[PATCH 3/5] perf tools: Copy metric events properly when expand cgroups

From: Namhyung Kim
Date: Tue Sep 22 2020 - 22:00:07 EST

The metricgroup__copy_metric_events() is to handle metrics events when
expanding event for cgroups. As the metric events keep pointers to
evsel, it should be refreshed when events are cloned during the
operation.

The perf_stat__collect_metric_expr() is also called in case an event
has a metric directly.

During the copy, it references evsel by index as the evlist now has
cloned evsels for the given cgroup.

Cc: John Garry <john.garry@xxxxxxxxxx>
Cc: Kajol Jain <kjain@xxxxxxxxxxxxx>
Cc: Ian Rogers <irogers@xxxxxxxxxx>
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/builtin-stat.c | 3 +-
tools/perf/util/cgroup.c | 15 ++++++-
tools/perf/util/cgroup.h | 4 +-
tools/perf/util/evlist.c | 11 +++++
tools/perf/util/evlist.h | 1 +
tools/perf/util/metricgroup.c | 85 +++++++++++++++++++++++++++++++++++
tools/perf/util/metricgroup.h | 6 +++
7 files changed, 122 insertions(+), 3 deletions(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 23abf14b6e16..66a33d97192d 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -2255,7 +2255,8 @@ int cmd_stat(int argc, const char **argv)
goto out;
}

- if (evlist__expand_cgroup(evsel_list, stat_config.cgroup_list) < 0)
+ if (evlist__expand_cgroup(evsel_list, stat_config.cgroup_list,
+ &stat_config.metric_events) < 0)
goto out;
}

diff --git a/tools/perf/util/cgroup.c b/tools/perf/util/cgroup.c
index 8b6a4fa49082..dcd18ef268a1 100644
--- a/tools/perf/util/cgroup.c
+++ b/tools/perf/util/cgroup.c
@@ -3,6 +3,9 @@
#include "evsel.h"
#include "cgroup.h"
#include "evlist.h"
+#include "rblist.h"
+#include "metricgroup.h"
+#include "stat.h"
#include <linux/zalloc.h>
#include <sys/types.h>
#include <sys/stat.h>
@@ -193,10 +196,12 @@ int parse_cgroups(const struct option *opt, const char *str,
return 0;
}

-int evlist__expand_cgroup(struct evlist *evlist, const char *str)
+int evlist__expand_cgroup(struct evlist *evlist, const char *str,
+ struct rblist *metric_events)
{
struct evlist *orig_list, *tmp_list;
struct evsel *pos, *evsel, *leader;
+ struct rblist orig_metric_events;
struct cgroup *cgrp = NULL;
const char *p, *e, *eos = str + strlen(str);
int ret = -1;
@@ -216,6 +221,8 @@ int evlist__expand_cgroup(struct evlist *evlist, const char *str)
/* save original events and init evlist */
perf_evlist__splice_list_tail(orig_list, &evlist->core.entries);
evlist->core.nr_entries = 0;
+ orig_metric_events = *metric_events;
+ rblist__init(metric_events);

for (;;) {
p = strchr(str, ',');
@@ -255,6 +262,11 @@ int evlist__expand_cgroup(struct evlist *evlist, const char *str)
cgroup__put(cgrp);
nr_cgroups++;

+ perf_stat__collect_metric_expr(tmp_list);
+ if (metricgroup__copy_metric_events(tmp_list, cgrp, metric_events,
+ &orig_metric_events) < 0)
+ break;
+
perf_evlist__splice_list_tail(evlist, &tmp_list->core.entries);
tmp_list->core.nr_entries = 0;

@@ -268,6 +280,7 @@ int evlist__expand_cgroup(struct evlist *evlist, const char *str)
out_err:
evlist__delete(orig_list);
evlist__delete(tmp_list);
+ rblist__exit(&orig_metric_events);

return ret;
}
diff --git a/tools/perf/util/cgroup.h b/tools/perf/util/cgroup.h
index 32893018296f..eea6df8ee373 100644
--- a/tools/perf/util/cgroup.h
+++ b/tools/perf/util/cgroup.h
@@ -22,9 +22,11 @@ struct cgroup *cgroup__get(struct cgroup *cgroup);
void cgroup__put(struct cgroup *cgroup);

struct evlist;
+struct rblist;

struct cgroup *evlist__findnew_cgroup(struct evlist *evlist, const char *name);
-int evlist__expand_cgroup(struct evlist *evlist, const char *cgroups);
+int evlist__expand_cgroup(struct evlist *evlist, const char *cgroups,
+ struct rblist *metric_events);

void evlist__set_default_cgroup(struct evlist *evlist, struct cgroup *cgroup);

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index ee7b576d3b12..aae79b2b5041 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1964,3 +1964,14 @@ int evlist__ctlfd_process(struct evlist *evlist, enum evlist_ctl_cmd *cmd)

return err;
}
+
+struct evsel *evlist__find_evsel(struct evlist *evlist, int idx)
+{
+ struct evsel *evsel;
+
+ evlist__for_each_entry(evlist, evsel) {
+ if (evsel->idx == idx)
+ return evsel;
+ }
+ return NULL;
+}
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index bc38a53f6a1a..e1a450322bc5 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -386,4 +386,5 @@ int evlist__ctlfd_ack(struct evlist *evlist);
#define EVLIST_ENABLED_MSG "Events enabled\n"
#define EVLIST_DISABLED_MSG "Events disabled\n"

