/include/rdma/ib_mad.h
+++ b/include/rdma/ib_mad.h
@@ -230,7 +230,9 @@ struct ib_class_port_info
  * @seg_count: The number of RMPP segments allocated for this send.
  * @seg_size: Size of each RMPP segment.
  * @timeout_ms: Time to wait for a response.
- * @retries: Number of times to retry a request for a response.
+ * @retries: Number of times to retry a request for a response.  For MADs
+ *   using RMPP, this applies per window.  On completion, returns the number
+ *   of retries needed to complete the transfer.
  *
  * Users are responsible for initializing the MAD buffer itself, with the
  * exception of any RMPP header.  Additional segment buffer space allocated