[PATCH V2 2/5] tools/perf: Add dynamic headers for perf report columns

[Athira Rajeev <atrajeev@linux.vnet.ibm.com>]

Currently the header string for different columns in perf report
is fixed. Some fields of perf sample could have different meaning
for different architectures than the meaning conveyed by the header
string. An example is the new field 'var2_w' of perf_sample_weight
structure. This is presently captured as 'Local INSTR Latency' in
perf mem report. But this could be used to denote a different latency
cycle in another architecture.

Introduce a weak function arch_perf_header_entry() to set
the arch specific header string for the fields which can contain dynamic
header. If the architecture do not have this function, fall back to the
default header string value.

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
---
 tools/perf/util/event.h |  1 +
 tools/perf/util/sort.c  | 19 ++++++++++++++++++-
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index f603edbbbc6f..6106a9c134c9 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -427,5 +427,6 @@ void  cpu_map_data__synthesize(struct perf_record_cpu_map_data *data, struct per
 
 void arch_perf_parse_sample_weight(struct perf_sample *data, const __u64 *array, u64 type);
 void arch_perf_synthesize_sample_weight(const struct perf_sample *data, __u64 *array, u64 type);
+const char *arch_perf_header_entry(const char *se_header);
 
 #endif /* __PERF_RECORD_H */
diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
index 552b590485bf..eeb03e749181 100644
--- a/tools/perf/util/sort.c
+++ b/tools/perf/util/sort.c
@@ -25,6 +25,7 @@
 #include <traceevent/event-parse.h>
 #include "mem-events.h"
 #include "annotate.h"
+#include "event.h"
 #include "time-utils.h"
 #include "cgroup.h"
 #include "machine.h"
@@ -45,6 +46,7 @@
 regex_t		ignore_callees_regex;
 int		have_ignore_callees = 0;
 enum sort_mode	sort__mode = SORT_MODE__NORMAL;
+const char	*dynamic_headers[] = {"local_ins_lat"};
 
 /*
  * Replaces all occurrences of a char used with the:
@@ -1816,6 +1818,16 @@ struct sort_dimension {
 	int			taken;
 };
 
+const char * __weak arch_perf_header_entry(const char *se_header)
+{
+	return se_header;
+}
+
+static void sort_dimension_add_dynamic_header(struct sort_dimension *sd)
+{
+	sd->entry->se_header = arch_perf_header_entry(sd->entry->se_header);
+}
+
 #define DIM(d, n, func) [d] = { .name = n, .entry = &(func) }
 
 static struct sort_dimension common_sort_dimensions[] = {
@@ -2739,7 +2751,7 @@ int sort_dimension__add(struct perf_hpp_list *list, const char *tok,
 			struct evlist *evlist,
 			int level)
 {
-	unsigned int i;
+	unsigned int i, j;
 
 	for (i = 0; i < ARRAY_SIZE(common_sort_dimensions); i++) {
 		struct sort_dimension *sd = &common_sort_dimensions[i];
@@ -2747,6 +2759,11 @@ int sort_dimension__add(struct perf_hpp_list *list, const char *tok,
 		if (strncasecmp(tok, sd->name, strlen(tok)))
 			continue;
 
+		for (j = 0; j < ARRAY_SIZE(dynamic_headers); j++) {
+			if (!strcmp(dynamic_headers[j], sd->name))
+				sort_dimension_add_dynamic_header(sd);
+		}
+
 		if (sd->entry == &sort_parent) {
 			int ret = regcomp(&parent_regex, parent_pattern, REG_EXTENDED);
 			if (ret) {
-- 
1.8.3.1