perf parser: Improve error message for PMU address filters

PATCH In review Jack Henschel 4 participants 4 messages Jul 4, 2018 – Aug 23, 2018 perf events

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Jack Henschel

author

2018-07-04 12:13 UTC #0 lore raw

PATCH v2 1/1 perf parser: Improve error message for PMU address filters

This is the second version of a patch that improves the error message of the perf events parser when the PMU hardware does not support address filters.

Previously, the perf returned the following error:

Quoted 2 lines

$ perf record -e intel_pt// --filter 'filter sys_write'
--filter option should follow a -e tracepoint or HW tracer option

This implies there is some syntax error present in the command line, which is not true. Rather, notify the user that the CPU does not have support for this feature.

For example, Intel chips based on the Broadwell micro-archticture have the Intel PT PMU, but do not support address filtering.

Now, perf prints the following error message:

Quoted 2 lines

$ perf record -e intel_pt// --filter 'filter sys_write'
This CPU does not support address filtering

Signed-off-by Jack Henschel <[email protected]>

---
 tools/perf/util/parse-events.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

tools/perf/util/parse-events.c +10 ~~-10~~

index 15eec49e71a1..f8cd3e7c9186 100644
@@ -1991,8 +1991,11 @@ static int set_filter(struct perf_evsel *evsel, const void *arg)
 	int nr_addr_filters = 0;
 	struct perf_pmu *pmu = NULL;
 
-	if (evsel == NULL)
-		goto err;
+	if (evsel == NULL) {
+		fprintf(stderr,
+			"--filter option should follow a -e tracepoint or HW tracer option\n");
+		return -1;
+	}
 
 	if (evsel->attr.type == PERF_TYPE_TRACEPOINT) {
 		if (perf_evsel__append_tp_filter(evsel, str) < 0) {

@@ -2014,8 +2017,11 @@ static int set_filter(struct perf_evsel *evsel, const void *arg)
 		perf_pmu__scan_file(pmu, "nr_addr_filters",
 				    "%d", &nr_addr_filters);
 
-	if (!nr_addr_filters)
-		goto err;
+	if (!nr_addr_filters) {
+		fprintf(stderr,
+			"This CPU does not support address filtering\n");
+		return -1;
+	}
 
 	if (perf_evsel__append_addr_filter(evsel, str) < 0) {
 		fprintf(stderr,

@@ -2024,12 +2030,6 @@ static int set_filter(struct perf_evsel *evsel, const void *arg)
 	}
 
 	return 0;
-
-err:
-	fprintf(stderr,
-		"--filter option should follow a -e tracepoint or HW tracer option\n");
-
-	return -1;
 }
 
 int parse_filter(const struct option *opt, const char *str,

Signature · 1 line

2.18.0

Jiri Olsa

Acked-by on v2 1/1

2018-07-04 15:25 UTC #1 lore raw

Quoted 11 lines · Jack Henschel

This is the second version of a patch that improves the error message of the perf events parser when the PMU hardware does not support address filters.
Previously, the perf returned the following error:
Quoted 2 lines
$ perf record -e intel_pt// --filter 'filter sys_write'
--filter option should follow a -e tracepoint or HW tracer option
This implies there is some syntax error present in the command line, which is not true. Rather, notify the user that the CPU does not have support for this feature.

Quoted 8 lines

For example, Intel chips based on the Broadwell micro-archticture have the Intel PT PMU, but do not support address filtering.
Now, perf prints the following error message:
Quoted 2 lines
$ perf record -e intel_pt// --filter 'filter sys_write'
This CPU does not support address filtering
Signed-off-by Jack Henschel <[email protected]>

Acked-by Jiri Olsa <[email protected]>

thanks,
jirka

Quoted 52 lines

---
 tools/perf/util/parse-events.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

tools/perf/util/parse-events.c +10 ~~-10~~

index 15eec49e71a1..f8cd3e7c9186 100644
@@ -1991,8 +1991,11 @@ static int set_filter(struct perf_evsel *evsel, const void *arg)
 	int nr_addr_filters = 0;
 	struct perf_pmu *pmu = NULL;
 
