[RFC PATCH v3 07/14] perf expr: migrate expr ids table to libbpf's hashmap

From: Ian Rogers
Date: Fri May 08 2020 - 01:36:58 EST

Use a hashmap between a char* string and a double* value. While bpf's
hashmap entries are size_t in size, we can't guarantee sizeof(size_t) >=
sizeof(double). Avoid a memory allocation when gathering ids by making 0.0
a special value encoded as NULL.

Suggested by Andi Kleen:
https://lore.kernel.org/lkml/20200224210308.GQ160988@xxxxxxxxxxxxxxxxxxxx/
and seconded by Jiri Olsa:
https://lore.kernel.org/lkml/20200423112915.GH1136647@krava/

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/tests/expr.c | 40 ++++++-----
tools/perf/tests/pmu-events.c | 25 +++----
tools/perf/util/expr.c | 129 +++++++++++++++++++---------------
tools/perf/util/expr.h | 22 +++---
tools/perf/util/expr.y | 22 +-----
tools/perf/util/metricgroup.c | 87 +++++++++++------------
tools/perf/util/stat-shadow.c | 49 ++++++++-----
7 files changed, 193 insertions(+), 181 deletions(-)

diff --git a/tools/perf/tests/expr.c b/tools/perf/tests/expr.c
index 3f742612776a..5e606fd5a2c6 100644
--- a/tools/perf/tests/expr.c
+++ b/tools/perf/tests/expr.c
@@ -19,11 +19,9 @@ static int test(struct expr_parse_ctx *ctx, const char *e, double val2)
int test__expr(struct test *t __maybe_unused, int subtest __maybe_unused)
{
const char *p;
- const char **other;
- double val;
- int i, ret;
+ double val, *val_ptr;
+ int ret;
struct expr_parse_ctx ctx;
- int num_other;

expr__ctx_init(&ctx);
expr__add_id(&ctx, "FOO", 1);
@@ -52,25 +50,29 @@ int test__expr(struct test *t __maybe_unused, int subtest __maybe_unused)
ret = expr__parse(&val, &ctx, p, 1);
TEST_ASSERT_VAL("missing operand", ret == -1);

+ hashmap__clear(&ctx.ids);
TEST_ASSERT_VAL("find other",
- expr__find_other("FOO + BAR + BAZ + BOZO", "FOO", &other, &num_other, 1) == 0);
- TEST_ASSERT_VAL("find other", num_other == 3);
- TEST_ASSERT_VAL("find other", !strcmp(other[0], "BAR"));
- TEST_ASSERT_VAL("find other", !strcmp(other[1], "BAZ"));
- TEST_ASSERT_VAL("find other", !strcmp(other[2], "BOZO"));
- TEST_ASSERT_VAL("find other", other[3] == NULL);
+ expr__find_other("FOO + BAR + BAZ + BOZO", "FOO",
+ &ctx, 1) == 0);
+ TEST_ASSERT_VAL("find other", hashmap__size(&ctx.ids) == 3);
+ TEST_ASSERT_VAL("find other", hashmap__find(&ctx.ids, "BAR",
+ (void **)&val_ptr));
+ TEST_ASSERT_VAL("find other", hashmap__find(&ctx.ids, "BAZ",
+ (void **)&val_ptr));
+ TEST_ASSERT_VAL("find other", hashmap__find(&ctx.ids, "BOZO",
+ (void **)&val_ptr));

+ hashmap__clear(&ctx.ids);
TEST_ASSERT_VAL("find other",
- expr__find_other("EVENT1\\,param\\=?@ + EVENT2\\,param\\=?@", NULL,
- &other, &num_other, 3) == 0);
- TEST_ASSERT_VAL("find other", num_other == 2);
- TEST_ASSERT_VAL("find other", !strcmp(other[0], "EVENT1,param=3/"));
- TEST_ASSERT_VAL("find other", !strcmp(other[1], "EVENT2,param=3/"));
- TEST_ASSERT_VAL("find other", other[2] == NULL);
+ expr__find_other("EVENT1\\,param\\=?@ + EVENT2\\,param\\=?@",
+ NULL, &ctx, 3) == 0);
+ TEST_ASSERT_VAL("find other", hashmap__size(&ctx.ids) == 2);
+ TEST_ASSERT_VAL("find other", hashmap__find(&ctx.ids, "EVENT1,param=3/",
+ (void **)&val_ptr));
+ TEST_ASSERT_VAL("find other", hashmap__find(&ctx.ids, "EVENT2,param=3/",
+ (void **)&val_ptr));

