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Date: Mon, 03 May 2010 00:51:01 -0500
From: Tom Zanussi <tzanussi@...il.com>
To: Arnaldo Carvalho de Melo <acme@...stprotocols.net>
Cc: Ingo Molnar <mingo@...e.hu>, linux-kernel@...r.kernel.org,
Arnaldo Carvalho de Melo <acme@...hat.com>,
Frédéric Weisbecker <fweisbec@...il.com>,
Mike Galbraith <efault@....de>,
Paul Mackerras <paulus@...ba.org>,
Peter Zijlstra <a.p.zijlstra@...llo.nl>
Subject: Re: [PATCH 4/5] perf record: Don't exit in live mode when no
tracepoints are enabled
Hi,
On Sun, 2010-05-02 at 19:59 -0300, Arnaldo Carvalho de Melo wrote:
> From: Arnaldo Carvalho de Melo <acme@...hat.com>
>
> With this I was able to actually test Tom Zanussi's two previous patches
> in my usual perf testing ways, i.e. without any tracepoints activated.
>
> Cc: Frédéric Weisbecker <fweisbec@...il.com>
> Cc: Mike Galbraith <efault@....de>
> Cc: Paul Mackerras <paulus@...ba.org>
> Cc: Peter Zijlstra <a.p.zijlstra@...llo.nl>
> Cc: Tom Zanussi <tzanussi@...il.com>
> LKML-Reference: <new-submission>
> Signed-off-by: Arnaldo Carvalho de Melo <acme@...hat.com>
> ---
> tools/perf/builtin-record.c | 15 +++++++++------
> 1 files changed, 9 insertions(+), 6 deletions(-)
>
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index e382d93..ac989e9 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -666,12 +666,15 @@ static int __cmd_record(int argc, const char **argv)
> nr_counters,
> process_synthesized_event,
> session);
> - if (err <= 0) {
> - pr_err("Couldn't record tracing data.\n");
> - return err;
> - }
> -
> - advance_output(err);
> + /*
> + * FIXME err <= 0 here actually means that there were no tracepoints
> + * so its not really an error, just that we don't need to synthesize
> + * anything.
> + * We really have to return this more properly and also propagate
> + * errors that now are calling die()
> + */
> + if (err > 0)
> + advance_output(err);
> }
>
> machine = perf_session__find_host_machine(session);
Thanks for taking these patches and fixing them up!
BTW, I posted a patch a couple days ago that also fixes this problem, in
response to a bug report for a non-live-mode problem seen when using
SAMPLE_RAW with no tracepoints:
http://lkml.org/lkml/2010/5/1/2
Here it is again, fixed up to apply to your tree...
Tom
From: Tom Zanussi <tzanussi@...il.com>
Date: Mon, 3 May 2010 00:14:48 -0500
Subject: [PATCH] perf: record TRACE_INFO only if using tracepoints and
SAMPLE_RAW
The current perf code implicitly assumes SAMPLE_RAW means tracepoints
are being used, but doesn't check for that. It happily records the
TRACE_INFO even if SAMPLE_RAW is used without tracepoints, but when
the perf data is read it won't go any further when it finds TRACE_INFO
but no tracepoints, and displays misleading errors.
This adds a check for both in perf-record, and won't record TRACE_INFO
unless both are true. This at least allows perf report -D to dump raw
events, and avoids triggering a misleading error condition in perf
trace. It doesn't actually enable the non-tracepoint raw events to be
displayed in perf trace, since perf trace currently only deals with
tracepoint events.
Signed-off-by: Tom Zanussi <tzanussi@...il.com>
---
tools/perf/builtin-record.c | 35
+++++++++++++++++++++--------------
tools/perf/util/header.c | 1 -
tools/perf/util/parse-events.h | 1 +
tools/perf/util/trace-event-info.c | 5 +++++
4 files changed, 27 insertions(+), 15 deletions(-)
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index ac989e9..0ff67d1 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -560,11 +560,12 @@ static int __cmd_record(int argc, const char **argv)
return err;
}
- if (raw_samples) {
+ if (raw_samples && have_tracepoints(attrs, nr_counters)) {
perf_header__set_feat(&session->header, HEADER_TRACE_INFO);
} else {
for (i = 0; i < nr_counters; i++) {
- if (attrs[i].sample_type & PERF_SAMPLE_RAW) {
+ if (attrs[i].sample_type & PERF_SAMPLE_RAW &&
+ attrs[i].type == PERF_TYPE_TRACEPOINT) {
perf_header__set_feat(&session->header, HEADER_TRACE_INFO);
break;
}
@@ -662,19 +663,25 @@ static int __cmd_record(int argc, const char **argv)
return err;
}
- err = event__synthesize_tracing_data(output, attrs,
- nr_counters,
- process_synthesized_event,
- session);
- /*
- * FIXME err <= 0 here actually means that there were no tracepoints
- * so its not really an error, just that we don't need to synthesize
- * anything.
- * We really have to return this more properly and also propagate
- * errors that now are calling die()
- */
- if (err > 0)
+ if (have_tracepoints(attrs, nr_counters)) {
+ /*
+ * FIXME err <= 0 here actually means that
+ * there were no tracepoints so its not really
+ * an error, just that we don't need to
+ * synthesize anything. We really have to
+ * return this more properly and also
+ * propagate errors that now are calling die()
+ */
+ err = event__synthesize_tracing_data(output, attrs,
+ nr_counters,
+ process_synthesized_event,
+ session);
+ if (err <= 0) {
+ pr_err("Couldn't record tracing data.\n");
+ return err;
+ }
advance_output(err);
+ }
}
machine = perf_session__find_host_machine(session);
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 79da0e5..2b9f898 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -436,7 +436,6 @@ static int perf_header__adds_write(struct perf_header *self, int fd)
trace_sec->size = lseek(fd, 0, SEEK_CUR) - trace_sec->offset;
}
-
if (perf_header__has_feat(self, HEADER_BUILD_ID)) {
struct perf_file_section *buildid_sec;
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index b8c1f64..fc4ab3f 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -13,6 +13,7 @@ struct tracepoint_path {
};
extern struct tracepoint_path *tracepoint_id_to_path(u64 config);
+extern bool have_tracepoints(struct perf_event_attr *pattrs, int nb_events);
extern int nr_counters;
diff --git a/tools/perf/util/trace-event-info.c b/tools/perf/util/trace-event-info.c
index 30cd9b5..0a1fb9d 100644
--- a/tools/perf/util/trace-event-info.c
+++ b/tools/perf/util/trace-event-info.c
@@ -487,6 +487,11 @@ get_tracepoints_path(struct perf_event_attr *pattrs, int nb_events)
return nr_tracepoints > 0 ? path.next : NULL;
}
+bool have_tracepoints(struct perf_event_attr *pattrs, int nb_events)
+{
+ return get_tracepoints_path(pattrs, nb_events) ? true : false;
+}
+
int read_tracing_data(int fd, struct perf_event_attr *pattrs, int nb_events)
{
char buf[BUFSIZ];
--
1.6.6.1
--
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