[PATCH 7/7] perf expr: Add source_count for aggregating events

From: Ian Rogers
Date: Fri Nov 05 2021 - 13:10:40 EST

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Events like uncore_imc/cas_count_read/ on Skylake open multiple events
and then aggregate in the metric leader. To determine the average value
per event the number of these events is needed. Add a source_count
function that returns this value by counting the number of events with
the given metric leader. For most events the value is 1 but for
uncore_imc/cas_count_read/ it can yield values like 6.

Add a generic test, but manually tested with a test metric that uses
the function.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/tests/expr.c | 12 +++++++
tools/perf/util/evsel.c | 12 +++++++
tools/perf/util/evsel.h | 1 +
tools/perf/util/expr.c | 27 ++++++++++++---
tools/perf/util/expr.h | 3 ++
tools/perf/util/expr.l | 1 +
tools/perf/util/expr.y | 65 ++++++++++++++++++++---------------
tools/perf/util/stat-shadow.c | 7 +++-
8 files changed, 95 insertions(+), 33 deletions(-)

diff --git a/tools/perf/tests/expr.c b/tools/perf/tests/expr.c
index 0c09ccc76665..f14d11ac353e 100644
--- a/tools/perf/tests/expr.c
+++ b/tools/perf/tests/expr.c
@@ -171,6 +171,18 @@ int test__expr(struct test *t __maybe_unused, int subtest __maybe_unused)
TEST_ASSERT_VAL("#num_packages", expr__parse(&num_packages, ctx, "#num_packages") == 0);
TEST_ASSERT_VAL("#num_dies >= #num_packages", num_dies >= num_packages);

+ /*
+ * Source count returns the number of events aggregating in a leader
+ * event including the leader. Check parsing yields an id.
+ */
+ expr__ctx_clear(ctx);
+ TEST_ASSERT_VAL("source count",
+ expr__find_ids("source_count(EVENT1)",
+ NULL, ctx) == 0);
+ TEST_ASSERT_VAL("source count", hashmap__size(ctx->ids) == 1);
+ TEST_ASSERT_VAL("source count", hashmap__find(ctx->ids, "EVENT1",
+ (void **)&val_ptr));
+
expr__ctx_free(ctx);

return 0;
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 2cfc2935d1d2..9a2a5087f00a 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -3018,3 +3018,15 @@ void evsel__set_leader(struct evsel *evsel, struct evsel *leader)
{
evsel->core.leader = &leader->core;
}
+
+int evsel__source_count(const struct evsel *evsel)
+{
+ struct evsel *pos;
+ int count = 0;
+
+ evlist__for_each_entry(evsel->evlist, pos) {
+ if (pos->metric_leader == evsel)
+ count++;
+ }
+ return count;
+}
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 846c827934de..d733a8458a52 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -484,6 +484,7 @@ struct evsel *evsel__leader(struct evsel *evsel);
bool evsel__has_leader(struct evsel *evsel, struct evsel *leader);
bool evsel__is_leader(struct evsel *evsel);
void evsel__set_leader(struct evsel *evsel, struct evsel *leader);
+int evsel__source_count(const struct evsel *evsel);

/*
* Macro to swap the bit-field postition and size.
diff --git a/tools/perf/util/expr.c b/tools/perf/util/expr.c
index 15af8b8ef5e7..1d532b9fed29 100644
--- a/tools/perf/util/expr.c
+++ b/tools/perf/util/expr.c
@@ -23,7 +23,10 @@ extern int expr_debug;

struct expr_id_data {
union {
- double val;
+ struct {
+ double val;
+ int source_count;
+ } val;
struct {
double val;
const char *metric_name;
@@ -140,6 +143,13 @@ int expr__add_id(struct expr_parse_ctx *ctx, const char *id)

/* Caller must make sure id is allocated */
int expr__add_id_val(struct expr_parse_ctx *ctx, const char *id, double val)
+{
+ return expr__add_id_val_source_count(ctx, id, val, /*source_count=*/1);
+}
+
+/* Caller must make sure id is allocated */
+int expr__add_id_val_source_count(struct expr_parse_ctx *ctx, const char *id,
+ double val, int source_count)
{
struct expr_id_data *data_ptr = NULL, *old_data = NULL;
char *old_key = NULL;
@@ -148,7 +158,8 @@ int expr__add_id_val(struct expr_parse_ctx *ctx, const char *id, double val)
data_ptr = malloc(sizeof(*data_ptr));
if (!data_ptr)
return -ENOMEM;
- data_ptr->val = val;
+ data_ptr->val.val = val;
+ data_ptr->val.source_count = source_count;
data_ptr->kind = EXPR_ID_DATA__VALUE;

