On Mon, Apr 4, 2011 at 10:49 PM, Lluís <xscr...@gmx.net> wrote:
> When using the "simple" tracing backend, all events are in disabled state by
> default.
>
> The "-trace events" argument can be used to provide a file with a list of
> trace
> event names that will be enabled prior to starting execution. This saves the
> user from manually toggling event states through the monitor interface, as
> well
> as enables early tracing for the selected points, much like other
> more-sophisticated backends like "ust" or "dtrace".
>
> Signed-off-by: Lluís Vilanova <vilan...@ac.upc.edu>
> ---
> docs/tracing.txt | 5 +++
> qemu-config.c | 5 ++-
> qemu-options.hx | 18 ++++++++--
> vl.c | 94
> +++++++++++++++++++++++++++++++++++-------------------
> 4 files changed, 84 insertions(+), 38 deletions(-)
Too many whitespace/indentation changes here. If you want to fix
whitespace then please do it in a separate patch that is not part of
this series.
> @@ -2833,9 +2834,10 @@ int main(int argc, char **argv, char **envp)
> break;
> #ifdef CONFIG_SIMPLE_TRACE
> case QEMU_OPTION_trace:
> - opts = qemu_opts_parse(qemu_find_opts("trace"), optarg, 0);
> + opts = qemu_opts_parse(qemu_find_opts("trace"), optarg, 1);
Previously "qemu -trace asdf" failed:
qemu: -trace asdf: Invalid parameter 'asdf'
Please don't add an implied file= since there are no legacy users whom
this would help. Let's strictly accept file= and events=.
> @@ -2887,6 +2889,32 @@ int main(int argc, char **argv, char **envp)
> if (!st_init(trace_file)) {
> fprintf(stderr, "warning: unable to initialize simple trace
> backend\n");
> }
> + if (trace_events_file) {
> + FILE *trace_events_fp = fopen(trace_events_file, "r");
> + if (!trace_events_fp) {
> + fprintf(stderr, "could not open trace events file '%s': %s\n",
> + trace_events_file, strerror(errno));
> + exit(1);
> + }
> + char line_buf[1024];
> + char *line;
> + for (line = fgets(line_buf, 1024, trace_events_fp); line != NULL;
> + line = fgets(line_buf, 1024, trace_events_fp)) {
Without the line variable, hardcoded 1024, and duplicated fgets() call:
while (fgets(line_buf, sizeof(line_buf), trace_events_fp)) {
> + int len = strlen(line);
There's no reason to cast the size_t return value to int here.
> + if (len > 1) { /* skip empty lines */
> + line[len - 1] = '\0';
> + if (!st_change_trace_event_state(line, true)) {
The build breaks when --enable-trace-backend != simple because this
code is outside an #ifdef CONFIG_SIMPLE_TRACE. Please add this:
diff --git a/simpletrace.h b/simpletrace.h
index 8d893bd..5d9d2ec 100644
--- a/simpletrace.h
+++ b/simpletrace.h
@@ -43,6 +43,11 @@ static inline bool st_init(const char *file)
{
return true;
}
+
+static bool st_change_trace_event_state(const char *tname, bool tstate)
+{
+ return true;
+}
#endif /* !CONFIG_SIMPLE_TRACE */
#endif /* SIMPLETRACE_H */
