[PATCH 0/2] perf: Remove trace_find_next_event()

[PATCH 0/2] perf: Remove trace_find_next_event()

[Steven Rostedt]

The trace_find_next_event() is buggy and useless. Open code the current
users (it's not much work), and nuke the function.

Steven Rostedt (VMware) (2):
      perf: Iterate on tep event arrays directly
      perf: Remove unused trace_find_next_event()

----
 .../perf/util/scripting-engines/trace-event-perl.c |  8 ++++--
 .../util/scripting-engines/trace-event-python.c    |  9 +++++--
 tools/perf/util/trace-event-parse.c                | 31 ----------------------
 tools/perf/util/trace-event.h                      |  2 --
 4 files changed, 13 insertions(+), 37 deletions(-)

[PATCH 1/2] perf: Iterate on tep event arrays directly

[Steven Rostedt]

From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

Instead of calling a useless (and broken) helper function to get the next
event of a tep event array, just get the array directly and iterate over it.

Note, the broken part was from trace_find_next_event() which after this will
no longer be used, and can be removed.

Link: http://lkml.kernel.org/r/20191017153733.630cd5eb@gandalf.local.home

Reported-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 tools/perf/util/scripting-engines/trace-event-perl.c   | 8 ++++++--
 tools/perf/util/scripting-engines/trace-event-python.c | 9 +++++++--
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/scripting-engines/trace-event-perl.c b/tools/perf/util/scripting-engines/trace-event-perl.c
index 15961854ba67..741f040648b5 100644
--- a/tools/perf/util/scripting-engines/trace-event-perl.c
+++ b/tools/perf/util/scripting-engines/trace-event-perl.c
@@ -539,10 +539,11 @@ static int perl_stop_script(void)
 
 static int perl_generate_script(struct tep_handle *pevent, const char *outfile)
 {
+	int i, not_first, count, nr_events;
+	struct tep_event **all_events;
 	struct tep_event *event = NULL;
 	struct tep_format_field *f;
 	char fname[PATH_MAX];
-	int not_first, count;
 	FILE *ofp;
 
 	sprintf(fname, "%s.pl", outfile);
@@ -603,8 +604,11 @@ sub print_backtrace\n\
 }\n\n\
 ");
 
+	nr_events = tep_get_events_count(pevent);
+	all_events = tep_list_events(pevent, TEP_EVENT_SORT_ID);
 
-	while ((event = trace_find_next_event(pevent, event))) {
+	for (i = 0; all_events && i < nr_events; i++) {
+		event = all_events[i];
 		fprintf(ofp, "sub %s::%s\n{\n", event->system, event->name);
 		fprintf(ofp, "\tmy (");
 
diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c
index 5d341efc3237..93c03b39cd9c 100644
--- a/tools/perf/util/scripting-engines/trace-event-python.c
+++ b/tools/perf/util/scripting-engines/trace-event-python.c
@@ -1687,10 +1687,11 @@ static int python_stop_script(void)
 
 static int python_generate_script(struct tep_handle *pevent, const char *outfile)
 {
+	int i, not_first, count, nr_events;
+	struct tep_event **all_events;
 	struct tep_event *event = NULL;
 	struct tep_format_field *f;
 	char fname[PATH_MAX];
-	int not_first, count;
 	FILE *ofp;
 
 	sprintf(fname, "%s.py", outfile);
@@ -1735,7 +1736,11 @@ static int python_generate_script(struct tep_handle *pevent, const char *outfile
 	fprintf(ofp, "def trace_end():\n");
 	fprintf(ofp, "\tprint(\"in trace_end\")\n\n");
 
-	while ((event = trace_find_next_event(pevent, event))) {
+	nr_events = tep_get_events_count(pevent);
+	all_events = tep_list_events(pevent, TEP_EVENT_SORT_ID);
+
+	for (i = 0; all_events && i < nr_events; i++) {
+		event = all_events[i];
 		fprintf(ofp, "def %s__%s(", event->system, event->name);
 		fprintf(ofp, "event_name, ");
 		fprintf(ofp, "context, ");
-- 
2.23.0

[PATCH 2/2] perf: Remove unused trace_find_next_event()

[Steven Rostedt]

From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

trace_find_next_event() was buggy and pretty much a useless helper. As there
are no more users, just remove it.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 tools/perf/util/trace-event-parse.c | 31 -----------------------------
 tools/perf/util/trace-event.h       |  2 --
 2 files changed, 33 deletions(-)

diff --git a/tools/perf/util/trace-event-parse.c b/tools/perf/util/trace-event-parse.c
index 5d6bfc70b210..9634f0ae57be 100644
--- a/tools/perf/util/trace-event-parse.c
+++ b/tools/perf/util/trace-event-parse.c
@@ -173,37 +173,6 @@ int parse_event_file(struct tep_handle *pevent,
 	return tep_parse_event(pevent, buf, size, sys);
 }
 
