[PATCH v21 12/19] perf, tools: Support long descriptions with perf list

[Sukadev Bhattiprolu]

Previously we were dropping the useful longer descriptions that some
events have in the event list completely. This patch makes them appear with
perf list.

Old perf list:

baclears:
  baclears.all
       [Counts the number of baclears]

vs new:

perf list -v:
...
baclears:
  baclears.all
       [The BACLEARS event counts the number of times the front end is
        resteered, mainly when the Branch Prediction Unit cannot provide
	a correct prediction and this is corrected by the Branch Address
	Calculator at the front end. The BACLEARS.ANY event counts the
        number of baclears for any type of branch]

Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Signed-off-by: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Acked-by: Ingo Molnar <mingo@xxxxxxxxxx>
---

Changelog[v15]
	- [Jir Olsa, Andi Kleen] Fix usage strings; update man page.

Changelog[v14]
	- [Jiri Olsa] Break up independent parts of the patch into
	  separate patches.

Changelog[v18]:
	- Fix minor conflict in tools/perf/builtin-list.c; add long_desc_flag
	  parameter to new print_pmu_events() call site.

Changelog[v21]
	- Fix minor conflicts in tools/perf/builtin-list.c
---
 tools/perf/Documentation/perf-list.txt |  6 +++++-
 tools/perf/builtin-list.c              | 16 +++++++++++-----
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/tools/perf/Documentation/perf-list.txt b/tools/perf/Documentation/perf-list.txt
index 72209bc..41857cc 100644
--- a/tools/perf/Documentation/perf-list.txt
+++ b/tools/perf/Documentation/perf-list.txt
@@ -8,7 +8,7 @@ perf-list - List all symbolic event types
 SYNOPSIS
 --------
 [verse]
-'perf list' [--no-desc] [hw|sw|cache|tracepoint|pmu|event_glob]
+'perf list' [--no-desc] [--long-desc] [hw|sw|cache|tracepoint|pmu|event_glob]
 
 DESCRIPTION
 -----------
@@ -20,6 +20,10 @@ OPTIONS
 --no-desc::
 Don't print descriptions.
 
+-v::
+--long-desc::
+Print longer event descriptions.
+
 
 [[EVENT_MODIFIERS]]
 EVENT MODIFIERS
diff --git a/tools/perf/builtin-list.c b/tools/perf/builtin-list.c
index b14cb16..ba9322f 100644
--- a/tools/perf/builtin-list.c
+++ b/tools/perf/builtin-list.c
@@ -22,14 +22,17 @@ int cmd_list(int argc, const char **argv, const char *prefix __maybe_unused)
 {
 	int i;
 	bool raw_dump = false;
+	bool long_desc_flag = false;
 	struct option list_options[] = {
 		OPT_BOOLEAN(0, "raw-dump", &raw_dump, "Dump raw events"),
 		OPT_BOOLEAN('d', "desc", &desc_flag,
 			    "Print extra event descriptions. --no-desc to not print."),
+		OPT_BOOLEAN('v', "long-desc", &long_desc_flag,
+			    "Print longer event descriptions."),
 		OPT_END()
 	};
 	const char * const list_usage[] = {
-		"perf list [--no-desc] [hw|sw|cache|tracepoint|pmu|sdt|event_glob]",
+		"perf list [<options>] [hw|sw|cache|tracepoint|pmu|sdt|event_glob]",
 		NULL
 	};
 
@@ -44,7 +47,7 @@ int cmd_list(int argc, const char **argv, const char *prefix __maybe_unused)
 		printf("\nList of pre-defined events (to be used in -e):\n\n");
 
 	if (argc == 0) {
-		print_events(NULL, raw_dump, !desc_flag);
+		print_events(NULL, raw_dump, !desc_flag, long_desc_flag);
 		return 0;
 	}
 
@@ -65,14 +68,16 @@ int cmd_list(int argc, const char **argv, const char *prefix __maybe_unused)
 			 strcmp(argv[i], "hwcache") == 0)
 			print_hwcache_events(NULL, raw_dump);
 		else if (strcmp(argv[i], "pmu") == 0)
-			print_pmu_events(NULL, raw_dump, !desc_flag);
+			print_pmu_events(NULL, raw_dump, !desc_flag,
+						long_desc_flag);
 		else if (strcmp(argv[i], "sdt") == 0)
 			print_sdt_events(NULL, NULL, raw_dump);
 		else if ((sep = strchr(argv[i], ':')) != NULL) {
 			int sep_idx;
 
 			if (sep == NULL) {
-				print_events(argv[i], raw_dump, !desc_flag);
+				print_events(argv[i], raw_dump, !desc_flag,
+							long_desc_flag);
 				continue;
 			}
 			sep_idx = sep - argv[i];
@@ -94,7 +99,8 @@ int cmd_list(int argc, const char **argv, const char *prefix __maybe_unused)
 			print_symbol_events(s, PERF_TYPE_SOFTWARE,
 					    event_symbols_sw, PERF_COUNT_SW_MAX, raw_dump);
 			print_hwcache_events(s, raw_dump);
-			print_pmu_events(s, raw_dump, !desc_flag);
+			print_pmu_events(s, raw_dump, !desc_flag,
+						long_desc_flag);
 			print_tracepoint_events(NULL, s, raw_dump);
 			print_sdt_events(NULL, s, raw_dump);
 			free(s);
-- 
1.8.3.1