1 files changed, 379 insertions, 0 deletions
diff --git a/tools/perf/util/cgroup.c b/tools/perf/util/cgroup.c
new file mode 100644
index 000000000..b81324a13
--- /dev/null
+++ b/tools/perf/util/cgroup.c
@@ -0,0 +1,379 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <subcmd/parse-options.h>
+#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>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <api/fs/fs.h>
+
+int nr_cgroups;
+
+static int open_cgroup(const char *name)
+{
+	char path[PATH_MAX + 1];
+	char mnt[PATH_MAX + 1];
+	int fd;
+
+
+	if (cgroupfs_find_mountpoint(mnt, PATH_MAX + 1, "perf_event"))
+		return -1;
+
+	scnprintf(path, PATH_MAX, "%s/%s", mnt, name);
+
+	fd = open(path, O_RDONLY);
+	if (fd == -1)
+		fprintf(stderr, "no access to cgroup %s\n", path);
+
+	return fd;
+}
+
+static struct cgroup *evlist__find_cgroup(struct evlist *evlist, const char *str)
+{
+	struct evsel *counter;
+	/*
+	 * check if cgrp is already defined, if so we reuse it
+	 */
+	evlist__for_each_entry(evlist, counter) {
+		if (!counter->cgrp)
+			continue;
+		if (!strcmp(counter->cgrp->name, str))
+			return cgroup__get(counter->cgrp);
+	}
+
+	return NULL;
+}
+
+static struct cgroup *cgroup__new(const char *name, bool do_open)
+{
+	struct cgroup *cgroup = zalloc(sizeof(*cgroup));
+
+	if (cgroup != NULL) {
+		refcount_set(&cgroup->refcnt, 1);
+
+		cgroup->name = strdup(name);
+		if (!cgroup->name)
+			goto out_err;
+
+		if (do_open) {
+			cgroup->fd = open_cgroup(name);
+			if (cgroup->fd == -1)
+				goto out_free_name;
+		} else {
+			cgroup->fd = -1;
+		}
+	}
+
+	return cgroup;
+
+out_free_name:
+	zfree(&cgroup->name);
+out_err:
+	free(cgroup);
+	return NULL;
+}
+
+struct cgroup *evlist__findnew_cgroup(struct evlist *evlist, const char *name)
+{
+	struct cgroup *cgroup = evlist__find_cgroup(evlist, name);
+
+	return cgroup ?: cgroup__new(name, true);
+}
+
+static int add_cgroup(struct evlist *evlist, const char *str)
+{
+	struct evsel *counter;
+	struct cgroup *cgrp = evlist__findnew_cgroup(evlist, str);
+	int n;
+
+	if (!cgrp)
+		return -1;
+	/*
+	 * find corresponding event
+	 * if add cgroup N, then need to find event N
+	 */
+	n = 0;
+	evlist__for_each_entry(evlist, counter) {
+		if (n == nr_cgroups)
+			goto found;
+		n++;
+	}
+
+	cgroup__put(cgrp);
+	return -1;
+found:
+	counter->cgrp = cgrp;
+	return 0;
+}
+
+static void cgroup__delete(struct cgroup *cgroup)
+{
+	if (cgroup->fd >= 0)
+		close(cgroup->fd);
+	zfree(&cgroup->name);
+	free(cgroup);
+}
+
+void cgroup__put(struct cgroup *cgrp)
+{
+	if (cgrp && refcount_dec_and_test(&cgrp->refcnt)) {
+		cgroup__delete(cgrp);
+	}
+}
+
+struct cgroup *cgroup__get(struct cgroup *cgroup)
+{
+       if (cgroup)
+		refcount_inc(&cgroup->refcnt);
+       return cgroup;
+}
+
+static void evsel__set_default_cgroup(struct evsel *evsel, struct cgroup *cgroup)
+{
+	if (evsel->cgrp == NULL)
+		evsel->cgrp = cgroup__get(cgroup);
+}
+
+void evlist__set_default_cgroup(struct evlist *evlist, struct cgroup *cgroup)
+{
+	struct evsel *evsel;
+
+	evlist__for_each_entry(evlist, evsel)
+		evsel__set_default_cgroup(evsel, cgroup);
+}
+
+int parse_cgroups(const struct option *opt, const char *str,
+		  int unset __maybe_unused)
+{
+	struct evlist *evlist = *(struct evlist **)opt->value;
+	struct evsel *counter;
+	struct cgroup *cgrp = NULL;
+	const char *p, *e, *eos = str + strlen(str);
+	char *s;
+	int ret, i;
+
+	if (list_empty(&evlist->core.entries)) {
+		fprintf(stderr, "must define events before cgroups\n");
+		return -1;
+	}
+
+	for (;;) {
+		p = strchr(str, ',');
+		e = p ? p : eos;
+
+		/* allow empty cgroups, i.e., skip */
+		if (e - str) {
+			/* termination added */
+			s = strndup(str, e - str);
+			if (!s)
+				return -1;
+			ret = add_cgroup(evlist, s);
+			free(s);
+			if (ret)
+				return -1;
+		}
+		/* nr_cgroups is increased een for empty cgroups */
+		nr_cgroups++;