-struct tep_event *trace_find_next_event(struct tep_handle *pevent,
-					struct tep_event *event)
-{
-	static int idx;
-	int events_count;
-	struct tep_event *all_events;
-
-	all_events = tep_get_first_event(pevent);
-	events_count = tep_get_events_count(pevent);
-	if (!pevent || !all_events || events_count < 1)
-		return NULL;
-
-	if (!event) {
-		idx = 0;
-		return all_events;
-	}
-
-	if (idx < events_count && event == (all_events + idx)) {
-		idx++;
-		if (idx == events_count)
-			return NULL;
-		return (all_events + idx);
-	}
-
-	for (idx = 1; idx < events_count; idx++) {
-		if (event == (all_events + (idx - 1)))
-			return (all_events + idx);
-	}
-	return NULL;
-}
-
 struct flag {
 	const char *name;
 	unsigned long long value;
diff --git a/tools/perf/util/trace-event.h b/tools/perf/util/trace-event.h
index 2e158387b3d7..72fdf2a3577c 100644
--- a/tools/perf/util/trace-event.h
+++ b/tools/perf/util/trace-event.h
@@ -47,8 +47,6 @@ void parse_saved_cmdline(struct tep_handle *pevent, char *file, unsigned int siz
 
 ssize_t trace_report(int fd, struct trace_event *tevent, bool repipe);
 
-struct tep_event *trace_find_next_event(struct tep_handle *pevent,
-					struct tep_event *event);
 unsigned long long read_size(struct tep_event *event, void *ptr, int size);
 unsigned long long eval_flag(const char *flag);
 
-- 
2.23.0

Re: [PATCH 1/2] perf: Iterate on tep event arrays directly

[Arnaldo Carvalho de Melo]

Em Thu, Oct 17, 2019 at 05:05:22PM -0400, Steven Rostedt escreveu:
> From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
> 
> Instead of calling a useless (and broken) helper function to get the next
> event of a tep event array, just get the array directly and iterate over it.
> 
> Note, the broken part was from trace_find_next_event() which after this will
> no longer be used, and can be removed.
> 
> Link: http://lkml.kernel.org/r/20191017153733.630cd5eb@gandalf.local.home

I'll add a:

Fixes: bb3dd7e7c4d5 ("tools lib traceevent, perf tools: Move struct tep_handler definition in a local header file")
Cc: stable@vger.kernel.org : v4.20+

As this is when this problem starts causing the segfault when generating
python scripts from perf.data files with multiple tracepoint events, ok?

- Arnaldo
 
> Reported-by: Daniel Bristot de Oliveira <bristot@redhat.com>
> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
> ---
>  tools/perf/util/scripting-engines/trace-event-perl.c   | 8 ++++++--
>  tools/perf/util/scripting-engines/trace-event-python.c | 9 +++++++--
>  2 files changed, 13 insertions(+), 4 deletions(-)
> 
> diff --git a/tools/perf/util/scripting-engines/trace-event-perl.c b/tools/perf/util/scripting-engines/trace-event-perl.c
> index 15961854ba67..741f040648b5 100644
> --- a/tools/perf/util/scripting-engines/trace-event-perl.c
> +++ b/tools/perf/util/scripting-engines/trace-event-perl.c
> @@ -539,10 +539,11 @@ static int perl_stop_script(void)
>  
>  static int perl_generate_script(struct tep_handle *pevent, const char *outfile)
>  {
> +	int i, not_first, count, nr_events;
> +	struct tep_event **all_events;
>  	struct tep_event *event = NULL;
>  	struct tep_format_field *f;
>  	char fname[PATH_MAX];
> -	int not_first, count;
>  	FILE *ofp;
>  
>  	sprintf(fname, "%s.pl", outfile);
> @@ -603,8 +604,11 @@ sub print_backtrace\n\
>  }\n\n\
>  ");
>  
> +	nr_events = tep_get_events_count(pevent);
> +	all_events = tep_list_events(pevent, TEP_EVENT_SORT_ID);
>  
> -	while ((event = trace_find_next_event(pevent, event))) {
> +	for (i = 0; all_events && i < nr_events; i++) {
> +		event = all_events[i];
>  		fprintf(ofp, "sub %s::%s\n{\n", event->system, event->name);
>  		fprintf(ofp, "\tmy (");
>  
> diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c
> index 5d341efc3237..93c03b39cd9c 100644
> --- a/tools/perf/util/scripting-engines/trace-event-python.c
> +++ b/tools/perf/util/scripting-engines/trace-event-python.c
> @@ -1687,10 +1687,11 @@ static int python_stop_script(void)
>  
>  static int python_generate_script(struct tep_handle *pevent, const char *outfile)
>  {
> +	int i, not_first, count, nr_events;
> +	struct tep_event **all_events;
>  	struct tep_event *event = NULL;
>  	struct tep_format_field *f;
>  	char fname[PATH_MAX];
> -	int not_first, count;
>  	FILE *ofp;
>  
>  	sprintf(fname, "%s.py", outfile);
> @@ -1735,7 +1736,11 @@ static int python_generate_script(struct tep_handle *pevent, const char *outfile
>  	fprintf(ofp, "def trace_end():\n");
>  	fprintf(ofp, "\tprint(\"in trace_end\")\n\n");
>  
> -	while ((event = trace_find_next_event(pevent, event))) {
> +	nr_events = tep_get_events_count(pevent);
> +	all_events = tep_list_events(pevent, TEP_EVENT_SORT_ID);
> +
> +	for (i = 0; all_events && i < nr_events; i++) {
> +		event = all_events[i];
>  		fprintf(ofp, "def %s__%s(", event->system, event->name);
>  		fprintf(ofp, "event_name, ");
>  		fprintf(ofp, "context, ");
> -- 
> 2.23.0
> 

