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

Masami Hiramatsu
2010-12-06T03:10:45Z

(2010/12/03 12:59), Akihiro Nagai wrote:
> 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>

It looks a good step.

Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@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);
>
>
> --
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--
Masami HIRAMATSU
2nd Dept. Linux Technology Center
Hitachi, Ltd., Systems Development Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com