linux-kernel - [PATCH 2/2] perf, tools, record: Fix -c/-F options for cpu event aliases

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Date:   Fri, 20 Oct 2017 13:27:55 -0700
From:   Andi Kleen <andi@...stfloor.org>
To:     acme@...nel.org
Cc:     jolsa@...nel.org, linux-kernel@...r.kernel.org,
        Andi Kleen <ak@...ux.intel.com>
Subject: [PATCH 2/2] perf, tools, record: Fix -c/-F options for cpu event aliases

From: Andi Kleen <ak@...ux.intel.com>

The Intel PMU event aliases have a implicit
period= specifier to set the default period.

Unfortunately this breaks overriding these periods with -c or
-F, because the alias terms look like they are user specified
to the internal parser, and user specified event qualifiers override
the command line options.

Track that they are coming from aliases by adding a
"weak" state to the term. Any weak terms don't override
command line options.

I only did it for -c/-F for now, I think that's the
only case that's broken currently.

Before:

$ perf record -c 1000 -vv -e uops_issued.any
...
  { sample_period, sample_freq }   2000003

After:

$ perf record -c 1000 -vv -e uops_issued.any
...
  { sample_period, sample_freq }   1000

Signed-off-by: Andi Kleen <ak@...ux.intel.com>
---
 tools/perf/util/evsel.c        | 12 ++++++++----
 tools/perf/util/evsel.h        |  1 +
 tools/perf/util/parse-events.c |  2 ++
 tools/perf/util/parse-events.h |  3 +++
 tools/perf/util/pmu.c          |  5 +++++
 5 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index d1f63b93bf69..4376cdfaea49 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -733,12 +733,16 @@ static void apply_config_terms(struct perf_evsel *evsel,
 	list_for_each_entry(term, config_terms, list) {
 		switch (term->type) {
 		case PERF_EVSEL__CONFIG_TERM_PERIOD:
-			attr->sample_period = term->val.period;
-			attr->freq = 0;
+			if (!(term->weak && opts->user_interval != ULLONG_MAX)) {
+				attr->sample_period = term->val.period;
+				attr->freq = 0;
+			}
 			break;
 		case PERF_EVSEL__CONFIG_TERM_FREQ:
-			attr->sample_freq = term->val.freq;
-			attr->freq = 1;
+			if (!(term->weak && opts->user_freq != UINT_MAX)) {
+				attr->sample_freq = term->val.freq;
+				attr->freq = 1;
+			}
 			break;
 		case PERF_EVSEL__CONFIG_TERM_TIME:
 			if (term->val.time)
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 6728d8d6e513..e315f91739bc 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -65,6 +65,7 @@ struct perf_evsel_config_term {
 		bool	overwrite;
 		char	*branch;
 	} val;
+	bool weak;
 };
 
 /** struct perf_evsel - event selector
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 04f35db063ee..c773cdd9aa4b 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -1115,6 +1115,7 @@ do {								\
 	INIT_LIST_HEAD(&__t->list);				\
 	__t->type       = PERF_EVSEL__CONFIG_TERM_ ## __type;	\
 	__t->val.__name = __val;				\
+	__t->weak	= term->weak;				\
 	list_add_tail(&__t->list, head_terms);			\
 } while (0)
 
@@ -2409,6 +2410,7 @@ static int new_term(struct parse_events_term **_term,
 
 	*term = *temp;
 	INIT_LIST_HEAD(&term->list);
+	term->weak = false;
 
 	switch (term->type_val) {
 	case PARSE_EVENTS__TERM_TYPE_NUM:
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index 3909ca0639f2..e5638f06b431 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -100,6 +100,9 @@ struct parse_events_term {
 	/* error string indexes for within parsed string */
 	int err_term;
 	int err_val;
+
+	/* Coming from implicit alias */
+	bool weak;
 };
 
 struct parse_events_error {
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 94cf2c29fed6..2b12bcb845a8 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -404,6 +404,11 @@ static int pmu_alias_terms(struct perf_pmu_alias *alias,
 			parse_events_terms__purge(&list);
 			return ret;
 		}
+		/*
+		 * Weak terms don't override command line options,
+		 * which we don't want for implicit terms in aliases.
+		 */
+		cloned->weak = true;
 		list_add_tail(&cloned->list, &list);
 	}
 	list_splice(&list, terms);
-- 
2.13.6