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[Qemu-devel] [PATCH v7 12/13] trace-state: [stderr] add support for dyna
From: |
Lluís |
Subject: |
[Qemu-devel] [PATCH v7 12/13] trace-state: [stderr] add support for dynamically enabling/disabling events |
Date: |
Thu, 25 Aug 2011 21:18:49 +0200 |
User-agent: |
StGit/0.15 |
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 <address@hidden>
Signed-off-by: Lluís Vilanova <address@hidden>
---
configure | 3 +++
docs/tracing.txt | 5 -----
qemu-options.hx | 3 ++-
scripts/tracetool | 33 ++++++++++++++++++++++++++++-----
trace/stderr.c | 20 ++++++++++++++++----
trace/stderr.h | 11 +++++++++++
6 files changed, 60 insertions(+), 15 deletions(-)
create mode 100644 trace/stderr.h
diff --git a/configure b/configure
index c49c080..623d40f 100755
--- a/configure
+++ b/configure
@@ -3071,6 +3071,9 @@ fi
if test "$trace_backend" = "simple"; then
echo "CONFIG_TRACE_SIMPLE=y" >> $config_host_mak
fi
+if test "$trace_backend" = "stderr"; then
+ echo "CONFIG_TRACE_STDERR=y" >> $config_host_mak
+fi
# Set the appropriate trace file.
if test "$trace_backend" = "simple"; then
trace_file="\"$trace_file-\" FMT_pid"
diff --git a/docs/tracing.txt b/docs/tracing.txt
index 448fdef..f14dbe3 100644
--- a/docs/tracing.txt
+++ b/docs/tracing.txt
@@ -164,11 +164,6 @@ effectively turns trace events into debug printfs.
This is the simplest backend and can be used together with existing code that
uses DPRINTF().
-Note that with this backend trace events cannot be programmatically
-enabled/disabled. Thus, in order to trim down the amount of output and the
-performance impact of tracing, you might want to add the "disable" property in
-the "trace-events" file for those events you are not interested in.
-
=== Simpletrace ===
The "simple" backend supports common use cases and comes as part of the QEMU
diff --git a/qemu-options.hx b/qemu-options.hx
index 91144d9..455f1ef 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -2450,7 +2450,8 @@ Immediately enable events listed in @var{file}.
The file must contain one event name (as listed in the @var{trace-events} file)
per line.
-This option is only available when using the @var{simple} tracing backend.
+This option is only available when using the @var{simple} and @var{stderr}
+tracing backends.
@item address@hidden
Log output traces to @var{file}.
diff --git a/scripts/tracetool b/scripts/tracetool
index c740080..743d246 100755
--- a/scripts/tracetool
+++ b/scripts/tracetool
@@ -241,7 +241,12 @@ linetoh_begin_stderr()
{
cat <<EOF
#include <stdio.h>
+#include "trace/stderr.h"
+
+extern TraceEvent trace_list[];
EOF
+
+ stderr_event_num=0
}
linetoh_stderr()
@@ -260,29 +265,47 @@ linetoh_stderr()
cat <<EOF
static inline void trace_$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
index 480a6b7..61debfa 100644
--- a/trace/stderr.c
+++ b/trace/stderr.c
@@ -1,21 +1,33 @@
+#include "trace.h"
#include "trace/control.h"
void trace_print_events (FILE *stream, fprintf_function stream_printf)
{
- fprintf(stderr, "qemu: warning: cannot print the trace events with the
current backend\n");
- stream_printf(stream, "error: operation not supported with the current
backend\n");
+ 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)
{
- fprintf(stderr, "qemu: warning: cannot set the state of a trace event with
the current backend\n");
+ 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_config_init (void)
{
- return false;
+ return true;
}
bool trace_config_init_file (const char *file)
diff --git a/trace/stderr.h b/trace/stderr.h
new file mode 100644
index 0000000..d575b61
--- /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 */
- [Qemu-devel] [PATCH v7 02/13] trace: [configure] rename CONFIG_*_TRACE into CONFIG_TRACE_*, (continued)
- [Qemu-devel] [PATCH v7 02/13] trace: [configure] rename CONFIG_*_TRACE into CONFIG_TRACE_*, Lluís, 2011/08/25
- [Qemu-devel] [PATCH v7 03/13] trace: [make] replace 'ifeq' with values in CONFIG_TRACE_*, Lluís, 2011/08/25
- [Qemu-devel] [PATCH v7 04/13] trace: move backend-specific code into the trace/ directory, Lluís, 2011/08/25
- [Qemu-devel] [PATCH v7 05/13] trace: avoid conditional code compilation during option parsing, Lluís, 2011/08/25
- [Qemu-devel] [PATCH v7 06/13] trace: generalize the "property" concept in the trace-events file, Lluís, 2011/08/25
- [Qemu-devel] [PATCH v7 11/13] trace-state: [simple] disable all trace points by default, Lluís, 2011/08/25
- [Qemu-devel] [PATCH v7 12/13] trace-state: [stderr] add support for dynamically enabling/disabling events,
Lluís <=
- [Qemu-devel] [PATCH v7 13/13] trace: enable all events, Lluís, 2011/08/25
- [Qemu-devel] [PATCH v7 08/13] trace-state: always compile support for controlling and querying trace event states, Lluís, 2011/08/25
- [Qemu-devel] [PATCH v7 09/13] trace-state: add "-trace events" argument to control initial state, Lluís, 2011/08/25
- [Qemu-devel] [PATCH v7 07/13] trace-state: separate trace event control and query routines from the simple backend, Lluís, 2011/08/25
- [Qemu-devel] [PATCH v7 10/13] trace-state: always use the "nop" backend on events with the "disable" keyword, Lluís, 2011/08/25
- Re: [Qemu-devel] [PATCH v7 00/13] trace-state: make the behaviour of "disable" consistent across all backends, Stefan Hajnoczi, 2011/08/31
- Re: [Qemu-devel] [PATCH v7 00/13] trace-state: make the behaviour of "disable" consistent across all backends, Stefan Hajnoczi, 2011/08/31