+		if (!p)
+			break;
+		str = p+1;
+	}
+	/* for the case one cgroup combine to multiple events */
+	i = 0;
+	if (nr_cgroups == 1) {
+		evlist__for_each_entry(evlist, counter) {
+			if (i == 0)
+				cgrp = counter->cgrp;
+			else {
+				counter->cgrp = cgrp;
+				refcount_inc(&cgrp->refcnt);
+			}
+			i++;
+		}
+	}
+	return 0;
+}
+
+int evlist__expand_cgroup(struct evlist *evlist, const char *str,
+			  struct rblist *metric_events, bool open_cgroup)
+{
+	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;
+
+	if (evlist->core.nr_entries == 0) {
+		fprintf(stderr, "must define events before cgroups\n");
+		return -EINVAL;
+	}
+
+	orig_list = evlist__new();
+	tmp_list = evlist__new();
+	if (orig_list == NULL || tmp_list == NULL) {
+		fprintf(stderr, "memory allocation failed\n");
+		return -ENOMEM;
+	}
+
+	/* save original events and init evlist */
+	perf_evlist__splice_list_tail(orig_list, &evlist->core.entries);
+	evlist->core.nr_entries = 0;
+
+	if (metric_events) {
+		orig_metric_events = *metric_events;
+		rblist__init(metric_events);
+	} else {
+		rblist__init(&orig_metric_events);
+	}
+
+	for (;;) {
+		p = strchr(str, ',');
+		e = p ? p : eos;
+
+		/* allow empty cgroups, i.e., skip */
+		if (e - str) {
+			/* termination added */
+			char *name = strndup(str, e - str);
+			if (!name)
+				goto out_err;
+
+			cgrp = cgroup__new(name, open_cgroup);
+			free(name);
+			if (cgrp == NULL)
+				goto out_err;
+		} else {
+			cgrp = NULL;
+		}
+
+		leader = NULL;
+		evlist__for_each_entry(orig_list, pos) {
+			evsel = evsel__clone(pos);
+			if (evsel == NULL)
+				goto out_err;
+
+			cgroup__put(evsel->cgrp);
+			evsel->cgrp = cgroup__get(cgrp);
+
+			if (evsel__is_group_leader(pos))
+				leader = evsel;
+			evsel->leader = leader;
+
+			evlist__add(tmp_list, evsel);
+		}
+		/* cgroup__new() has a refcount, release it here */
+		cgroup__put(cgrp);
+		nr_cgroups++;
+
+		if (metric_events) {
+			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;
+
+		if (!p) {
+			ret = 0;
+			break;
+		}
+		str = p+1;
+	}
+
+out_err:
+	evlist__delete(orig_list);
+	evlist__delete(tmp_list);
+	rblist__exit(&orig_metric_events);
+
+	return ret;
+}
+
+static struct cgroup *__cgroup__findnew(struct rb_root *root, uint64_t id,
+					bool create, const char *path)
+{
+	struct rb_node **p = &root->rb_node;
+	struct rb_node *parent = NULL;
+	struct cgroup *cgrp;
+
+	while (*p != NULL) {
+		parent = *p;
+		cgrp = rb_entry(parent, struct cgroup, node);
+
+		if (cgrp->id == id)
+			return cgrp;
+
+		if (cgrp->id < id)
+			p = &(*p)->rb_left;
+		else
+			p = &(*p)->rb_right;
+	}
+
+	if (!create)
+		return NULL;
+
+	cgrp = malloc(sizeof(*cgrp));
+	if (cgrp == NULL)
+		return NULL;
+
+	cgrp->name = strdup(path);
+	if (cgrp->name == NULL) {
+		free(cgrp);
+		return NULL;
+	}
+
+	cgrp->fd = -1;
+	cgrp->id = id;
+	refcount_set(&cgrp->refcnt, 1);
+
+	rb_link_node(&cgrp->node, parent, p);
+	rb_insert_color(&cgrp->node, root);
+
+	return cgrp;
+}
+
+struct cgroup *cgroup__findnew(struct perf_env *env, uint64_t id,
+			       const char *path)
+{
+	struct cgroup *cgrp;
+
+	down_write(&env->cgroups.lock);
+	cgrp = __cgroup__findnew(&env->cgroups.tree, id, true, path);
+	up_write(&env->cgroups.lock);
+	return cgrp;
+}
+
+struct cgroup *cgroup__find(struct perf_env *env, uint64_t id)
+{
+	struct cgroup *cgrp;
+
+	down_read(&env->cgroups.lock);
+	cgrp = __cgroup__findnew(&env->cgroups.tree, id, false, NULL);
+	up_read(&env->cgroups.lock);
+	return cgrp;
+}
+
+void perf_env__purge_cgroups(struct perf_env *env)
+{
+	struct rb_node *node;
+	struct cgroup *cgrp;
+
+	down_write(&env->cgroups.lock);
+	while (!RB_EMPTY_ROOT(&env->cgroups.tree)) {
+		node = rb_first(&env->cgroups.tree);
+		cgrp = rb_entry(node, struct cgroup, node);
+
+		rb_erase(node, &env->cgroups.tree);
+		cgroup__put(cgrp);
+	}
+	up_write(&env->cgroups.lock);
+}