perf annotate: Add a hashmap for symbol histogram

Now symbol histogram uses an array to save per-offset sample counts.
But it wastes a lot of memory if the symbol has a few samples only.
Add a hashmap to save values only for actual samples.

For now, it has duplicate histogram (one in the existing array and
another in the new hash map).  Once it can convert to use the hash
in all places, we can get rid of the array later.

Reviewed-by: Ian Rogers <irogers@google.com>
Reviewed-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240304230815.1440583-2-namhyung@kernel.org

1 files changed, 2 insertions, 0 deletions

diff --git a/tools/perf/util/annotate.h b/tools/perf/util/annotate.h
index 94435607c958..a2b0c8210740 100644
--- a/tools/perf/util/annotate.h
+++ b/tools/perf/util/annotate.h
@@ -12,6 +12,7 @@
 #include "symbol_conf.h"
 #include "mutex.h"
 #include "spark.h"
+#include "hashmap.h"
 
 struct hist_browser_timer;
 struct hist_entry;
@@ -280,6 +281,7 @@ struct annotated_source {
 	size_t			sizeof_sym_hist;
 	struct sym_hist		*histograms;
 	struct annotation_line	**offsets;
+	struct hashmap	   	*samples;
 	int    			nr_histograms;
 	int			nr_entries;
 	int			nr_asm_entries;