Change force_subbuffer switch to be per trace

[ust.git] / libust / tracectl.c

diff --git a/libust/tracectl.c b/libust/tracectl.c
index 0cff6fda9f035e8a009232268530e8e39e206ab4..463edb6b492897546a84cf3161c07c680a12eb10 100644 (file)
--- a/libust/tracectl.c
+++ b/libust/tracectl.c
@@ -558,14 +558,30 @@ static void listener_cleanup(void *ptr)
        pthread_mutex_unlock(&listen_sock_mutex);
 }
 
-static void force_subbuf_switch()
+static int force_subbuf_switch(const char *trace_name)
 {
-       struct ust_buffer *buf;
+       struct ust_trace *trace;
+       int i, j, retval = 0;
+
+       ltt_lock_traces();
+       trace = _ltt_trace_find(trace_name);
+       if (!trace) {
+                retval = -ENODATA;
+                DBG("Cannot find trace. It was likely destroyed by the user.");
+                goto unlock_traces;
+        }
 
-       cds_list_for_each_entry(buf, &open_buffers_list,
-                           open_buffers_list) {
-               ltt_force_switch(buf, FORCE_FLUSH);
+       for (i = 0; i < trace->nr_channels; i++) {
+               for (j = 0; j < trace->channels[i].n_cpus; j++) {
+                       ltt_force_switch(trace->channels[i].buf[j],
+                                        FORCE_FLUSH);
+               }
        }
+
+unlock_traces:
+       ltt_unlock_traces();
+
+       return retval;
 }
 
 /* Simple commands are those which need only respond with a return value. */
@@ -585,12 +601,6 @@ static int process_simple_client_cmd(int command, char *recv_buf)
                return setenv("UST_DAEMON_SOCKET", sock_msg->field, 1);
        }
 
-       case FORCE_SUBBUF_SWITCH:
-               /* FIXME: return codes? */
-               force_subbuf_switch();
-
-               break;
-
        default:
                return -EINVAL;
        }
@@ -716,6 +726,15 @@ static int process_trace_cmd(int command, char *trace_name)
                        return result;
                }
                return 0;
+       case FORCE_SUBBUF_SWITCH:
+               DBG("force switch");
+
+               result = force_subbuf_switch(trace_name);
+               if (result < 0) {
+                       ERR("force_subbuf_switch failed");
+                       return result;
+               }
+               return 0;
        }
 
        return 0;
@@ -1048,6 +1067,7 @@ static void process_client_cmd(struct ustcomm_header *recv_header,
        case START_TRACE:
        case STOP_TRACE:
        case DESTROY_TRACE:
+       case FORCE_SUBBUF_SWITCH:
        {
                struct ustcomm_single_field *trace_inf =
                        (struct ustcomm_single_field *)recv_buf;
@@ -1697,6 +1717,7 @@ void ust_before_fork(ust_fork_info_t *fork_info)
         * Hold listen_sock_mutex to protect from listen_sock teardown.
         */
        pthread_mutex_lock(&listen_sock_mutex);
+       rcu_bp_before_fork();
 }
 
 /* Don't call this function directly in a traced program */
@@ -1717,24 +1738,20 @@ static void ust_after_fork_common(ust_fork_info_t *fork_info)
 
 void ust_after_fork_parent(ust_fork_info_t *fork_info)
 {
+       rcu_bp_after_fork_parent();
        /* Release mutexes and reenable signals */
        ust_after_fork_common(fork_info);
 }
 
 void ust_after_fork_child(ust_fork_info_t *fork_info)
 {
-       /* First sanitize the child */
+       /* Release urcu mutexes */
+       rcu_bp_after_fork_child();
+
+       /* Sanitize the child */
        ust_fork();
 
        /* Then release mutexes and reenable signals */
        ust_after_fork_common(fork_info);
-
-       /*
-        * Make sure we clean up the urcu-bp thread list in the child by running
-        * the garbage collection before any pthread_create can be called.
-        * Failure to do so could lead to a deadlock caused by reuse of a thread
-        * ID before urcu-bp garbage collection is performed.
-        */
-       synchronize_rcu();
 }