svn commit: r297406 - head/sys/ofed/drivers/infiniband/core

[Navdeep Parhar]

Author: np
Date: Wed Mar 30 01:08:08 2016
New Revision: 297406
URL: https://svnweb.freebsd.org/changeset/base/297406

Log:
  Remove unnecessary dequeue_mutex (added in r294610) from the iWARP
  connection manager.  Examining so_comp without synchronization with
  iw_so_event_handler is a harmless race.
  
  Submitted by:	Krishnamraju Eraparaju @ Chelsio
  Reviewed by:	Steve Wise @ Open Grid Computing
  Sponsored by:	Chelsio Communications

Modified:
  head/sys/ofed/drivers/infiniband/core/iwcm.c

Modified: head/sys/ofed/drivers/infiniband/core/iwcm.c
==============================================================================
--- head/sys/ofed/drivers/infiniband/core/iwcm.c	Wed Mar 30 00:44:10 2016	(r297405)
+++ head/sys/ofed/drivers/infiniband/core/iwcm.c	Wed Mar 30 01:08:08 2016	(r297406)
@@ -79,7 +79,6 @@ struct iwcm_listen_work {
 static LIST_HEAD(listen_port_list);
 
 static DEFINE_MUTEX(listen_port_mutex);
-static DEFINE_MUTEX(dequeue_mutex);
 
 struct listen_port_info {
 	struct list_head list;
@@ -455,7 +454,6 @@ iw_so_event_handler(struct work_struct *
 		kfree(work);
 		return;
 	}
-	mutex_lock(&dequeue_mutex);
 
 	/* Dequeue & process  all new 'so' connection requests for this cmid */
 	while ((so = dequeue_socket(work->cm_id->so)) != NULL) {
@@ -475,7 +473,6 @@ iw_so_event_handler(struct work_struct *
 		}
 	}
 err:
-	mutex_unlock(&dequeue_mutex);
 	kfree(work);
 #endif
 	return;
@@ -487,7 +484,6 @@ iw_so_upcall(struct socket *parent_so, v
 	struct socket *so;
 	struct iw_cm_id *cm_id = arg;
 
-	mutex_lock(&dequeue_mutex);
 	/* check whether iw_so_event_handler() already dequeued this 'so' */
 	so = TAILQ_FIRST(&parent_so->so_comp);
 	if (!so)
@@ -500,7 +496,6 @@ iw_so_upcall(struct socket *parent_so, v
 	INIT_WORK(&work->work, iw_so_event_handler);
 	queue_work(iwcm_wq, &work->work);
 
-	mutex_unlock(&dequeue_mutex);
 	return SU_OK;
 }