- for (i = 0; i < num_other; i++)
- zfree(&other[i]);
- free((void *)other);
+ expr__ctx_clear(&ctx);

return 0;
}
diff --git a/tools/perf/tests/pmu-events.c b/tools/perf/tests/pmu-events.c
index c18b9ce8cace..054550ee811c 100644
--- a/tools/perf/tests/pmu-events.c
+++ b/tools/perf/tests/pmu-events.c
@@ -428,8 +428,6 @@ static int test_parsing(void)
struct pmu_events_map *map;
struct pmu_event *pe;
int i, j, k;
- const char **ids;
- int idnum;
int ret = 0;
struct expr_parse_ctx ctx;
double result;
@@ -443,13 +441,17 @@ static int test_parsing(void)
}
j = 0;
for (;;) {
+ struct hashmap_entry *cur;
+ size_t bkt;
+
pe = &map->table[j++];
if (!pe->name && !pe->metric_group && !pe->metric_name)
break;
if (!pe->metric_expr)
continue;
- if (expr__find_other(pe->metric_expr, NULL,
- &ids, &idnum, 0) < 0) {
+ expr__ctx_init(&ctx);
+ if (expr__find_other(pe->metric_expr, NULL, &ctx, 0)
+ < 0) {
pr_debug("Parse other failed for map %s %s %s\n",
map->cpuid, map->version, map->type);
pr_debug("On metric %s\n", pe->metric_name);
@@ -457,18 +459,19 @@ static int test_parsing(void)
ret++;
continue;
}
- expr__ctx_init(&ctx);

/*
* Add all ids with a made up value. The value may
* trigger divide by zero when subtracted and so try to
* make them unique.
*/
- for (k = 0; k < idnum; k++)
- expr__add_id(&ctx, ids[k], k + 1);
+ k = 1;
+ hashmap__for_each_entry((&ctx.ids), cur, bkt)
+ expr__add_id(&ctx, strdup(cur->key), k++);

- for (k = 0; k < idnum; k++) {
- if (check_parse_id(ids[k], map == cpus_map, pe))
+ hashmap__for_each_entry((&ctx.ids), cur, bkt) {
+ if (check_parse_id(cur->key, map == cpus_map,
+ pe))
ret++;
}

@@ -479,9 +482,7 @@ static int test_parsing(void)
pr_debug("On expression %s\n", pe->metric_expr);
ret++;
}
- for (k = 0; k < idnum; k++)
- zfree(&ids[k]);
- free(ids);
+ expr__ctx_clear(&ctx);
}
}
return ret;
diff --git a/tools/perf/util/expr.c b/tools/perf/util/expr.c
index 8b4ce704a68d..f64ab91c432b 100644
--- a/tools/perf/util/expr.c
+++ b/tools/perf/util/expr.c
@@ -4,25 +4,76 @@
#include "expr.h"
#include "expr-bison.h"
#include "expr-flex.h"
+#include <linux/kernel.h>

#ifdef PARSER_DEBUG
extern int expr_debug;
#endif

+static size_t key_hash(const void *key, void *ctx __maybe_unused)
+{
+ const char *str = (const char *)key;
+ size_t hash = 0;
+
+ while (*str != '\0') {
+ hash *= 31;
+ hash += *str;
+ str++;
+ }
+ return hash;
+}
+
+static bool key_equal(const void *key1, const void *key2,
+ void *ctx __maybe_unused)
+{
+ return !strcmp((const char *)key1, (const char *)key2);
+}
+
/* Caller must make sure id is allocated */
-void expr__add_id(struct expr_parse_ctx *ctx, const char *name, double val)
+int expr__add_id(struct expr_parse_ctx *ctx, const char *name, double val)
{
- int idx;
+ double *val_ptr = NULL, *old_val = NULL;
+ char *old_key = NULL;
+ int ret;
+
+ if (val != 0.0) {
+ val_ptr = malloc(sizeof(double));
+ if (!val_ptr)
+ return -ENOMEM;
+ *val_ptr = val;
+ }
+ ret = hashmap__set(&ctx->ids, name, val_ptr,
+ (const void **)&old_key, (void **)&old_val);
+ free(old_key);
+ free(old_val);
+ return ret;
+}
+
+int expr__get_id(struct expr_parse_ctx *ctx, const char *id, double *val_ptr)
+{
+ double *data;