+struct evsel *evlist__find_evsel(struct evlist *evlist, int idx);
#endif /* __PERF_EVLIST_H */
diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index d03bac65a3c2..14e8f13e07f7 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -24,6 +24,7 @@
#include <api/fs/fs.h>
#include "util.h"
#include <asm/bug.h>
+#include "cgroup.h"

struct metric_event *metricgroup__lookup(struct rblist *metric_events,
struct evsel *evsel,
@@ -1105,3 +1106,87 @@ bool metricgroup__has_metric(const char *metric)
}
return false;
}
+
+int metricgroup__copy_metric_events(struct evlist *evlist, struct cgroup *cgrp,
+ struct rblist *new_metric_events,
+ struct rblist *old_metric_events)
+{
+ unsigned i;
+
+ for (i = 0; i < rblist__nr_entries(old_metric_events); i++) {
+ struct rb_node *nd;
+ struct metric_event *old_me, *new_me;
+ struct metric_expr *old_expr, *new_expr;
+ struct evsel *evsel;
+ size_t alloc_size;
+ int idx, nr;
+
+ nd = rblist__entry(old_metric_events, i);
+ old_me = container_of(nd, struct metric_event, nd);
+
+ evsel = evlist__find_evsel(evlist, old_me->evsel->idx);
+ if (!evsel)
+ return -EINVAL;
+ new_me = metricgroup__lookup(new_metric_events, evsel, true);
+ if (!new_me)
+ return -ENOMEM;
+
+ pr_debug("copying metric event for cgroup '%s': %s (idx=%d)\n",
+ cgrp ? cgrp->name : "root", evsel->name, evsel->idx);
+
+ list_for_each_entry(old_expr, &old_me->head, nd) {
+ new_expr = malloc(sizeof(*new_expr));
+ if (!new_expr)
+ return -ENOMEM;
+
+ new_expr->metric_expr = old_expr->metric_expr;
+ new_expr->metric_name = old_expr->metric_name;
+ new_expr->metric_unit = old_expr->metric_unit;
+ new_expr->runtime = old_expr->runtime;
+
+ if (old_expr->metric_refs) {
+ /* calculate number of metric_events */
+ for (nr = 0; old_expr->metric_refs[nr].metric_name; nr++)
+ continue;
+ alloc_size = sizeof(*new_expr->metric_refs);
+ new_expr->metric_refs = calloc(nr + 1, alloc_size);
+ if (!new_expr->metric_refs) {
+ free(new_expr);
+ return -ENOMEM;
+ }
+
+ memcpy(new_expr->metric_refs, old_expr->metric_refs,
+ nr * alloc_size);
+ } else {
+ new_expr->metric_refs = NULL;
+ }
+
+ /* calculate number of metric_events */
+ for (nr = 0; old_expr->metric_events[nr]; nr++)
+ continue;
+ alloc_size = sizeof(*new_expr->metric_events);
+ new_expr->metric_events = calloc(nr + 1, alloc_size);
+ if (!new_expr->metric_events) {
+ free(new_expr->metric_refs);
+ free(new_expr);
+ return -ENOMEM;
+ }
+
+ /* copy evsel in the same position */
+ for (idx = 0; idx < nr; idx++) {
+ evsel = old_expr->metric_events[idx];
+ evsel = evlist__find_evsel(evlist, evsel->idx);
+ if (evsel == NULL) {
+ free(new_expr->metric_events);
+ free(new_expr->metric_refs);
+ free(new_expr);
+ return -EINVAL;
+ }
+ new_expr->metric_events[idx] = evsel;
+ }
+
+ list_add(&new_expr->nd, &new_me->head);
+ }
+ }
+ return 0;
+}
diff --git a/tools/perf/util/metricgroup.h b/tools/perf/util/metricgroup.h
index 491a5d78252d..ed1b9392e624 100644
--- a/tools/perf/util/metricgroup.h
+++ b/tools/perf/util/metricgroup.h
@@ -7,11 +7,13 @@
#include <stdbool.h>
#include "pmu-events/pmu-events.h"

+struct evlist;
struct evsel;
struct evlist;
struct option;
struct rblist;
struct pmu_events_map;
+struct cgroup;

struct metric_event {
struct rb_node nd;
@@ -55,4 +57,8 @@ void metricgroup__print(bool metrics, bool groups, char *filter,
bool metricgroup__has_metric(const char *metric);
int arch_get_runtimeparam(struct pmu_event *pe __maybe_unused);
void metricgroup__rblist_exit(struct rblist *metric_events);
+
+int metricgroup__copy_metric_events(struct evlist *evlist, struct cgroup *cgrp,
+ struct rblist *new_metric_events,
+ struct rblist *old_metric_events);
#endif
--
2.28.0.681.g6f77f65b4e-goog