-	if (evsel == NULL)
-		goto err;
+	if (evsel == NULL) {
+		fprintf(stderr,
+			"--filter option should follow a -e tracepoint or HW tracer option\n");
+		return -1;
+	}
 
 	if (evsel->attr.type == PERF_TYPE_TRACEPOINT) {
 		if (perf_evsel__append_tp_filter(evsel, str) < 0) {

@@ -2014,8 +2017,11 @@ static int set_filter(struct perf_evsel *evsel, const void *arg)
 		perf_pmu__scan_file(pmu, "nr_addr_filters",
 				    "%d", &nr_addr_filters);
 
-	if (!nr_addr_filters)
-		goto err;
+	if (!nr_addr_filters) {
+		fprintf(stderr,
+			"This CPU does not support address filtering\n");
+		return -1;
+	}
 
 	if (perf_evsel__append_addr_filter(evsel, str) < 0) {
 		fprintf(stderr,

@@ -2024,12 +2030,6 @@ static int set_filter(struct perf_evsel *evsel, const void *arg)
 	}
 
 	return 0;
-
-err:
-	fprintf(stderr,
-		"--filter option should follow a -e tracepoint or HW tracer option\n");
-
-	return -1;
 }
 
 int parse_filter(const struct option *opt, const char *str,

Signature · 1 line

2.18.0

Arnaldo Carvalho de Melo

maintainer

2018-08-15 19:39 UTC #2 lore raw

Em Wed, Jul 04, 2018 at 05:25:36PM +0200, Jiri Olsa escreveu:

Quoted 15 lines · Jack Henschel

Quoted 14 lines
This is the second version of a patch that improves the error message of the perf events parser when the PMU hardware does not support address filters.
Previously, the perf returned the following error:
Quoted 2 lines
$ perf record -e intel_pt// --filter 'filter sys_write'
--filter option should follow a -e tracepoint or HW tracer option
This implies there is some syntax error present in the command line, which is not true. Rather, notify the user that the CPU does not have support for this feature.
For example, Intel chips based on the Broadwell micro-archticture have the Intel PT PMU, but do not support address filtering.

Quoted 7 lines

Quoted 5 lines
Now, perf prints the following error message:
Quoted 2 lines
$ perf record -e intel_pt// --filter 'filter sys_write'
This CPU does not support address filtering
Signed-off-by Jack Henschel <[email protected]>
Acked-by Jiri Olsa <[email protected]>

Thanks, tested and applied,

- Arnaldo

Quoted 55 lines

thanks,
jirka

Quoted 52 lines

---
 tools/perf/util/parse-events.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

tools/perf/util/parse-events.c +10 ~~-10~~

index 15eec49e71a1..f8cd3e7c9186 100644
@@ -1991,8 +1991,11 @@ static int set_filter(struct perf_evsel *evsel, const void *arg)
 	int nr_addr_filters = 0;
 	struct perf_pmu *pmu = NULL;
 
-	if (evsel == NULL)
-		goto err;
+	if (evsel == NULL) {
+		fprintf(stderr,
+			"--filter option should follow a -e tracepoint or HW tracer option\n");
+		return -1;
+	}
 
 	if (evsel->attr.type == PERF_TYPE_TRACEPOINT) {
 		if (perf_evsel__append_tp_filter(evsel, str) < 0) {

@@ -2014,8 +2017,11 @@ static int set_filter(struct perf_evsel *evsel, const void *arg)
 		perf_pmu__scan_file(pmu, "nr_addr_filters",
 				    "%d", &nr_addr_filters);
 
