perf trace: Allow configuring if the syscall duration should be printed

  # perf config trace.show_duration=no
  # perf config -l | grep trace
  trace.default_events=/home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o
  trace.show_zeros=true
  trace.show_duration=no
  # trace -e *sleep sleep 1
     0.000 sleep/8729 nanosleep(rqtp: 0x7ffcb0b4c940, rmtp: 0) = 0
  # perf config trace.show_duration=yes
  # trace -e *sleep sleep 1
     0.000 (1000.212 ms): sleep/8735 nanosleep(rqtp: 0x7ffca15fa770, rmtp: 0) = 0
  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-2c7h1m8fhzb9puxtj9nlevi8@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Documentation/perf-config.txt

@@ -528,6 +528,10 @@ trace.*::
 		The initial use case is to add augmented_raw_syscalls.o to
 		activate the 'perf trace' logic that looks for syscall
 		pointer contents after the normal tracepoint payload.
+
+	trace.show_duration::
+		Show syscall duration.
+
 	trace.show_zeros::
 		Do not suppress syscall arguments that are equal to zero.
 

tools/perf/builtin-trace.c

@@ -127,6 +127,7 @@ struct trace {
 	bool			show_tool_stats;
 	bool			trace_syscalls;
 	bool			kernel_syscallchains;
+	bool			show_duration;
 	bool			show_zeros;
 	bool			force;
 	bool			vfs_getname;
@@ -1215,7 +1216,8 @@ static size_t trace__fprintf_entry_head(struct trace *trace, struct thread *thre
 					u64 duration, bool duration_calculated, u64 tstamp, FILE *fp)
 {
 	size_t printed = trace__fprintf_tstamp(trace, tstamp, fp);
-	printed += fprintf_duration(duration, duration_calculated, fp);
+	if (trace->show_duration)
+		printed += fprintf_duration(duration, duration_calculated, fp);
 	return printed + trace__fprintf_comm_tid(trace, thread, fp);
 }
 
@@ -2190,7 +2192,7 @@ static int trace__event_handler(struct trace *trace, struct perf_evsel *evsel,
 	trace__printf_interrupted_entry(trace);
 	trace__fprintf_tstamp(trace, sample->time, trace->output);
 
-	if (trace->trace_syscalls)
+	if (trace->trace_syscalls && trace->show_duration)
 		fprintf(trace->output, "(         ): ");
 
 	if (thread)
@@ -3536,6 +3538,8 @@ static int trace__config(const char *var, const char *value, void *arg)
 					       "event selector. use 'perf list' to list available events",
 					       parse_events_option);
 		err = parse_events_option(&o, value, 0);
+	} else if (!strcmp(var, "trace.show_duration")) {
+		trace->show_duration = perf_config_bool(var, value);
 	} else if (!strcmp(var, "trace.show_zeros")) {
 		trace->show_zeros = perf_config_bool(var, value);
 	}
@@ -3568,6 +3572,7 @@ int cmd_trace(int argc, const char **argv)
 		},
 		.output = stderr,
 		.show_comm = true,
+		.show_duration = true,
 		.trace_syscalls = false,
 		.kernel_syscallchains = false,
 		.max_stack = UINT_MAX,