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

Andi Kleen
2020-05-09T00:16:56Z

This seems like a independent bug fix and should probably
be pushed independently of the rest.

Perhaps add a Fixes: tag.

Reviewed-by: Andi Kleen <ak@linux.inte.com>

On Thu, May 07, 2020 at 10:36:16PM -0700, Ian Rogers wrote:
> 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
>