[tip:perf/core] perf trace: Support --events foo: bar --no-syscalls

[tip-bot for Arnaldo Carvalho de Melo]

Commit-ID:  726f3234dd125633438922a07a80f933f13daf82
Gitweb:     http://git.kernel.org/tip/726f3234dd125633438922a07a80f933f13daf82
Author:     Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
AuthorDate: Fri, 6 Feb 2015 10:16:45 +0100
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Fri, 13 Feb 2015 17:30:29 -0300

perf trace: Support --events foo:bar --no-syscalls

I.e. support tracing just tracepoints, without strace like
raw_syscalls:*.

[acme@ssdandy linux]$ trace --no-sys --ev sched:*exec,sched:*switch,sched:*exit usleep 1
  0.048 (     ): sched:sched_process_exec:filename=/usr/bin/usleep pid=27298 old_pid=27298)
  0.369 (     ): sched:sched_switch:usleep:27298 [120] S ==> swapper/5:0 [120])
  0.452 (     ): sched:sched_process_exit:comm=usleep pid=27298 prio=120)
[acme@ssdandy linux]$

TODO: remove that (...) thing when --no-syscalls is specified.

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Don Zickus <dzickus@xxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-vn0hsixsbhm31b2rpj97r96k@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/builtin-trace.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index a44ac93..b1c1df9 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -2625,7 +2625,8 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
 	if (trace.summary_only)
 		trace.summary = trace.summary_only;
 
-	if (!trace.trace_syscalls && !trace.trace_pgfaults) {
+	if (!trace.trace_syscalls && !trace.trace_pgfaults &&
+	    trace.evlist->nr_entries == 0 /* Was --events used? */) {
 		pr_err("Please specify something to trace.\n");
 		return -1;
 	}
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/