perf pmu: Remove str from perf_pmu_alias

Currently the value is only used in perf list.

Compute the value just when needed to avoid unnecessary overhead.

Recycle the strbuf to avoid memory allocation overhead.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20230830070753.1821629-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 8dbb700..152cda8 100644 (file)
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -51,11 +51,6 @@ struct perf_pmu_alias {
         * json events.
         */
        char *topic;
-       /**
-        * @str: Comma separated parameter list like
-        * "event=0xcd,umask=0x1,ldlat=0x3".
-        */
-       char *str;
        /** @terms: Owned list of the original parsed parameters. */
        struct list_head terms;
        /** @list: List element of struct perf_pmu aliases. */
@@ -408,7 +403,6 @@ static void perf_pmu_free_alias(struct perf_pmu_alias *newalias)
        zfree(&newalias->desc);
        zfree(&newalias->long_desc);
        zfree(&newalias->topic);
-       zfree(&newalias->str);
        zfree(&newalias->pmu_name);
        parse_events_terms__purge(&newalias->terms);
        free(newalias);
@@ -489,7 +483,7 @@ static int update_alias(const struct pmu_event *pe,
        assign_str(pe->name, "long_desc", &data->alias->long_desc, pe->long_desc);
        assign_str(pe->name, "topic", &data->alias->topic, pe->topic);
        data->alias->per_pkg = pe->perpkg;
-       if (assign_str(pe->name, "value", &data->alias->str, pe->event)) {
+       if (pe->event) {
                parse_events_terms__purge(&data->alias->terms);
                ret = parse_events_terms(&data->alias->terms, pe->event, /*input=*/NULL);
        }
@@ -511,7 +505,6 @@ static int perf_pmu__new_alias(struct perf_pmu *pmu, const char *name,
        int ret;
        const char *long_desc = NULL, *topic = NULL, *unit = NULL, *pmu_name = NULL;
        bool deprecated = false, perpkg = false;
-       struct strbuf sb;
 
        if (perf_pmu__find_alias(pmu, name, /*load=*/ false)) {
                /* Alias was already created/loaded. */
@@ -531,7 +524,6 @@ static int perf_pmu__new_alias(struct perf_pmu *pmu, const char *name,
        if (!alias)
                return -ENOMEM;
 
-       alias->str = NULL;
        INIT_LIST_HEAD(&alias->terms);
        alias->scale = 1.0;
        alias->unit[0] = '\0';
@@ -574,17 +566,6 @@ static int perf_pmu__new_alias(struct perf_pmu *pmu, const char *name,
                }
        }
 
-       /* Scan event and remove leading zeroes, spaces, newlines, some
-        * platforms have terms specified as
-        * event=0x0091 (read from files ../<PMU>/events/<FILE>
-        * and terms specified as event=0x91 (read from JSON files).
-        *
-        * Rebuild string to make alias->str member comparable.
-        */
-       zfree(&alias->str);
-       strbuf_init(&sb, /*hint=*/ 0);
-       parse_events_term__to_strbuf(&alias->terms, &sb);
-       alias->str = strbuf_detach(&sb, /*sz=*/ NULL);
        if (!pe)
                pmu->sysfs_aliases++;
        else
@@ -1682,7 +1663,9 @@ int perf_pmu__for_each_event(struct perf_pmu *pmu, bool skip_duplicate_pmus,
                .pmu = pmu,
        };
        int ret = 0;
+       struct strbuf sb;
 
+       strbuf_init(&sb, /*hint=*/ 0);
        pmu_add_cpu_aliases(pmu);
        list_for_each_entry(event, &pmu->aliases, list) {
                size_t buf_used;
@@ -1710,14 +1693,16 @@ int perf_pmu__for_each_event(struct perf_pmu *pmu, bool skip_duplicate_pmus,
                info.desc = event->desc;
                info.long_desc = event->long_desc;
                info.encoding_desc = buf + buf_used;
+               parse_events_term__to_strbuf(&event->terms, &sb);
                buf_used += snprintf(buf + buf_used, sizeof(buf) - buf_used,
-                               "%s/%s/", info.pmu_name, event->str) + 1;
+                               "%s/%s/", info.pmu_name, sb.buf) + 1;
                info.topic = event->topic;
-               info.str = event->str;
+               info.str = sb.buf;
                info.deprecated = event->deprecated;
                ret = cb(state, &info);
                if (ret)
-                       return ret;
+                       goto out;
+               strbuf_setlen(&sb, /*len=*/ 0);
        }
        if (pmu->selectable) {
                info.name = buf;
@@ -1732,6 +1717,8 @@ int perf_pmu__for_each_event(struct perf_pmu *pmu, bool skip_duplicate_pmus,
                info.deprecated = false;
                ret = cb(state, &info);
        }
+out:
+       strbuf_release(&sb);
        return ret;
 }