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authorLluís <xscript@gmx.net>2011-08-31 20:31:51 +0200
committerStefan Hajnoczi <stefanha@linux.vnet.ibm.com>2011-09-01 10:34:54 +0100
commit9a82b6a590bd7c845ab9754b34b33ffee982ccb2 (patch)
treec23b7078b7db55c798577eb28f281873a5d2062c
parent03727e6a06087dc8f46d5674b4b29262bf7377a4 (diff)
trace: [stderr] add support for dynamically enabling/disabling events
Uses the generic interface provided in "trace/control.h" in order to provide a programmatic interface as well as command line and monitor controls. Signed-off-by: Fabien Chouteau <chouteau@adacore.com> Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
-rw-r--r--Makefile.objs2
-rwxr-xr-xconfigure1
-rw-r--r--docs/tracing.txt5
-rw-r--r--qemu-options.hx3
-rwxr-xr-xscripts/tracetool33
-rw-r--r--trace/stderr.c37
-rw-r--r--trace/stderr.h11
7 files changed, 81 insertions, 11 deletions
diff --git a/Makefile.objs b/Makefile.objs
index 036a4eb6ab..26b885bfeb 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -384,6 +384,8 @@ trace-nested-$(CONFIG_TRACE_DEFAULT) += default.o
trace-nested-$(CONFIG_TRACE_SIMPLE) += simple.o
trace-obj-$(CONFIG_TRACE_SIMPLE) += qemu-timer-common.o
+trace-nested-$(CONFIG_TRACE_STDERR) += stderr.o
+
trace-nested-y += control.o
trace-obj-y += $(addprefix trace/, $(trace-nested-y))
diff --git a/configure b/configure
index 4f9b27ced4..300d34bd32 100755
--- a/configure
+++ b/configure
@@ -3078,6 +3078,7 @@ if test "$trace_backend" = "simple"; then
fi
if test "$trace_backend" = "stderr"; then
echo "CONFIG_TRACE_STDERR=y" >> $config_host_mak
+ trace_default=no
fi
if test "$trace_backend" = "ust"; then
echo "CONFIG_TRACE_UST=y" >> $config_host_mak
diff --git a/docs/tracing.txt b/docs/tracing.txt
index d1d4e8cba2..4b27ab0c2a 100644
--- a/docs/tracing.txt
+++ b/docs/tracing.txt
@@ -178,11 +178,6 @@ effectively turns trace events into debug printfs.
This is the simplest backend and can be used together with existing code that
uses DPRINTF().
-Note that with this backend trace events cannot be programmatically
-enabled/disabled. Thus, in order to trim down the amount of output and the
-performance impact of tracing, you might want to add the "disable" property in
-the "trace-events" file for those events you are not interested in.
-
=== Simpletrace ===
The "simple" backend supports common use cases and comes as part of the QEMU
diff --git a/qemu-options.hx b/qemu-options.hx
index edd181bb8e..f672365e42 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -2454,7 +2454,8 @@ Immediately enable events listed in @var{file}.
The file must contain one event name (as listed in the @var{trace-events} file)
per line.
-This option is only available when using the @var{simple} tracing backend.
+This option is only available when using the @var{simple} and @var{stderr}
+tracing backends.
@item file=@var{file}
Log output traces to @var{file}.
diff --git a/scripts/tracetool b/scripts/tracetool
index c740080ebb..743d246289 100755
--- a/scripts/tracetool
+++ b/scripts/tracetool
@@ -241,7 +241,12 @@ linetoh_begin_stderr()
{
cat <<EOF
#include <stdio.h>
+#include "trace/stderr.h"
+
+extern TraceEvent trace_list[];
EOF
+
+ stderr_event_num=0
}
linetoh_stderr()
@@ -260,29 +265,47 @@ linetoh_stderr()
cat <<EOF
static inline void trace_$name($args)
{
- fprintf(stderr, "$name $fmt\n" $argnames);
+ if (trace_list[$stderr_event_num].state != 0) {
+ fprintf(stderr, "$name $fmt\n" $argnames);
+ }
}
EOF
+ stderr_event_num=$((stderr_event_num + 1))
+
}
linetoh_end_stderr()
{
-return
+ cat <<EOF
+#define NR_TRACE_EVENTS $stderr_event_num
+EOF
}
linetoc_begin_stderr()
{
-return
+ cat <<EOF
+#include "trace.h"
+
+TraceEvent trace_list[] = {
+EOF
+ stderr_event_num=0
}
linetoc_stderr()
{
-return
+ local name
+ name=$(get_name "$1")
+ cat <<EOF
+{.tp_name = "$name", .state=0},
+EOF
+ stderr_event_num=$(($stderr_event_num + 1))
}
linetoc_end_stderr()
{
-return
+ cat <<EOF
+};
+EOF
}
#END OF STDERR
diff --git a/trace/stderr.c b/trace/stderr.c
new file mode 100644
index 0000000000..7107c4a131
--- /dev/null
+++ b/trace/stderr.c
@@ -0,0 +1,37 @@
+#include "trace.h"
+#include "trace/control.h"
+
+
+void trace_print_events(FILE *stream, fprintf_function stream_printf)
+{
+ unsigned int i;
+
+ for (i = 0; i < NR_TRACE_EVENTS; i++) {
+ stream_printf(stream, "%s [Event ID %u] : state %u\n",
+ trace_list[i].tp_name, i, trace_list[i].state);
+ }
+}
+
+bool trace_event_set_state(const char *name, bool state)
+{
+ unsigned int i;
+
+ for (i = 0; i < NR_TRACE_EVENTS; i++) {
+ if (!strcmp(trace_list[i].tp_name, name)) {
+ trace_list[i].state = state;
+ return true;
+ }
+ }
+ return false;
+}
+
+bool trace_backend_init(const char *events, const char *file)
+{
+ if (file) {
+ fprintf(stderr, "error: -trace file=...: "
+ "option not supported by the selected tracing backend\n");
+ return false;
+ }
+ trace_backend_init_events(events);
+ return true;
+}
diff --git a/trace/stderr.h b/trace/stderr.h
new file mode 100644
index 0000000000..d575b613e3
--- /dev/null
+++ b/trace/stderr.h
@@ -0,0 +1,11 @@
+#ifndef TRACE_STDERR_H
+#define TRACE_STDERR_H
+
+typedef uint64_t TraceEventID;
+
+typedef struct {
+ const char *tp_name;
+ bool state;
+} TraceEvent;
+
+#endif /* ! TRACE_STDERR_H */