rtla: Refactor save_trace_to_file

The functions osnoise_hist_main(), osnoise_top_main(),
timerlat_hist_main(), and timerlat_top_main() are lengthy and contain
duplicated code.

Refactor by consolidating the duplicate lines into the
save_trace_to_file() function.

Cc: Daniel Bristot de Oliveira <[email protected]>
Cc: John Kacur <[email protected]>
Cc: "Luis Claudio R. Goncalves" <[email protected]>
Cc: Eder Zulian <[email protected]>
Cc: Dan Carpenter <[email protected]>
Cc: Gabriele Monaco <[email protected]>
Link: https://lore.kernel.org/[email protected]
Signed-off-by: Costa Shulyupin <[email protected]>
Reviewed-by: Tomas Glozar <[email protected]>
Tested-by: Tomas Glozar <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

Author: makelinux

tools/tracing/rtla/src/osnoise_hist.c

@@ -983,10 +983,7 @@ int osnoise_hist_main(int argc, char *argv[])
 
 	if (osnoise_trace_is_off(tool, record)) {
 		printf("rtla osnoise hit stop tracing\n");
-		if (params->trace_output) {
-			printf("  Saving trace to %s\n", params->trace_output);
-			save_trace_to_file(record->trace.inst, params->trace_output);
-		}
+		save_trace_to_file(record->trace.inst, params->trace_output);
 	}
 
 out_hist:

tools/tracing/rtla/src/osnoise_top.c

@@ -813,10 +813,7 @@ int osnoise_top_main(int argc, char **argv)
 
 	if (osnoise_trace_is_off(tool, record)) {
 		printf("osnoise hit stop tracing\n");
-		if (params->trace_output) {
-			printf("  Saving trace to %s\n", params->trace_output);
-			save_trace_to_file(record->trace.inst, params->trace_output);
-		}
+		save_trace_to_file(record->trace.inst, params->trace_output);
 	}
 
 out_top:

tools/tracing/rtla/src/timerlat_hist.c

@@ -1473,10 +1473,7 @@ int timerlat_hist_main(int argc, char *argv[])
 		if (!params->no_aa)
 			timerlat_auto_analysis(params->stop_us, params->stop_total_us);
 
-		if (params->trace_output) {
-			printf("  Saving trace to %s\n", params->trace_output);
-			save_trace_to_file(record->trace.inst, params->trace_output);
-		}
+		save_trace_to_file(record->trace.inst, params->trace_output);
 	}
 
 out_hist:

tools/tracing/rtla/src/timerlat_top.c

@@ -1295,10 +1295,7 @@ int timerlat_top_main(int argc, char *argv[])
 		if (!params->no_aa)
 			timerlat_auto_analysis(params->stop_us, params->stop_total_us);
 
-		if (params->trace_output) {
-			printf("  Saving trace to %s\n", params->trace_output);
-			save_trace_to_file(record->trace.inst, params->trace_output);
-		}
+		save_trace_to_file(record->trace.inst, params->trace_output);
 	} else if (params->aa_only) {
 		/*
 		 * If the trace did not stop with --aa-only, at least print the

tools/tracing/rtla/src/trace.c

@@ -75,12 +75,16 @@ int save_trace_to_file(struct tracefs_instance *inst, const char *filename)
 	int out_fd, in_fd;
 	int retval = -1;
 
+	if (!filename)
+		return 0;
+
 	in_fd = tracefs_instance_file_open(inst, file, O_RDONLY);
 	if (in_fd < 0) {
 		err_msg("Failed to open trace file\n");
 		return -1;
 	}
 
+	printf("  Saving trace to %s\n", filename);
 	out_fd = creat(filename, mode);
 	if (out_fd < 0) {
 		err_msg("Failed to create output file %s\n", filename);