perf hist: Basic support for mem_stat accounting

Add a logic to account he->mem_stat based on mem_stat_type in hists.

Each mem_stat entry will have different meaning based on the type so the
index in the array is calculated at runtime using the corresponding
value in the sample.data_src.

Still hists has no mem_stat_types yet so this code won't work for now.

Later hists->mem_stat_types will be allocated based on what users want
in the output actually.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Link: https://lore.kernel.org/r/20250430205548.789750-6-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 39 insertions, 0 deletions

diff --git a/tools/perf/ui/hist.c b/tools/perf/ui/hist.c
index ec44633207aa..2aad46bbd2ed 100644
--- a/tools/perf/ui/hist.c
+++ b/tools/perf/ui/hist.c
@@ -11,6 +11,7 @@
 #include "../util/sort.h"
 #include "../util/evsel.h"
 #include "../util/evlist.h"
+#include "../util/mem-events.h"
 #include "../util/thread.h"
 #include "../util/util.h"
 
@@ -500,6 +501,12 @@ static int64_t hpp__nop_cmp(struct perf_hpp_fmt *fmt __maybe_unused,
 	return 0;
 }
 
+static bool perf_hpp__is_mem_stat_entry(struct perf_hpp_fmt *fmt)
+{
+	(void)fmt;
+	return false;
+}
+
 static bool perf_hpp__is_hpp_entry(struct perf_hpp_fmt *a)
 {
 	return a->header == hpp__header_fn;
@@ -1022,3 +1029,35 @@ int perf_hpp__setup_hists_formats(struct perf_hpp_list *list,
 
 	return 0;
 }
+
+int perf_hpp__alloc_mem_stats(struct perf_hpp_list *list, struct evlist *evlist)
+{
+	struct perf_hpp_fmt *fmt;
+	struct evsel *evsel;
+	enum mem_stat_type mst[16];
+	unsigned nr_mem_stats = 0;
+
+	perf_hpp_list__for_each_format(list, fmt) {
+		if (!perf_hpp__is_mem_stat_entry(fmt))
+			continue;
+
+		assert(nr_mem_stats < ARRAY_SIZE(mst));
+		mst[nr_mem_stats++] = PERF_MEM_STAT_UNKNOWN;
+	}
+
+	if (nr_mem_stats == 0)
+		return 0;
+
+	evlist__for_each_entry(evlist, evsel) {
+		struct hists *hists = evsel__hists(evsel);
+
+		hists->mem_stat_types = calloc(nr_mem_stats,
+					       sizeof(*hists->mem_stat_types));
+		if (hists->mem_stat_types == NULL)
+			return -ENOMEM;
+
+		memcpy(hists->mem_stat_types, mst, nr_mem_stats * sizeof(*mst));
+		hists->nr_mem_stats = nr_mem_stats;
+	}
+	return 0;
+}