The patch below does not apply to the 3.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From 0d0f660d882c1c02748ced13966a2413aa5d6cc2 Mon Sep 17 00:00:00 2001
From: Nicholas Bellinger <[email protected]>
Date: Sun, 5 Oct 2014 02:13:03 -0700
Subject: [PATCH] iser-target: Disable TX completion interrupt coalescing

This patch explicitly disables TX completion interrupt coalescing logic
in isert_put_response() and isert_put_datain() that was originally added
as an efficiency optimization in commit 95b60f07.

It has been reported that this change can trigger ABORT_TASK timeouts
under certain small block workloads, where disabling coalescing was
required for stability.  According to Sagi, this doesn't impact
overall performance, so go ahead and disable it for now.

Reported-by: Moussa Ba <[email protected]>
Reported-by: Sagi Grimberg <[email protected]>
Cc: <[email protected]> # 3.13+
Signed-off-by: Nicholas Bellinger <[email protected]>

diff --git a/drivers/infiniband/ulp/isert/ib_isert.c 
b/drivers/infiniband/ulp/isert/ib_isert.c
index 40969b683fdd..f7191128b725 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -2183,7 +2183,7 @@ isert_put_response(struct iscsi_conn *conn, struct 
iscsi_cmd *cmd)
                isert_cmd->tx_desc.num_sge = 2;
        }
 
-       isert_init_send_wr(isert_conn, isert_cmd, send_wr, true);
+       isert_init_send_wr(isert_conn, isert_cmd, send_wr, false);
 
        pr_debug("Posting SCSI Response IB_WR_SEND >>>>>>>>>>>>>>>>>>>>>>\n");
 
@@ -2882,7 +2882,7 @@ isert_put_datain(struct iscsi_conn *conn, struct 
iscsi_cmd *cmd)
                                     &isert_cmd->tx_desc.iscsi_header);
                isert_init_tx_hdrs(isert_conn, &isert_cmd->tx_desc);
                isert_init_send_wr(isert_conn, isert_cmd,
-                                  &isert_cmd->tx_desc.send_wr, true);
+                                  &isert_cmd->tx_desc.send_wr, false);
                isert_cmd->rdma_wr.s_send_wr.next = &isert_cmd->tx_desc.send_wr;
                wr->send_wr_num += 1;
        }

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