[PATCH v1 6/9] perf list: Simplify symbol event printing

Ian Rogers
2022-11-14T07:53:13Z

The current code computes an array of symbol names then sorts and
prints them. Use a strlist to create a list of names that is
sorted and then print it.

Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/util/print-events.c | 79 +++++++++-------------------------
1 file changed, 21 insertions(+), 58 deletions(-)

diff --git a/tools/perf/util/print-events.c b/tools/perf/util/print-events.c
index ff7793944246..d53dba033597 100644
--- a/tools/perf/util/print-events.c
+++ b/tools/perf/util/print-events.c
@@ -52,14 +52,6 @@ static const struct event_symbol event_symbols_tool[PERF_TOOL_MAX] = {
},
};

-static int cmp_string(const void *a, const void *b)
-{
- const char * const *as = a;
- const char * const *bs = b;
-
- return strcmp(*as, *bs);
-}
-
/*
* Print the events from <debugfs_mount_point>/tracing/events
*/
@@ -298,77 +290,48 @@ void print_symbol_events(const char *event_glob, unsigned int type,
struct event_symbol *syms, unsigned int max,
bool name_only)
{
- unsigned int i, evt_i = 0, evt_num = 0;
- char name[MAX_NAME_LEN];
- char **evt_list = NULL;
- bool evt_num_known = false;
-
-restart:
- if (evt_num_known) {
- evt_list = zalloc(sizeof(char *) * evt_num);
- if (!evt_list)
- goto out_enomem;
- syms -= max;
- }
+ struct strlist *evt_name_list = strlist__new(NULL, NULL);
+ struct str_node *nd;

- for (i = 0; i < max; i++, syms++) {
+ if (!evt_name_list) {
+ pr_debug("Failed to allocate new strlist for symbol events\n");
+ return;
+ }
+ for (unsigned int i = 0; i < max; i++) {
/*
* New attr.config still not supported here, the latest
* example was PERF_COUNT_SW_CGROUP_SWITCHES
*/
- if (syms->symbol == NULL)
+ if (syms[i].symbol == NULL)
continue;

- if (event_glob != NULL && !(strglobmatch(syms->symbol, event_glob) ||
- (syms->alias && strglobmatch(syms->alias, event_glob))))
+ if (event_glob != NULL && !(strglobmatch(syms[i].symbol, event_glob) ||
+ (syms[i].alias && strglobmatch(syms[i].alias, event_glob))))
continue;

if (!is_event_supported(type, i))
continue;

- if (!evt_num_known) {
- evt_num++;
- continue;
- }
-
- if (!name_only && strlen(syms->alias))
- snprintf(name, MAX_NAME_LEN, "%s OR %s", syms->symbol, syms->alias);
- else
- strlcpy(name, syms->symbol, MAX_NAME_LEN);
+ if (strlen(syms[i].alias)) {
+ char name[MAX_NAME_LEN];

- evt_list[evt_i] = strdup(name);
- if (evt_list[evt_i] == NULL)
- goto out_enomem;
- evt_i++;
+ snprintf(name, MAX_NAME_LEN, "%s OR %s", syms[i].symbol, syms[i].alias);
+ strlist__add(evt_name_list, name);
+ } else
+ strlist__add(evt_name_list, syms[i].symbol);
}

- if (!evt_num_known) {
- evt_num_known = true;
- goto restart;
- }
- qsort(evt_list, evt_num, sizeof(char *), cmp_string);
- evt_i = 0;
- while (evt_i < evt_num) {
+ strlist__for_each_entry(nd, evt_name_list) {
if (name_only) {
- printf("%s ", evt_list[evt_i++]);
+ printf("%s ", nd->s);
continue;
}
- printf(" %-50s [%s]\n", evt_list[evt_i++], event_type_descriptors[type]);
+ printf(" %-50s [%s]\n", nd->s, event_type_descriptors[type]);
}
- if (evt_num && pager_in_use())
+ if (!strlist__empty(evt_name_list) && pager_in_use())
printf("\n");

-out_free:
- evt_num = evt_i;
- for (evt_i = 0; evt_i < evt_num; evt_i++)
- zfree(&evt_list[evt_i]);
- zfree(&evt_list);
- return;
-
-out_enomem:
- printf("FATAL: not enough memory to print %s\n", event_type_descriptors[type]);
- if (evt_list)
- goto out_free;
+ strlist__delete(evt_name_list);
}

/*
--
2.38.1.431.g37b22c650d-goog