Unblock the SIGALRM so that hung I/O can be killed for each thread.

src/slurmctld/agent.c

@@ -127,6 +127,8 @@ typedef struct queued_request {
 	time_t       last_attempt;	/* Time of last xmit attempt */
 } queued_request_t;
 
+static int agent_sigarray[] = { SIGALRM, 0 };
+
 static void _alarm_handler(int dummy);
 static inline void _comm_err(char *node_name);
 static void _list_delete_retry(void *retry_entry);
@@ -169,6 +171,7 @@ void *agent(void *args)
 		goto cleanup;
 
 	xsignal(SIGALRM, _alarm_handler);
+	xsignal_unblock(agent_sigarray);
 
 	/* initialize the agent data structures */
 	agent_info_ptr = _make_agent_info(agent_arg_ptr);
@@ -590,7 +593,6 @@ static void *_thread_per_node_rpc(void *args)
 	thread_ptr->state = DSH_ACTIVE;
 	slurm_mutex_unlock(task_ptr->thread_mutex_ptr);
 
-
 	/* send request message */
 	msg.address  = thread_ptr->slurm_addr;
 	msg.msg_type = msg_type;
@@ -689,7 +691,7 @@ static void *_thread_per_node_rpc(void *args)
 }
 
 /*
- * SIGALRM handler.  We are really interested in interrupting hung communictions 
+ * SIGALRM handler.  We are really interested in interrupting hung communictions
  * and causing them to return EINTR. Multiple interupts might be required.
  */
 static void _alarm_handler(int dummy)
@@ -697,7 +699,6 @@ static void _alarm_handler(int dummy)
 	xsignal(SIGALRM, _alarm_handler);
 }
 
-
 /*
  * _queue_agent_retry - Queue any failed RPCs for later replay
  * IN agent_info_ptr - pointer to info on completed agent requests