- assert(ctx->num_ids < MAX_PARSE_ID);
- idx = ctx->num_ids++;
- ctx->ids[idx].name = name;
- ctx->ids[idx].val = val;
+ if (!hashmap__find(&ctx->ids, id, (void **)&data))
+ return -1;
+ *val_ptr = (data == NULL) ? 0.0 : *data;
+ return 0;
}

void expr__ctx_init(struct expr_parse_ctx *ctx)
{
- ctx->num_ids = 0;
+ hashmap__init(&ctx->ids, key_hash, key_equal, NULL);
+}
+
+void expr__ctx_clear(struct expr_parse_ctx *ctx)
+{
+ struct hashmap_entry *cur;
+ size_t bkt;
+
+ hashmap__for_each_entry((&ctx->ids), cur, bkt) {
+ free((char *)cur->key);
+ free(cur->value);
+ }
+ hashmap__clear(&ctx->ids);
}

static int
@@ -56,61 +107,25 @@ __expr__parse(double *val, struct expr_parse_ctx *ctx, const char *expr,
return ret;
}

-int expr__parse(double *final_val, struct expr_parse_ctx *ctx, const char *expr, int runtime)
+int expr__parse(double *final_val, struct expr_parse_ctx *ctx,
+ const char *expr, int runtime)
{
return __expr__parse(final_val, ctx, expr, EXPR_PARSE, runtime) ? -1 : 0;
}

-static bool
-already_seen(const char *val, const char *one, const char **other,
- int num_other)
-{
- int i;
-
- if (one && !strcasecmp(one, val))
- return true;
- for (i = 0; i < num_other; i++)
- if (!strcasecmp(other[i], val))
- return true;
- return false;
-}
-
-int expr__find_other(const char *expr, const char *one, const char ***other,
- int *num_other, int runtime)
+int expr__find_other(const char *expr, const char *one,
+ struct expr_parse_ctx *ctx, int runtime)
{
- int err, i = 0, j = 0;
- struct expr_parse_ctx ctx;
-
- expr__ctx_init(&ctx);
- err = __expr__parse(NULL, &ctx, expr, EXPR_OTHER, runtime);
- if (err)
- return -1;
-
- *other = malloc((ctx.num_ids + 1) * sizeof(char *));
- if (!*other)
- return -ENOMEM;
-
- for (i = 0, j = 0; i < ctx.num_ids; i++) {
- const char *str = ctx.ids[i].name;
-
- if (already_seen(str, one, *other, j))
- continue;
-
- str = strdup(str);
- if (!str)
- goto out;
- (*other)[j++] = str;
- }
- (*other)[j] = NULL;
-
-out:
- if (i != ctx.num_ids) {
- while (--j)
- free((char *) (*other)[i]);
- free(*other);
- err = -1;
+ double *old_val = NULL;
+ char *old_key = NULL;
+ int ret = __expr__parse(NULL, ctx, expr, EXPR_OTHER, runtime);
+
+ if (one) {
+ hashmap__delete(&ctx->ids, one,
+ (const void **)&old_key, (void **)&old_val);
+ free(old_key);
+ free(old_val);
}

- *num_other = j;
- return err;
+ return ret;
}
diff --git a/tools/perf/util/expr.h b/tools/perf/util/expr.h
index 40fc452b0f2b..f01bd5ecb09d 100644
--- a/tools/perf/util/expr.h
+++ b/tools/perf/util/expr.h
@@ -2,17 +2,10 @@
#ifndef PARSE_CTX_H
#define PARSE_CTX_H 1

-#define EXPR_MAX_OTHER 64
-#define MAX_PARSE_ID EXPR_MAX_OTHER
-
-struct expr_parse_id {
- const char *name;
- double val;
-};
+#include <bpf/hashmap.h>

struct expr_parse_ctx {
- int num_ids;
- struct expr_parse_id ids[MAX_PARSE_ID];
+ struct hashmap ids;
};

struct expr_scanner_ctx {
@@ -21,9 +14,12 @@ struct expr_scanner_ctx {
};