-	if (!nr_addr_filters)
-		goto err;
+	if (!nr_addr_filters) {
+		fprintf(stderr,
+			"This CPU does not support address filtering\n");
+		return -1;
+	}
 
 	if (perf_evsel__append_addr_filter(evsel, str) < 0) {
 		fprintf(stderr,

@@ -2024,12 +2030,6 @@ static int set_filter(struct perf_evsel *evsel, const void *arg)
 	}
 
 	return 0;
-
-err:
-	fprintf(stderr,
-		"--filter option should follow a -e tracepoint or HW tracer option\n");
-
-	return -1;
 }
 
 int parse_filter(const struct option *opt, const char *str,

Signature · 1 line

2.18.0

tip-bot for Jack Henschel

merge bot

2018-08-23 09:16 UTC #3 lore raw

In reply to Jack Henschel

perf parser: Improve error message for PMU address filters

Commit-ID:  49836f7811f383d8613661fff110ce74f4710d52
Gitweb:     https://git.kernel.org/tip/49836f7811f383d8613661fff110ce74f4710d52
Author:     Jack Henschel <[email protected]>
AuthorDate: Wed, 4 Jul 2018 14:13:45 +0200
Committer:  Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Mon, 20 Aug 2018 08:54:58 -0300

perf parser: Improve error message for PMU address filters

This is the second version of a patch that improves the error message of the perf events parser when the PMU hardware does not support address filters.

Previously, the perf returned the following error:

  $ perf record -e intel_pt// --filter 'filter sys_write'
  --filter option should follow a -e tracepoint or HW tracer option

This implies there is some syntax error present in the command line, which is not true. Rather, notify the user that the CPU does not have support for this feature.

For example, Intel chips based on the Broadwell micro-archticture have the Intel PT PMU, but do not support address filtering.

Now, perf prints the following error message:

  $ perf record -e intel_pt// --filter 'filter sys_write'
  This CPU does not support address filtering

Signed-off-by Jack Henschel <[email protected]>

Tested-by Arnaldo Carvalho de Melo <[email protected]>

Acked-by Jiri Olsa <[email protected]>

Cc Alexander Shishkin <[email protected]>

Cc Peter Zijlstra <[email protected]>

Link http://lkml.kernel.org/r/[email protected] open here

Signed-off-by Arnaldo Carvalho de Melo <[email protected]>

---
 tools/perf/util/parse-events.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

tools/perf/util/parse-events.c +10 ~~-10~~

index 15eec49e71a1..f8cd3e7c9186 100644
@@ -1991,8 +1991,11 @@ static int set_filter(struct perf_evsel *evsel, const void *arg)
 	int nr_addr_filters = 0;
 	struct perf_pmu *pmu = NULL;
 
-	if (evsel == NULL)
-		goto err;
+	if (evsel == NULL) {
+		fprintf(stderr,
+			"--filter option should follow a -e tracepoint or HW tracer option\n");
+		return -1;
+	}
 
 	if (evsel->attr.type == PERF_TYPE_TRACEPOINT) {
 		if (perf_evsel__append_tp_filter(evsel, str) < 0) {

@@ -2014,8 +2017,11 @@ static int set_filter(struct perf_evsel *evsel, const void *arg)
 		perf_pmu__scan_file(pmu, "nr_addr_filters",
 				    "%d", &nr_addr_filters);
 
-	if (!nr_addr_filters)
-		goto err;
+	if (!nr_addr_filters) {
+		fprintf(stderr,
+			"This CPU does not support address filtering\n");
+		return -1;
+	}
 
 	if (perf_evsel__append_addr_filter(evsel, str) < 0) {
 		fprintf(stderr,

@@ -2024,12 +2030,6 @@ static int set_filter(struct perf_evsel *evsel, const void *arg)
 	}
 
 	return 0;
-
-err:
-	fprintf(stderr,
-		"--filter option should follow a -e tracepoint or HW tracer option\n");
-
-	return -1;
 }
 
 int parse_filter(const struct option *opt, const char *str,