[PATCH 19/48] perf report: Add 'typeoff' sort key

[Namhyung Kim]

The typeoff sort key shows the data type name, offset and the name of
the field.  This is useful to see which field in the struct is accessed
most frequently.

  $ perf report -s type,typeoff --hierarchy --stdio
  ...
  #     Overhead  Data Type / Data Type Offset
  # ............  ............................
  #
  ...
        1.23%     struct cfs_rq
           0.19%    struct cfs_rq +404 (throttle_count)
           0.19%    struct cfs_rq +0 (load.weight)
           0.19%    struct cfs_rq +336 (leaf_cfs_rq_list.next)
           0.09%    struct cfs_rq +272 (propagate)
           0.09%    struct cfs_rq +196 (removed.nr)
           0.09%    struct cfs_rq +80 (curr)
           0.09%    struct cfs_rq +544 (lt_b_children_throttled)
           0.06%    struct cfs_rq +320 (rq)

Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
 tools/perf/Documentation/perf-report.txt |  1 +
 tools/perf/util/annotate.c               |  1 +
 tools/perf/util/hist.h                   |  1 +
 tools/perf/util/sort.c                   | 83 +++++++++++++++++++++++-
 tools/perf/util/sort.h                   |  2 +
 5 files changed, 87 insertions(+), 1 deletion(-)

diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
index aec34417090b..b57eb51b47aa 100644
--- a/tools/perf/Documentation/perf-report.txt
+++ b/tools/perf/Documentation/perf-report.txt
@@ -119,6 +119,7 @@ OPTIONS
 	  to the previous instruction in cycles. And currently supported only on X86
 	- simd: Flags describing a SIMD operation. "e" for empty Arm SVE predicate. "p" for partial Arm SVE predicate
 	- type: Data type of sample memory access.
+	- typeoff: Offset in the data type of sample memory access.
 
 	By default, comm, dso and symbol keys are used.
 	(i.e. --sort comm,dso,symbol)
diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index ab942331720d..49d5b61e19e6 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -3679,6 +3679,7 @@ struct annotated_data_type *hist_entry__get_data_type(struct hist_entry *he)
 						    op_loc->offset,
 						    he->stat.nr_events,
 						    he->stat.period);
+		he->mem_type_off = op_loc->offset;
 		return mem_type;
 	}
 	return NULL;
diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h
index 9bfed867f288..941176afcebc 100644
--- a/tools/perf/util/hist.h
+++ b/tools/perf/util/hist.h
@@ -83,6 +83,7 @@ enum hist_column {
 	HISTC_ADDR,
 	HISTC_SIMD,
 	HISTC_TYPE,
+	HISTC_TYPE_OFFSET,
 	HISTC_NR_COLS, /* Last entry */
 };
 
diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
index 01300831333e..98eafef282df 100644
--- a/tools/perf/util/sort.c
+++ b/tools/perf/util/sort.c
@@ -2146,8 +2146,10 @@ static void sort__type_init(struct hist_entry *he)
 		return;
 
 	he->mem_type = hist_entry__get_data_type(he);
-	if (he->mem_type == NULL)
+	if (he->mem_type == NULL) {
 		he->mem_type = &unknown_type;
+		he->mem_type_off = 0;
+	}
 }
 
 static int64_t
@@ -2191,6 +2193,84 @@ struct sort_entry sort_type = {
 	.se_width_idx	= HISTC_TYPE,
 };
 
+/* --sort typeoff */
+
+static int64_t
+sort__typeoff_sort(struct hist_entry *left, struct hist_entry *right)
+{
+	struct annotated_data_type *left_type = left->mem_type;
+	struct annotated_data_type *right_type = right->mem_type;
+	int64_t ret;
+
+	if (!left_type) {
+		sort__type_init(left);
+		left_type = left->mem_type;
+	}
+
+	if (!right_type) {
+		sort__type_init(right);
+		right_type = right->mem_type;
+	}
+
+	ret = strcmp(left_type->self.type_name, right_type->self.type_name);
+	if (ret)
+		return ret;
+	return left->mem_type_off - right->mem_type_off;
+}
+
+static void fill_member_name(char *buf, size_t sz, struct annotated_member *m,
+			     int offset, bool first)
+{
+	struct annotated_member *child;
+
+	if (list_empty(&m->children))
+		return;
+
+	list_for_each_entry(child, &m->children, node) {
+		if (child->offset <= offset && offset < child->offset + child->size) {
+			int len = 0;
+
+			/* It can have anonymous struct/union members */
+			if (child->var_name) {
+				len = scnprintf(buf, sz, "%s%s",
+						first ? "" : ".", child->var_name);
+				first = false;
+			}
+
+			fill_member_name(buf + len, sz - len, child, offset, first);
+			return;
+		}
+	}
+}
+
+static int hist_entry__typeoff_snprintf(struct hist_entry *he, char *bf,
+				     size_t size, unsigned int width __maybe_unused)
+{
+	struct annotated_data_type *he_type = he->mem_type;
+	char buf[4096];
+
+	buf[0] = '\0';
+	if (list_empty(&he_type->self.children))
+		snprintf(buf, sizeof(buf), "no field");
+	else
+		fill_member_name(buf, sizeof(buf), &he_type->self,
+				 he->mem_type_off, true);
+	buf[4095] = '\0';
+
+	return repsep_snprintf(bf, size, "%s %+d (%s)", he_type->self.type_name,
+			       he->mem_type_off, buf);
+}
+
+struct sort_entry sort_type_offset = {
+	.se_header	= "Data Type Offset",
+	.se_cmp		= sort__type_cmp,
+	.se_collapse	= sort__typeoff_sort,
+	.se_sort	= sort__typeoff_sort,
+	.se_init	= sort__type_init,
+	.se_snprintf	= hist_entry__typeoff_snprintf,
+	.se_width_idx	= HISTC_TYPE_OFFSET,
+};
+
 
 struct sort_dimension {
 	const char		*name;
@@ -2247,6 +2327,7 @@ static struct sort_dimension common_sort_dimensions[] = {
 	DIM(SORT_GLOBAL_RETIRE_LAT, "retire_lat", sort_global_p_stage_cyc),
 	DIM(SORT_SIMD, "simd", sort_simd),
 	DIM(SORT_ANNOTATE_DATA_TYPE, "type", sort_type),
+	DIM(SORT_ANNOTATE_DATA_TYPE_OFFSET, "typeoff", sort_type_offset),
 };
 
 #undef DIM
diff --git a/tools/perf/util/sort.h b/tools/perf/util/sort.h
index aabf0b8331a3..d806adcc1e1e 100644
--- a/tools/perf/util/sort.h
+++ b/tools/perf/util/sort.h
@@ -113,6 +113,7 @@ struct hist_entry {
 	u64			p_stage_cyc;
 	u8			cpumode;
 	u8			depth;
+	int			mem_type_off;
 	struct simd_flags	simd_flags;
 
 	/* We are added by hists__add_dummy_entry. */
@@ -247,6 +248,7 @@ enum sort_type {
 	SORT_GLOBAL_RETIRE_LAT,
 	SORT_SIMD,
 	SORT_ANNOTATE_DATA_TYPE,
+	SORT_ANNOTATE_DATA_TYPE_OFFSET,
 
 	/* branch stack specific sort keys */
 	__SORT_BRANCH_STACK,
-- 
2.42.0.655.g421f12c284-goog