void expr__ctx_init(struct expr_parse_ctx *ctx);
-void expr__add_id(struct expr_parse_ctx *ctx, const char *id, double val);
-int expr__parse(double *final_val, struct expr_parse_ctx *ctx, const char *expr, int runtime);
-int expr__find_other(const char *expr, const char *one, const char ***other,
- int *num_other, int runtime);
+void expr__ctx_clear(struct expr_parse_ctx *ctx);
+int expr__add_id(struct expr_parse_ctx *ctx, const char *id, double val);
+int expr__get_id(struct expr_parse_ctx *ctx, const char *id, double *val_ptr);
+int expr__parse(double *final_val, struct expr_parse_ctx *ctx,
+ const char *expr, int runtime);
+int expr__find_other(const char *expr, const char *one,
+ struct expr_parse_ctx *ids, int runtime);

#endif
diff --git a/tools/perf/util/expr.y b/tools/perf/util/expr.y
index 3b49b230b111..bf3e898e3055 100644
--- a/tools/perf/util/expr.y
+++ b/tools/perf/util/expr.y
@@ -47,19 +47,6 @@ static void expr_error(double *final_val __maybe_unused,
pr_debug("%s\n", s);
}

-static int lookup_id(struct expr_parse_ctx *ctx, char *id, double *val)
-{
- int i;
-
- for (i = 0; i < ctx->num_ids; i++) {
- if (!strcasecmp(ctx->ids[i].name, id)) {
- *val = ctx->ids[i].val;
- return 0;
- }
- }
- return -1;
-}
-
%}
%%

@@ -73,12 +60,7 @@ all_other: all_other other

other: ID
{
- if (ctx->num_ids + 1 >= EXPR_MAX_OTHER) {
- pr_err("failed: way too many variables");
- YYABORT;
- }
-
- ctx->ids[ctx->num_ids++].name = $1;
+ expr__add_id(ctx, $1, 0.0);
}
|
MIN | MAX | IF | ELSE | SMT_ON | NUMBER | '|' | '^' | '&' | '-' | '+' | '*' | '/' | '%' | '(' | ')' | ','
@@ -93,7 +75,7 @@ if_expr:
;

expr: NUMBER
- | ID { if (lookup_id(ctx, $1, &$$) < 0) {
+ | ID { if (expr__get_id(ctx, $1, &$$)) {
pr_debug("%s not found\n", $1);
free($1);
YYABORT;
diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index b071df373f8b..37be5a368d6e 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -85,8 +85,7 @@ static void metricgroup__rblist_init(struct rblist *metric_events)

struct egroup {
struct list_head nd;
- int idnum;
- const char **ids;
+ struct expr_parse_ctx pctx;
const char *metric_name;
const char *metric_expr;
const char *metric_unit;
@@ -94,19 +93,21 @@ struct egroup {
};

static struct evsel *find_evsel_group(struct evlist *perf_evlist,
- const char **ids,
- int idnum,
+ struct expr_parse_ctx *pctx,
struct evsel **metric_events,
bool *evlist_used)
{
struct evsel *ev;
- int i = 0, j = 0;
bool leader_found;
+ const size_t idnum = hashmap__size(&pctx->ids);
+ size_t i = 0;
+ int j = 0;
+ double *val_ptr;

evlist__for_each_entry (perf_evlist, ev) {
if (evlist_used[j++])
continue;
- if (!strcmp(ev->name, ids[i])) {
+ if (hashmap__find(&pctx->ids, ev->name, (void **)&val_ptr)) {
if (!metric_events[i])
metric_events[i] = ev;
i++;
@@ -118,7 +119,8 @@ static struct evsel *find_evsel_group(struct evlist *perf_evlist,
memset(metric_events, 0,
sizeof(struct evsel *) * idnum);

- if (!strcmp(ev->name, ids[i])) {
+ if (hashmap__find(&pctx->ids, ev->name,
+ (void **)&val_ptr)) {
if (!metric_events[i])
metric_events[i] = ev;
i++;
@@ -175,19 +177,20 @@ static int metricgroup__setup_events(struct list_head *groups,
list_for_each_entry (eg, groups, nd) {
struct evsel **metric_events;

