aboutsummaryrefslogtreecommitdiff
path: root/trace/control.c
diff options
context:
space:
mode:
authorLluís Vilanova <vilanova@ac.upc.edu>2014-05-27 15:02:14 +0200
committerStefan Hajnoczi <stefanha@redhat.com>2014-06-09 15:43:40 +0200
commit5b808275f3bbe8cc95bb9301f4d5a41331d0e0e6 (patch)
treed5611a010851864336448529088cd94a9afcf83a /trace/control.c
parent82432638ebeedda8a2e18838b6fbef4b14a94f31 (diff)
trace: Multi-backend tracing
Adds support to compile QEMU with multiple tracing backends at the same time. For example, you can compile QEMU with: $ ./configure --enable-trace-backends=ftrace,dtrace Where 'ftrace' can be handy for having an in-flight record of events, and 'dtrace' can be later used to extract more information from the system. This patch allows having both available without recompiling QEMU. Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'trace/control.c')
-rw-r--r--trace/control.c49
1 files changed, 47 insertions, 2 deletions
diff --git a/trace/control.c b/trace/control.c
index 4aa02cf2d6..45e6604ec9 100644
--- a/trace/control.c
+++ b/trace/control.c
@@ -1,13 +1,19 @@
/*
* Interface for configuring and controlling the state of tracing events.
*
- * Copyright (C) 2011-2012 Lluís Vilanova <vilanova@ac.upc.edu>
+ * Copyright (C) 2011-2014 Lluís Vilanova <vilanova@ac.upc.edu>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include "trace/control.h"
+#ifdef CONFIG_TRACE_SIMPLE
+#include "trace/simple.h"
+#endif
+#ifdef CONFIG_TRACE_FTRACE
+#include "trace/ftrace.h"
+#endif
TraceEvent *trace_event_name(const char *name)
@@ -79,7 +85,20 @@ TraceEvent *trace_event_pattern(const char *pat, TraceEvent *ev)
return NULL;
}
-void trace_backend_init_events(const char *fname)
+void trace_print_events(FILE *stream, fprintf_function stream_printf)
+{
+ TraceEventID i;
+
+ for (i = 0; i < trace_event_count(); i++) {
+ TraceEvent *ev = trace_event_id(i);
+ stream_printf(stream, "%s [Event ID %u] : state %u\n",
+ trace_event_get_name(ev), i,
+ trace_event_get_state_static(ev) &&
+ trace_event_get_state_dynamic(ev));
+ }
+}
+
+static void trace_init_events(const char *fname)
{
if (fname == NULL) {
return;
@@ -130,3 +149,29 @@ void trace_backend_init_events(const char *fname)
exit(1);
}
}
+
+bool trace_init_backends(const char *events, const char *file)
+{
+#ifdef CONFIG_TRACE_SIMPLE
+ if (!st_init(file)) {
+ fprintf(stderr, "failed to initialize simple tracing backend.\n");
+ return false;
+ }
+#else
+ if (file) {
+ fprintf(stderr, "error: -trace file=...: "
+ "option not supported by the selected tracing backends\n");
+ return false;
+ }
+#endif
+
+#ifdef CONFIG_TRACE_FTRACE
+ if (!ftrace_init()) {
+ fprintf(stderr, "failed to initialize ftrace backend.\n");
+ return false;
+ }
+#endif
+
+ trace_init_events(events);
+ return true;
+}