[RFC PATCH v3 01/14] perf parse-events: expand add PMU error/verbose messages

Ian Rogers
2020-05-08T05:36:40Z

On a CPU like skylakex an uncore_iio_0 PMU may alias with
uncore_iio_free_running_0. The latter PMU doesn't support fc_mask
as a parameter and so pmu_config_term fails. Typically
parse_events_add_pmu is called in a loop where if one alias succeeds
errors are ignored, however, if multiple errors occur
parse_events__handle_error will currently give a WARN_ONCE.

This change removes the WARN_ONCE in parse_events__handle_error and
makes it a pr_debug. It adds verbose messages to parse_events_add_pmu
warning that non-fatal errors may occur, while giving details on the pmu
and config terms for useful context. pmu_config_term is altered so the
failing term and pmu are present in the case of the 'unknown term'
error which makes spotting the free_running case more straightforward.

Before:
$ perf --debug verbose=3 stat -M llc_misses.pcie_read sleep 1
Using CPUID GenuineIntel-6-55-4
metric expr unc_iio_data_req_of_cpu.mem_read.part0 + unc_iio_data_req_of_cpu.mem_read.part1 + unc_iio_data_req_of_cpu.mem_read.part2 + unc_iio_data_req_of_cpu.mem_read.part3 for LLC_MISSES.PCIE_READ
found event unc_iio_data_req_of_cpu.mem_read.part0
found event unc_iio_data_req_of_cpu.mem_read.part1
found event unc_iio_data_req_of_cpu.mem_read.part2
found event unc_iio_data_req_of_cpu.mem_read.part3
metric expr unc_iio_data_req_of_cpu.mem_read.part0 + unc_iio_data_req_of_cpu.mem_read.part1 + unc_iio_data_req_of_cpu.mem_read.part2 + unc_iio_data_req_of_cpu.mem_read.part3 for LLC_MISSES.PCIE_READ
found event unc_iio_data_req_of_cpu.mem_read.part0
found event unc_iio_data_req_of_cpu.mem_read.part1
found event unc_iio_data_req_of_cpu.mem_read.part2
found event unc_iio_data_req_of_cpu.mem_read.part3
adding {unc_iio_data_req_of_cpu.mem_read.part0,unc_iio_data_req_of_cpu.mem_read.part1,unc_iio_data_req_of_cpu.mem_read.part2,unc_iio_data_req_of_cpu.mem_read.part3}:W,{unc_iio_data_req_of_cpu.mem_read.part0,unc_iio_data_req_of_cpu.mem_read.part1,unc_iio_data_req_of_cpu.mem_read.part2,unc_iio_data_req_of_cpu.mem_read.part3}:W
intel_pt default config: tsc,mtc,mtc_period=3,psb_period=3,pt,branch
WARNING: multiple event parsing errors
...
Invalid event/parameter 'fc_mask'
...