- metric_events = calloc(sizeof(void *), eg->idnum + 1);
+ metric_events = calloc(sizeof(void *),
+ hashmap__size(&eg->pctx.ids) + 1);
if (!metric_events) {
ret = -ENOMEM;
break;
}
- evsel = find_evsel_group(perf_evlist, eg->ids, eg->idnum,
- metric_events, evlist_used);
+ evsel = find_evsel_group(perf_evlist, &eg->pctx, metric_events,
+ evlist_used);
if (!evsel) {
pr_debug("Cannot resolve %s: %s\n",
eg->metric_name, eg->metric_expr);
continue;
}
- for (i = 0; i < eg->idnum; i++)
+ for (i = 0; metric_events[i]; i++)
metric_events[i]->collect_stat = true;
me = metricgroup__lookup(metric_events_list, evsel, true);
if (!me) {
@@ -415,20 +418,20 @@ void metricgroup__print(bool metrics, bool metricgroups, char *filter,
}

static void metricgroup__add_metric_weak_group(struct strbuf *events,
- const char **ids,
- int idnum)
+ struct expr_parse_ctx *ctx)
{
+ struct hashmap_entry *cur;
+ size_t bkt, i = 0;
bool no_group = false;
- int i;

- for (i = 0; i < idnum; i++) {
- pr_debug("found event %s\n", ids[i]);
+ hashmap__for_each_entry((&ctx->ids), cur, bkt) {
+ pr_debug("found event %s\n", (const char *)cur->key);
/*
* Duration time maps to a software event and can make
* groups not count. Always use it outside a
* group.
*/
- if (!strcmp(ids[i], "duration_time")) {
+ if (!strcmp(cur->key, "duration_time")) {
if (i > 0)
strbuf_addf(events, "}:W,");
strbuf_addf(events, "duration_time");
@@ -437,21 +440,22 @@ static void metricgroup__add_metric_weak_group(struct strbuf *events,
}
strbuf_addf(events, "%s%s",
i == 0 || no_group ? "{" : ",",
- ids[i]);
+ (const char *)cur->key);
no_group = false;
+ i++;
}
if (!no_group)
strbuf_addf(events, "}:W");
}

static void metricgroup__add_metric_non_group(struct strbuf *events,
- const char **ids,
- int idnum)
+ struct expr_parse_ctx *ctx)
{
- int i;
+ struct hashmap_entry *cur;
+ size_t bkt;

- for (i = 0; i < idnum; i++)
- strbuf_addf(events, ",%s", ids[i]);
+ hashmap__for_each_entry((&ctx->ids), cur, bkt)
+ strbuf_addf(events, ",%s", (const char *)cur->key);
}

static void metricgroup___watchdog_constraint_hint(const char *name, bool foot)
@@ -495,32 +499,32 @@ int __weak arch_get_runtimeparam(void)
static int __metricgroup__add_metric(struct strbuf *events,
struct list_head *group_list, struct pmu_event *pe, int runtime)
{
-
- const char **ids;
- int idnum;
struct egroup *eg;

- if (expr__find_other(pe->metric_expr, NULL, &ids, &idnum, runtime) < 0)
- return -EINVAL;
-
- if (events->len > 0)
- strbuf_addf(events, ",");
-
- if (metricgroup__has_constraint(pe))
- metricgroup__add_metric_non_group(events, ids, idnum);
- else
- metricgroup__add_metric_weak_group(events, ids, idnum);
-
eg = malloc(sizeof(*eg));
if (!eg)
return -ENOMEM;

- eg->ids = ids;
- eg->idnum = idnum;
+ expr__ctx_init(&eg->pctx);
eg->metric_name = pe->metric_name;
eg->metric_expr = pe->metric_expr;
eg->metric_unit = pe->unit;
eg->runtime = runtime;
+
+ if (expr__find_other(pe->metric_expr, NULL, &eg->pctx, runtime) < 0) {
+ expr__ctx_clear(&eg->pctx);
+ free(eg);
+ return -EINVAL;
+ }
+
+ if (events->len > 0)
+ strbuf_addf(events, ",");
+
+ if (metricgroup__has_constraint(pe))
+ metricgroup__add_metric_non_group(events, &eg->pctx);
+ else
+ metricgroup__add_metric_weak_group(events, &eg->pctx);
+
list_add_tail(&eg->nd, group_list);

return 0;
@@ -603,12 +607,9 @@ static int metricgroup__add_metric_list(const char *list, struct strbuf *events,
static void metricgroup__free_egroups(struct list_head *group_list)
{
struct egroup *eg, *egtmp;
- int i;

