[PATCH 3/8] perf record: Add --block option

[Jiri Olsa <jolsa@kernel.org>]

Adding --block option to allow record command set block
bool in struct perf_event_attr for event, like:

  # perf record -e raw_syscalls:sys_enter --block ls
  # perf record -e raw_syscalls:sys_enter --block -p ...

It's allowed only for syscall tracepoint events
attached to process.

Link: http://lkml.kernel.org/n/tip-ocz7zwwkkx11v0mkxrtcddih@git.kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 tools/perf/builtin-record.c | 9 +++++++++
 tools/perf/perf.h           | 1 +
 tools/perf/util/evsel.c     | 3 +++
 3 files changed, 13 insertions(+)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 4736dc96c4ca..79c8d2f94f86 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1937,6 +1937,8 @@ static struct option __record_options[] = {
 		    "append timestamp to output filename"),
 	OPT_BOOLEAN(0, "timestamp-boundary", &record.timestamp_boundary,
 		    "Record timestamp boundary (time of first/last samples)"),
+	OPT_BOOLEAN(0, "block", &record.opts.block,
+		    "Request blocked tracing (for syscall tracepoints)"),
 	OPT_STRING_OPTARG_SET(0, "switch-output", &record.switch_output.str,
 			  &record.switch_output.set, "signal,size,time",
 			  "Switch output when receive SIGUSR2 or cross size,time threshold",
@@ -2116,6 +2118,13 @@ int cmd_record(int argc, const char **argv)
 		goto out;
 	}
 
+	if (rec->opts.block &&
+	    !target__has_task(&rec->opts.target) &&
+	    !target__none(&rec->opts.target)) {
+		pr_err("Can't use --block on non task targets\n");
+		goto out;
+	}
+
 	/* Enable ignoring missing threads when -u/-p option is defined. */
 	rec->opts.ignore_missing_thread = rec->opts.target.uid != UINT_MAX || rec->opts.target.pid;
 
diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index 4d40baa45a5f..7884701247b8 100644
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -66,6 +66,7 @@ struct record_opts {
 	bool	     ignore_missing_thread;
 	bool	     strict_freq;
 	bool	     sample_id;
+	bool	     block;
 	unsigned int freq;
 	unsigned int mmap_pages;
 	unsigned int auxtrace_mmap_pages;
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index dbc0466db368..e4943e8f811b 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1045,6 +1045,9 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts,
 	if (opts->sample_transaction)
 		perf_evsel__set_sample_bit(evsel, TRANSACTION);
 
+	if (opts->block)
+		attr->block = true;
+
 	if (opts->running_time) {
 		evsel->attr.read_format |=
 			PERF_FORMAT_TOTAL_TIME_ENABLED |
-- 
2.17.2