[SCSI] cxgb3i: fix cpu use abuse during writes
When doing a lot (128) of large writes (256K) we can hit the cxgb3_snd_win
check pretty easily. The driver's xmit thread then takes 100% of the cpu.
The driver should not be returning -EAGAIN for this problem. It should
be returing -ENOBUFS, then when the window is opened again it should
queue the xmit thread (it already wakes the xmit thread).
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/scsi/cxgb3i/cxgb3i_pdu.c b/drivers/scsi/cxgb3i/cxgb3i_pdu.c
index 7eebc9a..7091050 100644
--- a/drivers/scsi/cxgb3i/cxgb3i_pdu.c
+++ b/drivers/scsi/cxgb3i/cxgb3i_pdu.c
@@ -400,17 +400,18 @@
return 0;
}
- if (err < 0 && err != -EAGAIN) {
- kfree_skb(skb);
- cxgb3i_tx_debug("itt 0x%x, skb 0x%p, len %u/%u, xmit err %d.\n",
- task->itt, skb, skb->len, skb->data_len, err);
- iscsi_conn_printk(KERN_ERR, task->conn, "xmit err %d.\n", err);
- iscsi_conn_failure(task->conn, ISCSI_ERR_XMIT_FAILED);
+ if (err == -EAGAIN || err == -ENOBUFS) {
+ /* reset skb to send when we are called again */
+ tdata->skb = skb;
return err;
}
- /* reset skb to send when we are called again */
- tdata->skb = skb;
- return -EAGAIN;
+
+ kfree_skb(skb);
+ cxgb3i_tx_debug("itt 0x%x, skb 0x%p, len %u/%u, xmit err %d.\n",
+ task->itt, skb, skb->len, skb->data_len, err);
+ iscsi_conn_printk(KERN_ERR, task->conn, "xmit err %d.\n", err);
+ iscsi_conn_failure(task->conn, ISCSI_ERR_XMIT_FAILED);
+ return err;
}
int cxgb3i_pdu_init(void)