After:
$ perf --debug verbose=3 stat -M llc_misses.pcie_read sleep 1
Using CPUID GenuineIntel-6-55-4
metric expr unc_iio_data_req_of_cpu.mem_read.part0 + unc_iio_data_req_of_cpu.mem_read.part1 + unc_iio_data_req_of_cpu.mem_read.part2 + unc_iio_data_req_of_cpu.mem_read.part3 for LLC_MISSES.PCIE_READ
found event unc_iio_data_req_of_cpu.mem_read.part0
found event unc_iio_data_req_of_cpu.mem_read.part1
found event unc_iio_data_req_of_cpu.mem_read.part2
found event unc_iio_data_req_of_cpu.mem_read.part3
metric expr unc_iio_data_req_of_cpu.mem_read.part0 + unc_iio_data_req_of_cpu.mem_read.part1 + unc_iio_data_req_of_cpu.mem_read.part2 + unc_iio_data_req_of_cpu.mem_read.part3 for LLC_MISSES.PCIE_READ
found event unc_iio_data_req_of_cpu.mem_read.part0
found event unc_iio_data_req_of_cpu.mem_read.part1
found event unc_iio_data_req_of_cpu.mem_read.part2
found event unc_iio_data_req_of_cpu.mem_read.part3
adding {unc_iio_data_req_of_cpu.mem_read.part0,unc_iio_data_req_of_cpu.mem_read.part1,unc_iio_data_req_of_cpu.mem_read.part2,unc_iio_data_req_of_cpu.mem_read.part3}:W,{unc_iio_data_req_of_cpu.mem_read.part0,unc_iio_data_req_of_cpu.mem_read.part1,unc_iio_data_req_of_cpu.mem_read.part2,unc_iio_data_req_of_cpu.mem_read.part3}:W
intel_pt default config: tsc,mtc,mtc_period=3,psb_period=3,pt,branch
Attempting to add event pmu 'uncore_iio_free_running_5' with 'unc_iio_data_req_of_cpu.mem_read.part0,' that may result in non-fatal errors
After aliases, add event pmu 'uncore_iio_free_running_5' with 'fc_mask,ch_mask,umask,event,' that may result in non-fatal errors
Attempting to add event pmu 'uncore_iio_free_running_3' with 'unc_iio_data_req_of_cpu.mem_read.part0,' that may result in non-fatal errors
After aliases, add event pmu 'uncore_iio_free_running_3' with 'fc_mask,ch_mask,umask,event,' that may result in non-fatal errors
Attempting to add event pmu 'uncore_iio_free_running_1' with 'unc_iio_data_req_of_cpu.mem_read.part0,' that may result in non-fatal errors
After aliases, add event pmu 'uncore_iio_free_running_1' with 'fc_mask,ch_mask,umask,event,' that may result in non-fatal errors
Multiple errors dropping message: unknown term 'fc_mask' for pmu 'uncore_iio_free_running_3' (valid terms: event,umask,config,config1,config2,name,period,percore)
...

Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/arch/x86/util/intel-pt.c | 32 +++++++++++++++++-----------
tools/perf/tests/pmu.c | 4 ++--
tools/perf/util/parse-events.c | 29 ++++++++++++++++++++++++-
tools/perf/util/pmu.c | 33 ++++++++++++++++++-----------
tools/perf/util/pmu.h | 2 +-
5 files changed, 72 insertions(+), 28 deletions(-)

diff --git a/tools/perf/arch/x86/util/intel-pt.c b/tools/perf/arch/x86/util/intel-pt.c
index fd9e22d1e366..0fe401ad3347 100644
--- a/tools/perf/arch/x86/util/intel-pt.c
+++ b/tools/perf/arch/x86/util/intel-pt.c
@@ -59,7 +59,8 @@ struct intel_pt_recording {
size_t priv_size;
};

-static int intel_pt_parse_terms_with_default(struct list_head *formats,
+static int intel_pt_parse_terms_with_default(const char *pmu_name,
+ struct list_head *formats,
const char *str,
u64 *config)
{
@@ -78,7 +79,8 @@ static int intel_pt_parse_terms_with_default(struct list_head *formats,
goto out_free;

attr.config = *config;
- err = perf_pmu__config_terms(formats, &attr, terms, true, NULL);
+ err = perf_pmu__config_terms(pmu_name, formats, &attr, terms, true,
+ NULL);
if (err)
goto out_free;

@@ -88,11 +90,12 @@ static int intel_pt_parse_terms_with_default(struct list_head *formats,
return err;
}

-static int intel_pt_parse_terms(struct list_head *formats, const char *str,
- u64 *config)
+static int intel_pt_parse_terms(const char *pmu_name, struct list_head *formats,
+ const char *str, u64 *config)
{
*config = 0;
- return intel_pt_parse_terms_with_default(formats, str, config);
+ return intel_pt_parse_terms_with_default(pmu_name, formats, str,
+ config);
}

static u64 intel_pt_masked_bits(u64 mask, u64 bits)
@@ -229,7 +232,8 @@ static u64 intel_pt_default_config(struct perf_pmu *intel_pt_pmu)

pr_debug2("%s default config: %s\n", intel_pt_pmu->name, buf);