-- 

- Arnaldo

Re: [PATCH 1/2] perf: Iterate on tep event arrays directly

[Steven Rostedt]

On Thu, 17 Oct 2019 18:24:31 -0300
Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com> wrote:

> I'll add a:
> 
> Fixes: bb3dd7e7c4d5 ("tools lib traceevent, perf tools: Move struct tep_handler definition in a local header file")
> Cc: stable@vger.kernel.org : v4.20+
> 
> As this is when this problem starts causing the segfault when generating
> python scripts from perf.data files with multiple tracepoint events, ok?

Sure, go ahead. I realized I forgot to add a Fixes tag when sending it.

-- Steve

Re: [PATCH 1/2] perf: Iterate on tep event arrays directly

[Arnaldo Carvalho de Melo]

Em Thu, Oct 17, 2019 at 05:28:23PM -0400, Steven Rostedt escreveu:
> On Thu, 17 Oct 2019 18:24:31 -0300
> Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com> wrote:
> 
> > I'll add a:
> > 
> > Fixes: bb3dd7e7c4d5 ("tools lib traceevent, perf tools: Move struct tep_handler definition in a local header file")
> > Cc: stable@vger.kernel.org : v4.20+
> > 
> > As this is when this problem starts causing the segfault when generating
> > python scripts from perf.data files with multiple tracepoint events, ok?
> 
> Sure, go ahead. I realized I forgot to add a Fixes tag when sending it.

np, I added it, thanks for the prompt fix!

- Arnaldo

[tip: perf/core] perf tools: Remove unused trace_find_next_event()

[tip-bot2 for Steven Rostedt (VMware)]

The following commit has been merged into the perf/core branch of tip:

Commit-ID:     9bdff5b6436655d42dd30253c521e86ce07b9961
Gitweb:        https://git.kernel.org/tip/9bdff5b6436655d42dd30253c521e86ce07b9961
Author:        Steven Rostedt (VMware) <rostedt@goodmis.org>
AuthorDate:    Thu, 17 Oct 2019 17:05:23 -04:00
Committer:     Arnaldo Carvalho de Melo <acme@redhat.com>
CommitterDate: Fri, 18 Oct 2019 12:07:46 -03:00

perf tools: Remove unused trace_find_next_event()

trace_find_next_event() was buggy and pretty much a useless helper. As
there are no more users, just remove it.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Tzvetomir Stoyanov <tstoyanov@vmware.com>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20191017210636.224045576@goodmis.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/trace-event-parse.c | 31 +----------------------------
 tools/perf/util/trace-event.h       |  2 +--
 2 files changed, 33 deletions(-)

diff --git a/tools/perf/util/trace-event-parse.c b/tools/perf/util/trace-event-parse.c
index 5d6bfc7..9634f0a 100644
--- a/tools/perf/util/trace-event-parse.c
+++ b/tools/perf/util/trace-event-parse.c
@@ -173,37 +173,6 @@ int parse_event_file(struct tep_handle *pevent,
 	return tep_parse_event(pevent, buf, size, sys);
 }
 
