[PATCH -tip 3/7] perf bts: Introduce new sub command 'perf bts trace'

Akihiro Nagai
2010-12-03T04:01:02Z

Introduce new sub command 'perf bts trace'.
This command can parse and print bts log recorded by
'perf bts record'.

Usage:
- First, record the bts log 'perf bts record <command>'
- Second, parse and print bts log 'perf bts trace'

Output:
0xffffffff8146fe0e => 0x0000003806200b20
0x0000003806200b23 => 0x0000003806204910
0xffffffff8146fe0e => 0x0000003806204910
0xffffffff8146fe0e => 0x0000003806204936
0xffffffff8146fe0e => 0x000000380620493d
0x0000003806204981 => 0x00000038062049a3
0x00000038062049a7 => 0x0000003806204988
...

Signed-off-by: Akihiro Nagai <akihiro.nagai.hw@hitachi.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: linux-kernel@vger.kernel.org
---

tools/perf/Documentation/perf-bts.txt | 14 ++++++--
tools/perf/builtin-bts.c | 59 +++++++++++++++++++++++++++++++--
2 files changed, 67 insertions(+), 6 deletions(-)

diff --git a/tools/perf/Documentation/perf-bts.txt b/tools/perf/Documentation/perf-bts.txt
index 55a2fe6..5920dcc 100644
--- a/tools/perf/Documentation/perf-bts.txt
+++ b/tools/perf/Documentation/perf-bts.txt
@@ -3,22 +3,30 @@ perf-bts(1)

NAME
----
-perf-bts - Record branch-trace-store log
+perf-bts - Record and print branch-trace-store log

SYNOPSIS
--------
[verse]
-'perf bts' record <command>
+'perf bts' [<options>] {record|trace}

DESCRIPTION
-----------
-This command can record branch-trace-store log.
+This command can record and print branch-trace-store log.
Branch-trace-store is a facility of processors. It can record
address of branch to/from on every branch instruction and interrupt.

'perf bts record <command>' records branch-trace-store log while specified
command is executing. And, save to the file "perf.data".

+'perf bts trace' parses recorded branch-trace-store log and prints it.
+
+OPTIONS
+-------
+-i::
+--input=::
+ Specify input file name to analyze.
+
SEE ALSO
--------
linkperf:perf-record[1]
diff --git a/tools/perf/builtin-bts.c b/tools/perf/builtin-bts.c
index 587cfad..54e83af 100644
--- a/tools/perf/builtin-bts.c
+++ b/tools/perf/builtin-bts.c
@@ -1,10 +1,25 @@
#include "builtin.h"
#include "perf.h"
#include "util/parse-options.h"
+#include "util/session.h"
+#include "util/cache.h"
+#include <inttypes.h>
+
+/* format string of specifying min width to print address */
+#if __WORDSIZE == 32
+#define FMT_ADDR_WIDTH "10" /* length of "0x" + 32bit address */
+#else
+#define FMT_ADDR_WIDTH "18" /* length of "0x" + 64bit address */
+#endif
+/* format string to print address */
+#define FMT_ADDR "%#0" FMT_ADDR_WIDTH "llx"
+
+/* default input file name to analyze */
+static const char *input_name = "perf.data";

static const char * const bts_usage[] = {
- "perf bts record <command>",
- NULL,
+ "perf bts [<options>] {record|trace}",
+ NULL
};

/* arguments to call 'perf record' */
@@ -16,11 +31,45 @@ static const char * const record_args[] = {
"-d",
};

-/* dummy struct option to call parse_options() */
static const struct option bts_options[] = {
+ OPT_STRING('i', "input", &input_name, "file", "input file name"),
OPT_END()
};

+static int process_sample_event(event_t *event, struct perf_session *session)
+{
+ struct sample_data data;
+
+ memset(&data, 0, sizeof(data));
+ event__parse_sample(event, session->sample_type, &data);
+
+ /* data.ip is 'from address', data.addr is 'to address' */
+ printf(FMT_ADDR " => " FMT_ADDR "\n", data.ip, data.addr);
+
+ return 0;
+}
+
+static struct perf_event_ops event_ops = {
+ .sample = process_sample_event,
+ .ordered_samples = false,
+};
+
+static int __cmd_trace(void)
+{
+ struct perf_session *session;
+
+ session = perf_session__new(input_name, O_RDONLY, 0, false);
+ if (!session) {
+ fprintf(stderr, "failed to create perf_session.\n");
+ return -ENOMEM;
+ }
+
+ perf_session__process_events(session, &event_ops);
+ perf_session__delete(session);
+
+ return 0;
+}
+
static int __cmd_record(int argc, const char **argv)
{
unsigned int rec_argc, i, j;
@@ -55,6 +104,10 @@ int cmd_bts(int argc, const char **argv, const char *prefix __used)

if (!strncmp(argv[0], "record", 6))
return __cmd_record(argc, argv);
+ else if (!strncmp(argv[0], "trace", 5)) {
+ setup_pager();
+ return __cmd_trace();
+ }
else
usage_with_options(bts_usage, bts_options);