list_for_each_entry_safe (eg, egtmp, group_list, nd) {
- for (i = 0; i < eg->idnum; i++)
- zfree(&eg->ids[i]);
- zfree(&eg->ids);
+ expr__ctx_clear(&eg->pctx);
list_del_init(&eg->nd);
free(eg);
}
diff --git a/tools/perf/util/stat-shadow.c b/tools/perf/util/stat-shadow.c
index 9bd7a8d2a858..c44dc814b377 100644
--- a/tools/perf/util/stat-shadow.c
+++ b/tools/perf/util/stat-shadow.c
@@ -323,35 +323,46 @@ void perf_stat__collect_metric_expr(struct evlist *evsel_list)
{
struct evsel *counter, *leader, **metric_events, *oc;
bool found;
- const char **metric_names;
+ struct expr_parse_ctx ctx;
+ struct hashmap_entry *cur;
+ size_t bkt;
int i;
- int num_metric_names;

+ expr__ctx_init(&ctx);
evlist__for_each_entry(evsel_list, counter) {
bool invalid = false;

leader = counter->leader;
if (!counter->metric_expr)
continue;
+
+ expr__ctx_clear(&ctx);
metric_events = counter->metric_events;
if (!metric_events) {
- if (expr__find_other(counter->metric_expr, counter->name,
- &metric_names, &num_metric_names, 1) < 0)
+ if (expr__find_other(counter->metric_expr,
+ counter->name,
+ &ctx, 1) < 0)
continue;

metric_events = calloc(sizeof(struct evsel *),
- num_metric_names + 1);
- if (!metric_events)
+ hashmap__size(&ctx.ids) + 1);
+ if (!metric_events) {
+ expr__ctx_clear(&ctx);
return;
+ }
counter->metric_events = metric_events;
}

- for (i = 0; i < num_metric_names; i++) {
+ i = 0;
+ hashmap__for_each_entry((&ctx.ids), cur, bkt) {
+ const char *metric_name = (const char *)cur->key;
+
found = false;
if (leader) {
/* Search in group */
for_each_group_member (oc, leader) {
- if (!strcasecmp(oc->name, metric_names[i]) &&
+ if (!strcasecmp(oc->name,
+ metric_name) &&
!oc->collect_stat) {
found = true;
break;
@@ -360,7 +371,8 @@ void perf_stat__collect_metric_expr(struct evlist *evsel_list)
}
if (!found) {
/* Search ignoring groups */
- oc = perf_stat__find_event(evsel_list, metric_names[i]);
+ oc = perf_stat__find_event(evsel_list,
+ metric_name);
}
if (!oc) {
/* Deduping one is good enough to handle duplicated PMUs. */
@@ -373,27 +385,28 @@ void perf_stat__collect_metric_expr(struct evlist *evsel_list)
* of events. So we ask the user instead to add the missing
* events.
*/
- if (!printed || strcasecmp(printed, metric_names[i])) {
+ if (!printed ||
+ strcasecmp(printed, metric_name)) {
fprintf(stderr,
"Add %s event to groups to get metric expression for %s\n",
- metric_names[i],
+ metric_name,
counter->name);
- printed = strdup(metric_names[i]);
+ printed = strdup(metric_name);
}
invalid = true;
continue;
}
- metric_events[i] = oc;
+ metric_events[i++] = oc;
oc->collect_stat = true;
}
metric_events[i] = NULL;
- free(metric_names);
if (invalid) {
free(metric_events);
counter->metric_events = NULL;
counter->metric_expr = NULL;
}
}
+ expr__ctx_clear(&ctx);
}

static double runtime_stat_avg(struct runtime_stat *st,
@@ -738,7 +751,10 @@ static void generic_metric(struct perf_stat_config *config,

expr__ctx_init(&pctx);
/* Must be first id entry */
- expr__add_id(&pctx, name, avg);
+ n = strdup(name);
+ if (!n)
+ return;
+ expr__add_id(&pctx, n, avg);
for (i = 0; metric_events[i]; i++) {
struct saved_value *v;
struct stats *stats;
@@ -814,8 +830,7 @@ static void generic_metric(struct perf_stat_config *config,
(metric_name ? metric_name : name) : "", 0);
}

- for (i = 1; i < pctx.num_ids; i++)
- zfree(&pctx.ids[i].name);
+ expr__ctx_clear(&pctx);
}

void perf_stat__print_shadow_stats(struct perf_stat_config *config,
--
2.26.2.645.ge9eca65c58-goog