svn commit: r314581 - stable/10/sys/dev/iscsi

[Alexander Motin]

Author: mav
Date: Fri Mar  3 06:03:01 2017
New Revision: 314581
URL: https://svnweb.freebsd.org/changeset/base/314581

Log:
  MFC r313851: Fix tight loop spinning on postponed requests.

Modified:
  stable/10/sys/dev/iscsi/iscsi.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/dev/iscsi/iscsi.c
==============================================================================
--- stable/10/sys/dev/iscsi/iscsi.c	Fri Mar  3 06:02:27 2017	(r314580)
+++ stable/10/sys/dev/iscsi/iscsi.c	Fri Mar  3 06:03:01 2017	(r314581)
@@ -470,15 +470,14 @@ iscsi_maintenance_thread_terminate(struc
 static void
 iscsi_maintenance_thread(void *arg)
 {
-	struct iscsi_session *is;
-
-	is = arg;
+	struct iscsi_session *is = arg;
 
+	ISCSI_SESSION_LOCK(is);
 	for (;;) {
-		ISCSI_SESSION_LOCK(is);
 		if (is->is_reconnecting == false &&
 		    is->is_terminating == false &&
-		    STAILQ_EMPTY(&is->is_postponed))
+		    (STAILQ_EMPTY(&is->is_postponed) ||
+		     ISCSI_SNGT(is->is_cmdsn, is->is_maxcmdsn)))
 			cv_wait(&is->is_maintenance_cv, &is->is_lock);
 
 		/* Terminate supersedes reconnect. */
@@ -492,12 +491,13 @@ iscsi_maintenance_thread(void *arg)
 		if (is->is_reconnecting) {
 			ISCSI_SESSION_UNLOCK(is);
 			iscsi_maintenance_thread_reconnect(is);
+			ISCSI_SESSION_LOCK(is);
 			continue;
 		}
 
 		iscsi_session_send_postponed(is);
-		ISCSI_SESSION_UNLOCK(is);
 	}
+	ISCSI_SESSION_UNLOCK(is);
 }
 
 static void