- intel_pt_parse_terms(&intel_pt_pmu->format, buf, &config);
+ intel_pt_parse_terms(intel_pt_pmu->name, &intel_pt_pmu->format, buf,
+ &config);

return config;
}
@@ -337,13 +341,16 @@ static int intel_pt_info_fill(struct auxtrace_record *itr,
if (priv_size != ptr->priv_size)
return -EINVAL;

- intel_pt_parse_terms(&intel_pt_pmu->format, "tsc", &tsc_bit);
- intel_pt_parse_terms(&intel_pt_pmu->format, "noretcomp",
- &noretcomp_bit);
- intel_pt_parse_terms(&intel_pt_pmu->format, "mtc", &mtc_bit);
+ intel_pt_parse_terms(intel_pt_pmu->name, &intel_pt_pmu->format,
+ "tsc", &tsc_bit);
+ intel_pt_parse_terms(intel_pt_pmu->name, &intel_pt_pmu->format,
+ "noretcomp", &noretcomp_bit);
+ intel_pt_parse_terms(intel_pt_pmu->name, &intel_pt_pmu->format,
+ "mtc", &mtc_bit);
mtc_freq_bits = perf_pmu__format_bits(&intel_pt_pmu->format,
"mtc_period");
- intel_pt_parse_terms(&intel_pt_pmu->format, "cyc", &cyc_bit);
+ intel_pt_parse_terms(intel_pt_pmu->name, &intel_pt_pmu->format,
+ "cyc", &cyc_bit);

intel_pt_tsc_ctc_ratio(&tsc_ctc_ratio_n, &tsc_ctc_ratio_d);

@@ -768,7 +775,8 @@ static int intel_pt_recording_options(struct auxtrace_record *itr,
}
}

- intel_pt_parse_terms(&intel_pt_pmu->format, "tsc", &tsc_bit);
+ intel_pt_parse_terms(intel_pt_pmu->name, &intel_pt_pmu->format,
+ "tsc", &tsc_bit);

if (opts->full_auxtrace && (intel_pt_evsel->core.attr.config & tsc_bit))
have_timing_info = true;
diff --git a/tools/perf/tests/pmu.c b/tools/perf/tests/pmu.c
index 74379ff1f7fa..5c11fe2b3040 100644
--- a/tools/perf/tests/pmu.c
+++ b/tools/perf/tests/pmu.c
@@ -156,8 +156,8 @@ int test__pmu(struct test *test __maybe_unused, int subtest __maybe_unused)
if (ret)
break;

- ret = perf_pmu__config_terms(&formats, &attr, terms,
- false, NULL);
+ ret = perf_pmu__config_terms("perf-pmu-test", &formats, &attr,
+ terms, false, NULL);
if (ret)
break;

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index e9464b04f149..0ebc0fd9385a 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -204,7 +204,8 @@ void parse_events__handle_error(struct parse_events_error *err, int idx,
err->help = help;
break;
default:
- WARN_ONCE(1, "WARNING: multiple event parsing errors\n");
+ pr_debug("Multiple errors dropping message: %s (%s)\n",
+ err->str, err->help);
free(err->str);
err->str = str;
free(err->help);
@@ -1422,6 +1423,19 @@ int parse_events_add_pmu(struct parse_events_state *parse_state,
bool use_uncore_alias;
LIST_HEAD(config_terms);

+ if (verbose > 1) {
+ fprintf(stderr, "Attempting to add event pmu '%s' with '",
+ name);
+ if (head_config) {
+ struct parse_events_term *term;
+
+ list_for_each_entry(term, head_config, list) {
+ fprintf(stderr, "%s,", term->config);
+ }
+ }
+ fprintf(stderr, "' that may result in non-fatal errors\n");
+ }
+
pmu = perf_pmu__find(name);
if (!pmu) {
char *err_str;
@@ -1458,6 +1472,19 @@ int parse_events_add_pmu(struct parse_events_state *parse_state,
if (perf_pmu__check_alias(pmu, head_config, &info))
return -EINVAL;

