perf parse-events: Make add PMU verbose output clearer

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)
  ...

  So before you see a 'WARNING: multiple event parsing errors' and
  'Invalid event/parameter'. After you see 'Attempting... that may result
  in non-fatal errors' then 'Multiple errors...' with details that
  'fc_mask' wasn't known to a free running counter. While not completely
  clean, this makes it clearer that an error hasn't really occurred.

v2. addresses review feedback from Jiri Olsa <jolsa@redhat.com>.

Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lore.kernel.org/lkml/20200513220635.54700-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 20 insertions, 12 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 @@ out_free:
 	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;