iothread: include id in thread name

This makes it easier to find the desired thread.  Use "IO" plus the id;
even with the 14 character limit on the thread name, enough of the id should
be readable (e.g. "IO iothreadNNN" with three characters for the number).
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Message-id: 1448372804-5034-1-git-send-email-pbonzini@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

iothread.c

@@ -72,6 +72,7 @@ static void iothread_complete(UserCreatable *obj, Error **errp)
 {
     Error *local_error = NULL;
     IOThread *iothread = IOTHREAD(obj);
+    char *name, *thread_name;
 
     iothread->stopping = false;
     iothread->thread_id = -1;
@@ -87,8 +88,12 @@ static void iothread_complete(UserCreatable *obj, Error **errp)
     /* This assumes we are called from a thread with useful CPU affinity for us
      * to inherit.
      */
-    qemu_thread_create(&iothread->thread, "iothread", iothread_run,
+    name = object_get_canonical_path_component(OBJECT(obj));
+    thread_name = g_strdup_printf("IO %s", name);
+    qemu_thread_create(&iothread->thread, thread_name, iothread_run,
                        iothread, QEMU_THREAD_JOINABLE);
+    g_free(thread_name);
+    g_free(name);
 
     /* Wait for initialization to complete */
     qemu_mutex_lock(&iothread->init_done_lock);