perf stat: Add aggr_nr metric parser support

Introduce the `aggr_nr` function to the metric expression parser.
`aggr_nr` allows metric formulas to dynamically utilize the number of
aggregated targets (`aggr->nr`) instead of relying on the static
`source_count` (which represents the static socket or node count).

This adds the `AGGR_NR` token to the lexer and parser, updates the
expression parsing context helpers to store `aggr_nr`, and feeds
`aggr->nr` from the aggregation structure in `prepare_metric`.

Assisted-by: Gemini:gemini-3.1-pro-preview
Signed-off-by: Chun-Tse Shao <ctshao@google.com>
Tested-by: Zide Chen <zide.chen@intel.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Thomas Falcon <thomas.falcon@intel.com>
Cc: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 22 insertions, 4 deletions

diff --git a/tools/perf/util/expr.c b/tools/perf/util/expr.c
index 644769e92708..232998fef72b 100644
--- a/tools/perf/util/expr.c
+++ b/tools/perf/util/expr.c
@@ -27,6 +27,7 @@ struct expr_id_data {
 		struct {
 			double val;
 			int source_count;
+			int aggr_nr;
 		} val;
 		struct {
 			double val;
@@ -151,8 +152,8 @@ int expr__add_id_val(struct expr_parse_ctx *ctx, const char *id, double val)
 }
 
 /* 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)
+int expr__add_id_val_source_count_aggr_nr(struct expr_parse_ctx *ctx, const char *id,
+					  double val, int source_count, int aggr_nr)
 {
 	struct expr_id_data *data_ptr = NULL, *old_data = NULL;
 	char *old_key = NULL;
@@ -163,6 +164,7 @@ int expr__add_id_val_source_count(struct expr_parse_ctx *ctx, const char *id,
 		return -ENOMEM;
 	data_ptr->val.val = val;
 	data_ptr->val.source_count = source_count;
+	data_ptr->val.aggr_nr = aggr_nr;
 	data_ptr->kind = EXPR_ID_DATA__VALUE;
 
 	ret = hashmap__set(ctx->ids, id, data_ptr, &old_key, &old_data);
@@ -171,12 +173,20 @@ int expr__add_id_val_source_count(struct expr_parse_ctx *ctx, const char *id,
 	} else if (old_data) {
 		data_ptr->val.val += old_data->val.val;
 		data_ptr->val.source_count += old_data->val.source_count;
+		data_ptr->val.aggr_nr += old_data->val.aggr_nr;
 	}
 	free(old_key);
 	free(old_data);
 	return ret;
 }
 
+/* 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)
+{
+	return expr__add_id_val_source_count_aggr_nr(ctx, id, val, source_count, 1);
+}
+
 int expr__add_ref(struct expr_parse_ctx *ctx, struct metric_ref *ref)
 {
 	struct expr_id_data *data_ptr = NULL, *old_data = NULL;
@@ -390,8 +400,16 @@ double expr_id_data__value(const struct expr_id_data *data)
 
 double expr_id_data__source_count(const struct expr_id_data *data)
 {
-	assert(data->kind == EXPR_ID_DATA__VALUE);
-	return data->val.source_count;
+	if (data->kind == EXPR_ID_DATA__VALUE)
+		return data->val.source_count;
+	return 1.0;
+}
+
+double expr_id_data__aggr_nr(const struct expr_id_data *data)
+{
+	if (data->kind == EXPR_ID_DATA__VALUE)
+		return data->val.aggr_nr;
+	return 1.0;
 }
 
 double expr__get_literal(const char *literal, const struct expr_scanner_ctx *ctx)