perf trace: Clarify that -e is about syscalls, not perf events in general
This comes from the desire of having -e/--expr to have the same meaning
as for 'strace', while other perf tools use it for --event, which
'trace' honours, i.e. all perf tools have --event in common, but trace
uses -e for strace's --expr.
Clarify it in the --help output.
Reported-by: David Ahern <dsahern@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-5j94bcsdmcbeu2xthnzsj60d@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 23fb081..d1139b6 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -2660,8 +2660,7 @@
OPT_BOOLEAN(0, "comm", &trace.show_comm,
"show the thread COMM next to its id"),
OPT_BOOLEAN(0, "tool_stats", &trace.show_tool_stats, "show tool stats"),
- OPT_STRING('e', "expr", &ev_qualifier_str, "expr",
- "list of events to trace"),
+ OPT_STRING('e', "expr", &ev_qualifier_str, "expr", "list of syscalls to trace"),
OPT_STRING('o', "output", &output_name, "file", "output file name"),
OPT_STRING('i', "input", &input_name, "file", "Analyze events in file"),
OPT_STRING('p', "pid", &trace.opts.target.pid, "pid",