-struct tep_event *trace_find_next_event(struct tep_handle *pevent,
-					struct tep_event *event)
-{
-	static int idx;
-	int events_count;
-	struct tep_event *all_events;
-
-	all_events = tep_get_first_event(pevent);
-	events_count = tep_get_events_count(pevent);
-	if (!pevent || !all_events || events_count < 1)
-		return NULL;
-
-	if (!event) {
-		idx = 0;
-		return all_events;
-	}
-
-	if (idx < events_count && event == (all_events + idx)) {
-		idx++;
-		if (idx == events_count)
-			return NULL;
-		return (all_events + idx);
-	}
-
-	for (idx = 1; idx < events_count; idx++) {
-		if (event == (all_events + (idx - 1)))
-			return (all_events + idx);
-	}
-	return NULL;
-}
-
 struct flag {
 	const char *name;
 	unsigned long long value;
diff --git a/tools/perf/util/trace-event.h b/tools/perf/util/trace-event.h
index 2e15838..72fdf2a 100644
--- a/tools/perf/util/trace-event.h
+++ b/tools/perf/util/trace-event.h
@@ -47,8 +47,6 @@ void parse_saved_cmdline(struct tep_handle *pevent, char *file, unsigned int siz
 
 ssize_t trace_report(int fd, struct trace_event *tevent, bool repipe);
 
-struct tep_event *trace_find_next_event(struct tep_handle *pevent,
-					struct tep_event *event);
 unsigned long long read_size(struct tep_event *event, void *ptr, int size);
 unsigned long long eval_flag(const char *flag);
 

[tip: perf/urgent] perf tools: Remove unused trace_find_next_event()

[tip-bot2 for Steven Rostedt (VMware)]

The following commit has been merged into the perf/urgent branch of tip:

Commit-ID:     6047e1a81e9fe9851ed37e13c2438312c04435d9
Gitweb:        https://git.kernel.org/tip/6047e1a81e9fe9851ed37e13c2438312c04435d9
Author:        Steven Rostedt (VMware) <rostedt@goodmis.org>
AuthorDate:    Thu, 17 Oct 2019 17:05:23 -04:00
Committer:     Arnaldo Carvalho de Melo <acme@redhat.com>
CommitterDate: Tue, 05 Nov 2019 08:39:27 -03:00

perf tools: Remove unused trace_find_next_event()

trace_find_next_event() was buggy and pretty much a useless helper. As
there are no more users, just remove it.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Tzvetomir Stoyanov <tstoyanov@vmware.com>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20191017210636.224045576@goodmis.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/trace-event-parse.c | 31 +----------------------------
 tools/perf/util/trace-event.h       |  2 +--
 2 files changed, 33 deletions(-)

diff --git a/tools/perf/util/trace-event-parse.c b/tools/perf/util/trace-event-parse.c
index 5d6bfc7..9634f0a 100644
--- a/tools/perf/util/trace-event-parse.c
+++ b/tools/perf/util/trace-event-parse.c
@@ -173,37 +173,6 @@ int parse_event_file(struct tep_handle *pevent,
 	return tep_parse_event(pevent, buf, size, sys);
 }
 
-struct tep_event *trace_find_next_event(struct tep_handle *pevent,
-					struct tep_event *event)
-{
-	static int idx;
-	int events_count;
-	struct tep_event *all_events;
-
-	all_events = tep_get_first_event(pevent);
-	events_count = tep_get_events_count(pevent);
-	if (!pevent || !all_events || events_count < 1)
-		return NULL;
-
-	if (!event) {
-		idx = 0;
-		return all_events;
-	}
-
-	if (idx < events_count && event == (all_events + idx)) {
-		idx++;
-		if (idx == events_count)
-			return NULL;
-		return (all_events + idx);
-	}
-
-	for (idx = 1; idx < events_count; idx++) {
-		if (event == (all_events + (idx - 1)))
-			return (all_events + idx);
-	}
-	return NULL;
-}
-
 struct flag {
 	const char *name;
 	unsigned long long value;
diff --git a/tools/perf/util/trace-event.h b/tools/perf/util/trace-event.h
index 2e15838..72fdf2a 100644
--- a/tools/perf/util/trace-event.h
+++ b/tools/perf/util/trace-event.h
@@ -47,8 +47,6 @@ void parse_saved_cmdline(struct tep_handle *pevent, char *file, unsigned int siz
 
 ssize_t trace_report(int fd, struct trace_event *tevent, bool repipe);
 
-struct tep_event *trace_find_next_event(struct tep_handle *pevent,
-					struct tep_event *event);
 unsigned long long read_size(struct tep_event *event, void *ptr, int size);
 unsigned long long eval_flag(const char *flag);