[PATCH 2/3] perf trace: Add option to analyze events in a file versus live

[David Ahern <dsahern@gmail.com>]

Allows capture of raw_syscall:* events and analyzed at a later
time.

Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
---
 tools/perf/Documentation/perf-trace.txt |    4 ++
 tools/perf/builtin-trace.c              |   92 ++++++++++++++++++++++++++++++-
 2 files changed, 95 insertions(+), 1 deletion(-)

diff --git a/tools/perf/Documentation/perf-trace.txt b/tools/perf/Documentation/perf-trace.txt
index fe19811..34c459b 100644
--- a/tools/perf/Documentation/perf-trace.txt
+++ b/tools/perf/Documentation/perf-trace.txt
@@ -74,6 +74,10 @@ the thread executes on the designated CPUs. Default is to monitor all CPUs.
 --sched:
 	Accrue thread runtime and provide a summary at the end of the session.
 
+-r
+--replay
+	Process events from a given perf data file.
+
 SEE ALSO
 --------
 linkperf:perf-record[1], linkperf:perf-script[1]
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index b72afc7..a0a1540 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -4,6 +4,7 @@
 #include "util/debug.h"
 #include "util/evlist.h"
 #include "util/machine.h"
+#include "util/session.h"
 #include "util/thread.h"
 #include "util/parse-options.h"
 #include "util/strlist.h"
@@ -648,6 +649,36 @@ out_dump:
 	return 0;
 }
 
+static int trace__process_sample(struct perf_tool *tool,
+				 union perf_event *event __maybe_unused,
+				 struct perf_sample *sample,
+				 struct perf_evsel *evsel,
+				 struct machine *machine __maybe_unused)
+{
+	struct trace *trace = container_of(tool, struct trace, tool);
+	int err = 0;
+
+	tracepoint_handler handler = evsel->handler.func;
+
+	if (trace->base_time == 0)
+		trace->base_time = sample->time;
+
+	if (handler)
+		handler(trace, evsel, sample);
+
+	return err;
+}
+
+static bool
+perf_session__has_tp(struct perf_session *session, const char *name)
+{
+	struct perf_evsel *evsel;
+
+	evsel = perf_evlist__find_tracepoint_by_name(session->evlist, name);
+
+	return evsel != NULL;
+}
+
 static int trace__run(struct trace *trace, int argc, const char **argv)
 {
 	struct perf_evlist *evlist = perf_evlist__new();
@@ -787,6 +818,61 @@ out:
 	return err;
 }
 
+static int trace__replay(struct trace *trace)
+{
+	const struct perf_evsel_str_handler handlers[] = {
+		{ "raw_syscalls:sys_enter",  trace__sys_enter, },
+		{ "raw_syscalls:sys_exit",   trace__sys_exit, },
+	};
+
+	struct perf_session *session;
+	int err = -1;
+
+	trace->tool.sample	  = trace__process_sample;
+	trace->tool.mmap	  = perf_event__process_mmap;
+	trace->tool.comm	  = perf_event__process_comm;
+	trace->tool.exit	  = perf_event__process_exit;
+	trace->tool.fork	  = perf_event__process_fork;
+	trace->tool.attr	  = perf_event__process_attr;
+	trace->tool.tracing_data = perf_event__process_tracing_data;
+	trace->tool.build_id	  = perf_event__process_build_id;
+
+	trace->tool.ordered_samples = true;
+	trace->tool.ordering_requires_timestamps = true;
+
+	if (symbol__init() < 0)
+		return -1;
+
+	session = perf_session__new(input_name, O_RDONLY, 0, false, &trace->tool);
+	if (session == NULL)
+		return -ENOMEM;
+
+	err = perf_session__set_tracepoints_handlers(session, handlers);
+	if (err)
+		goto out;
+
+	if (!perf_session__has_tp(session, "raw_syscalls:sys_enter")) {
+		pr_err("Data file does not have raw_syscalls:sys_enter events\n");
+		goto out;
+	}
+
+	if (!perf_session__has_tp(session, "raw_syscalls:sys_exit")) {
+		pr_err("Data file does not have raw_syscalls:sys_exit events\n");
+		goto out;
+	}
+
+	setup_pager();
+
+	err = perf_session__process_events(session, &trace->tool);
+	if (err)
+		pr_err("Failed to process events, error %d", err);
+
+out:
+	perf_session__delete(session);
+
+	return err;
+}
+
 static size_t trace__fprintf_threads_header(FILE *fp)
 {
 	size_t printed;
@@ -888,6 +974,7 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
 	OPT_STRING('e', "expr", &ev_qualifier_str, "expr",
 		    "list of events to trace"),
 	OPT_STRING('o', "output", &output_name, "file", "output file name"),
+	OPT_STRING('r', "replay", &input_name, "file", "Analyze events in file"),
 	OPT_STRING('p', "pid", &trace.opts.target.pid, "pid",
 		    "trace events on existing process id"),
 	OPT_STRING('t', "tid", &trace.opts.target.tid, "tid",
@@ -954,7 +1041,10 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
 	if (!argc && perf_target__none(&trace.opts.target))
 		trace.opts.target.system_wide = true;
 
-	err = trace__run(&trace, argc, argv);
+	if (input_name)
+		err = trace__replay(&trace);
+	else
+		err = trace__run(&trace, argc, argv);
 
 	if (trace.sched && !err)
 		trace__fprintf_thread_summary(&trace, trace.output);
-- 
1.7.10.1