+ if (verbose > 1) {
+ fprintf(stderr, "After aliases, add event pmu '%s' with '",
+ name);
+ if (head_config) {
+ struct parse_events_term *term;
+
+ list_for_each_entry(term, head_config, list) {
+ fprintf(stderr, "%s,", term->config);
+ }
+ }
+ fprintf(stderr, "' that may result in non-fatal errors\n");
+ }
+
/*
* Configure hardcoded terms first, no need to check
* return value when called with fail == 0 ;)
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 92bd7fafcce6..71d0290b616a 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -1056,7 +1056,8 @@ static char *pmu_formats_string(struct list_head *formats)
* Setup one of config[12] attr members based on the
* user input data - term parameter.
*/
-static int pmu_config_term(struct list_head *formats,
+static int pmu_config_term(const char *pmu_name,
+ struct list_head *formats,
struct perf_event_attr *attr,
struct parse_events_term *term,
struct list_head *head_terms,
@@ -1082,16 +1083,24 @@ static int pmu_config_term(struct list_head *formats,

format = pmu_find_format(formats, term->config);
if (!format) {
- if (verbose > 0)
- printf("Invalid event/parameter '%s'\n", term->config);
+ char *pmu_term = pmu_formats_string(formats);
+ char *unknown_term;
+ char *help_msg;
+
+ if (asprintf(&unknown_term,
+ "unknown term '%s' for pmu '%s'",
+ term->config, pmu_name) < 0)
+ unknown_term = strdup("unknown term");
+ help_msg = parse_events_formats_error_string(pmu_term);
if (err) {
- char *pmu_term = pmu_formats_string(formats);
-
parse_events__handle_error(err, term->err_term,
- strdup("unknown term"),
- parse_events_formats_error_string(pmu_term));
- free(pmu_term);
+ unknown_term,
+ help_msg);
+ } else {
+ pr_debug("%s (%s)\n", unknown_term, help_msg);
+ free(unknown_term);
}
+ free(pmu_term);
return -EINVAL;
}

@@ -1168,7 +1177,7 @@ static int pmu_config_term(struct list_head *formats,
return 0;
}

-int perf_pmu__config_terms(struct list_head *formats,
+int perf_pmu__config_terms(const char *pmu_name, struct list_head *formats,
struct perf_event_attr *attr,
struct list_head *head_terms,
bool zero, struct parse_events_error *err)
@@ -1176,7 +1185,7 @@ int perf_pmu__config_terms(struct list_head *formats,
struct parse_events_term *term;

list_for_each_entry(term, head_terms, list) {
- if (pmu_config_term(formats, attr, term, head_terms,
+ if (pmu_config_term(pmu_name, formats, attr, term, head_terms,
zero, err))
return -EINVAL;
}
@@ -1196,8 +1205,8 @@ int perf_pmu__config(struct perf_pmu *pmu, struct perf_event_attr *attr,
bool zero = !!pmu->default_config;

attr->type = pmu->type;
- return perf_pmu__config_terms(&pmu->format, attr, head_terms,
- zero, err);
+ return perf_pmu__config_terms(pmu->name, &pmu->format, attr,
+ head_terms, zero, err);
}

static struct perf_pmu_alias *pmu_find_alias(struct perf_pmu *pmu,
diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
index e119333e93ba..85e0c7f2515c 100644
--- a/tools/perf/util/pmu.h
+++ b/tools/perf/util/pmu.h
@@ -76,7 +76,7 @@ struct perf_pmu *perf_pmu__find_by_type(unsigned int type);
int perf_pmu__config(struct perf_pmu *pmu, struct perf_event_attr *attr,
struct list_head *head_terms,
struct parse_events_error *error);
-int perf_pmu__config_terms(struct list_head *formats,
+int perf_pmu__config_terms(const char *pmu_name, struct list_head *formats,
struct perf_event_attr *attr,
struct list_head *head_terms,
bool zero, struct parse_events_error *error);
--
2.26.2.645.ge9eca65c58-goog