ret = hashmap__set(ctx->ids, id, data_ptr,
@@ -244,7 +255,7 @@ int expr__resolve_id(struct expr_parse_ctx *ctx, const char *id,

switch (data->kind) {
case EXPR_ID_DATA__VALUE:
- pr_debug2("lookup(%s): val %f\n", id, data->val);
+ pr_debug2("lookup(%s): val %f\n", id, data->val.val);
break;
case EXPR_ID_DATA__REF:
pr_debug2("lookup(%s): ref metric name %s\n", id,
@@ -255,7 +266,7 @@ int expr__resolve_id(struct expr_parse_ctx *ctx, const char *id,
pr_debug("%s failed to count\n", id);
return -1;
}
- pr_debug("processing metric: %s EXIT: %f\n", id, data->val);
+ pr_debug("processing metric: %s EXIT: %f\n", id, data->ref.val);
break;
case EXPR_ID_DATA__REF_VALUE:
pr_debug2("lookup(%s): ref val %f metric name %s\n", id,
@@ -370,11 +381,17 @@ int expr__find_ids(const char *expr, const char *one,
double expr_id_data__value(const struct expr_id_data *data)
{
if (data->kind == EXPR_ID_DATA__VALUE)
- return data->val;
+ return data->val.val;
assert(data->kind == EXPR_ID_DATA__REF_VALUE);
return data->ref.val;
}

+double expr_id_data__source_count(const struct expr_id_data *data)
+{
+ assert(data->kind == EXPR_ID_DATA__VALUE);
+ return data->val.source_count;
+}
+
double expr__get_literal(const char *literal)
{
static struct cpu_topology *topology;
diff --git a/tools/perf/util/expr.h b/tools/perf/util/expr.h
index a6ab7f2b23d1..bd2116983bbb 100644
--- a/tools/perf/util/expr.h
+++ b/tools/perf/util/expr.h
@@ -40,6 +40,8 @@ void expr__ctx_free(struct expr_parse_ctx *ctx);
void expr__del_id(struct expr_parse_ctx *ctx, const char *id);
int expr__add_id(struct expr_parse_ctx *ctx, const char *id);
int expr__add_id_val(struct expr_parse_ctx *ctx, const char *id, double val);
+int expr__add_id_val_source_count(struct expr_parse_ctx *ctx, const char *id,
+ double val, int source_count);
int expr__add_ref(struct expr_parse_ctx *ctx, struct metric_ref *ref);
int expr__get_id(struct expr_parse_ctx *ctx, const char *id,
struct expr_id_data **data);
@@ -55,6 +57,7 @@ int expr__find_ids(const char *expr, const char *one,
struct expr_parse_ctx *ids);

double expr_id_data__value(const struct expr_id_data *data);
+double expr_id_data__source_count(const struct expr_id_data *data);
double expr__get_literal(const char *literal);

#endif
diff --git a/tools/perf/util/expr.l b/tools/perf/util/expr.l
index cf6e3c710502..0a13eb20c814 100644
--- a/tools/perf/util/expr.l
+++ b/tools/perf/util/expr.l
@@ -107,6 +107,7 @@ max { return MAX; }
min { return MIN; }
if { return IF; }
else { return ELSE; }
+source_count { return SOURCE_COUNT; }
{literal} { return literal(yyscanner); }
{number} { return value(yyscanner); }
{symbol} { return str(yyscanner, ID, sctx->runtime); }
diff --git a/tools/perf/util/expr.y b/tools/perf/util/expr.y
index ba6c6dbf30c8..d5d10f21097a 100644
--- a/tools/perf/util/expr.y
+++ b/tools/perf/util/expr.y
@@ -3,6 +3,7 @@
#define YYDEBUG 1
#include <assert.h>
#include <math.h>
+#include <stdlib.h>
#include "util/debug.h"
#define IN_EXPR_Y 1
#include "expr.h"
@@ -36,7 +37,7 @@
} ids;
}

-%token ID NUMBER MIN MAX IF ELSE LITERAL D_RATIO EXPR_ERROR
+%token ID NUMBER MIN MAX IF ELSE LITERAL D_RATIO SOURCE_COUNT EXPR_ERROR
%left MIN MAX IF
%left '|'
%left '^'
@@ -82,6 +83,40 @@ static struct ids union_expr(struct ids ids1, struct ids ids2)
return result;
}

