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Commit 0aab2136 authored by Wang Nan's avatar Wang Nan Committed by Arnaldo Carvalho de Melo
Browse files

perf record: Add --dry-run option to check cmdline options 



With '--dry-run', 'perf record' doesn't do reall recording. Combine with
llvm.dump-obj option, --dry-run can be used to help compile BPF objects
for embedded platform.

Signed-off-by: default avatarWang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1466064161-48553-3-git-send-email-wangnan0@huawei.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent f0784649

tools/perf/Documentation/perf-record.txt

+7 −0
Original line number Diff line number Diff line
@@ -360,6 +360,13 @@ particular perf.data snapshot should be kept or not. 


Implies --timestamp-filename, --no-buildid and --no-buildid-cache.



--dry-run::

Parse options then exit. --dry-run can be used to detect errors in cmdline

options.



'perf record --dry-run -e' can act as a BPF script compiler if llvm.dump-obj

in config file is set to true.



SEE ALSO

--------

linkperf:perf-stat[1], linkperf:perf-list[1]

tools/perf/builtin-record.c

+7 −0
Original line number Diff line number Diff line
@@ -1274,6 +1274,8 @@ static struct record record = { 
const char record_callchain_help[] = CALLCHAIN_RECORD_HELP

	"\n\t\t\t\tDefault: fp";



static bool dry_run;



/*

 * XXX Will stay a global variable till we fix builtin-script.c to stop messing

 * with it and switch to use the library functions in perf_evlist that came
@@ -1393,6 +1395,8 @@ struct option __record_options[] = { 
		    "append timestamp to output filename"),

	OPT_BOOLEAN(0, "switch-output", &record.switch_output,

		    "Switch output when receive SIGUSR2"),

	OPT_BOOLEAN(0, "dry-run", &dry_run,

		    "Parse options then exit"),

	OPT_END()

};
@@ -1462,6 +1466,9 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused) 
	if (err)

		return err;



	if (dry_run)

		return 0;



	err = bpf__setup_stdout(rec->evlist);

	if (err) {

		bpf__strerror_setup_stdout(rec->evlist, err, errbuf, sizeof(errbuf));