+static struct ids handle_id(struct expr_parse_ctx *ctx, char *id,
+ bool compute_ids, bool source_count)
+{
+ struct ids result;
+ if (!compute_ids) {
+ /*
+ * Compute the event's value from ID. If the ID isn't known then
+ * it isn't used to compute the formula so set to NAN.
+ */
+ struct expr_id_data *data;
+
+ result.val = NAN;
+ if (expr__resolve_id(ctx, id, &data) == 0) {
+ result.val = source_count
+ ? expr_id_data__source_count(data)
+ : expr_id_data__value(data);
+ }
+ result.ids = NULL;
+ free(id);
+ } else {
+ /*
+ * Set the value to BOTTOM to show that any value is possible
+ * when the event is computed. Create a set of just the ID.
+ */
+ result.val = BOTTOM;
+ result.ids = ids__new();
+ if (!result.ids || ids__insert(result.ids, id)) {
+ pr_err("Error creating IDs for '%s'", id);
+ free(id);
+ }
+ }
+ return result;
+}
+
/*
* If we're not computing ids or $1 and $3 are constants, compute the new
* constant value using OP. Its invariant that there are no ids. If computing
@@ -167,32 +202,8 @@ expr: NUMBER
$$.val = $1;
$$.ids = NULL;
}
-| ID
-{
- if (!compute_ids) {
- /*
- * Compute the event's value from ID. If the ID isn't known then
- * it isn't used to compute the formula so set to NAN.
- */
- struct expr_id_data *data;
-
- $$.val = NAN;
- if (expr__resolve_id(ctx, $1, &data) == 0)
- $$.val = expr_id_data__value(data);
-
- $$.ids = NULL;
- free($1);
- } else {
- /*
- * Set the value to BOTTOM to show that any value is possible
- * when the event is computed. Create a set of just the ID.
- */
- $$.val = BOTTOM;
- $$.ids = ids__new();
- if (!$$.ids || ids__insert($$.ids, $1))
- YYABORT;
- }
-}
+| ID { $$ = handle_id(ctx, $1, compute_ids, /*source_count=*/false); }
+| SOURCE_COUNT '(' ID ')' { $$ = handle_id(ctx, $3, compute_ids, /*source_count=*/true); }
| expr '|' expr { BINARY_LONG_OP($$, |, $1, $3); }
| expr '&' expr { BINARY_LONG_OP($$, &, $1, $3); }
| expr '^' expr { BINARY_LONG_OP($$, ^, $1, $3); }
diff --git a/tools/perf/util/stat-shadow.c b/tools/perf/util/stat-shadow.c
index 69f3cf3b4a44..ce0ce8ac2874 100644
--- a/tools/perf/util/stat-shadow.c
+++ b/tools/perf/util/stat-shadow.c
@@ -828,10 +828,12 @@ static int prepare_metric(struct evsel **metric_events,
struct saved_value *v;
struct stats *stats;
u64 metric_total = 0;
+ int source_count;

if (!strcmp(metric_events[i]->name, "duration_time")) {
stats = &walltime_nsecs_stats;
scale = 1e-9;
+ source_count = 1;
} else {
v = saved_value_lookup(metric_events[i], cpu, false,
STAT_NONE, 0, st,
@@ -840,6 +842,7 @@ static int prepare_metric(struct evsel **metric_events,
break;
stats = &v->stats;
scale = 1.0;
+ source_count = evsel__source_count(metric_events[i]);

if (v->metric_other)
metric_total = v->metric_total;
@@ -848,7 +851,9 @@ static int prepare_metric(struct evsel **metric_events,
if (!n)
return -ENOMEM;

- expr__add_id_val(pctx, n, metric_total ? : avg_stats(stats) * scale);
+ expr__add_id_val_source_count(pctx, n,
+ metric_total ? : avg_stats(stats) * scale,
+ source_count);
}

for (j = 0; metric_refs && metric_refs[j].metric_name; j++) {
--
2.34.0.rc0.344.g81b53c2807-goog

Next message: Alan Maguire: "[PATCH v2 bpf-next 2/2] selftests/bpf: add exception handling selftests for tp_bpf program"
Previous message: Ian Rogers: "[PATCH 6/7] perf expr: Add metric literals for topology."
In reply to: Ian Rogers: "[PATCH 6/7] perf expr: Add metric literals for topology."
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]