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-rw-r--r--tools/perf/util/cgroup.c646
1 files changed, 646 insertions, 0 deletions
diff --git a/tools/perf/util/cgroup.c b/tools/perf/util/cgroup.c
new file mode 100644
index 000000000..c7be16a79
--- /dev/null
+++ b/tools/perf/util/cgroup.c
@@ -0,0 +1,646 @@
+// 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 <sys/statfs.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <api/fs/fs.h>
+#include <ftw.h>
+#include <regex.h>
+
+int nr_cgroups;
+bool cgrp_event_expanded;
+
+/* used to match cgroup name with patterns */
+struct cgroup_name {
+ struct list_head list;
+ bool used;
+ char name[];
+};
+static LIST_HEAD(cgroup_list);
+
+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;
+}
+
+#ifdef HAVE_FILE_HANDLE
+static u64 __read_cgroup_id(const char *path)
+{
+ struct {
+ struct file_handle fh;
+ uint64_t cgroup_id;
+ } handle;
+ int mount_id;
+
+ handle.fh.handle_bytes = sizeof(handle.cgroup_id);
+ if (name_to_handle_at(AT_FDCWD, path, &handle.fh, &mount_id, 0) < 0)
+ return -1ULL;
+
+ return handle.cgroup_id;
+}
+
+int read_cgroup_id(struct cgroup *cgrp)
+{
+ char path[PATH_MAX + 1];
+ char mnt[PATH_MAX + 1];
+
+ if (cgroupfs_find_mountpoint(mnt, PATH_MAX + 1, "perf_event"))
+ return -1;
+
+ scnprintf(path, PATH_MAX, "%s/%s", mnt, cgrp->name);
+
+ cgrp->id = __read_cgroup_id(path);
+ return 0;
+}
+#else
+static inline u64 __read_cgroup_id(const char *path __maybe_unused) { return -1ULL; }
+#endif /* HAVE_FILE_HANDLE */
+
+#ifndef CGROUP2_SUPER_MAGIC
+#define CGROUP2_SUPER_MAGIC 0x63677270
+#endif
+
+int cgroup_is_v2(const char *subsys)
+{
+ char mnt[PATH_MAX + 1];
+ struct statfs stbuf;
+
+ if (cgroupfs_find_mountpoint(mnt, PATH_MAX + 1, subsys))
+ return -1;
+
+ if (statfs(mnt, &stbuf) < 0)
+ return -1;
+
+ return (stbuf.f_type == CGROUP2_SUPER_MAGIC);
+}
+
+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;
+}
+
+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);
+}
+
+/* helper function for ftw() in match_cgroups and list_cgroups */
+static int add_cgroup_name(const char *fpath, const struct stat *sb __maybe_unused,
+ int typeflag, struct FTW *ftwbuf __maybe_unused)
+{
+ struct cgroup_name *cn;
+
+ if (typeflag != FTW_D)
+ return 0;
+
+ cn = malloc(sizeof(*cn) + strlen(fpath) + 1);
+ if (cn == NULL)
+ return -1;
+
+ cn->used = false;
+ strcpy(cn->name, fpath);
+
+ list_add_tail(&cn->list, &cgroup_list);
+ return 0;
+}
+
+static int check_and_add_cgroup_name(const char *fpath)
+{
+ struct cgroup_name *cn;
+
+ list_for_each_entry(cn, &cgroup_list, list) {
+ if (!strcmp(cn->name, fpath))
+ return 0;
+ }
+
+ /* pretend if it's added by ftw() */
+ return add_cgroup_name(fpath, NULL, FTW_D, NULL);
+}
+
+static void release_cgroup_list(void)
+{
+ struct cgroup_name *cn;
+
+ while (!list_empty(&cgroup_list)) {
+ cn = list_first_entry(&cgroup_list, struct cgroup_name, list);
+ list_del(&cn->list);
+ free(cn);
+ }
+}
+
+/* collect given cgroups only */
+static int list_cgroups(const char *str)
+{
+ const char *p, *e, *eos = str + strlen(str);
+ struct cgroup_name *cn;
+ char *s;
+
+ /* use given name as is when no regex is given */
+ for (;;) {
+ p = strchr(str, ',');
+ e = p ? p : eos;
+
+ if (e - str) {
+ int ret;
+
+ s = strndup(str, e - str);
+ if (!s)
+ return -1;
+
+ ret = check_and_add_cgroup_name(s);
+ free(s);
+ if (ret < 0)
+ return -1;
+ } else {
+ if (check_and_add_cgroup_name("/") < 0)
+ return -1;
+ }
+
+ if (!p)
+ break;
+ str = p+1;
+ }
+
+ /* these groups will be used */
+ list_for_each_entry(cn, &cgroup_list, list)
+ cn->used = true;
+
+ return 0;
+}
+
+/* collect all cgroups first and then match with the pattern */
+static int match_cgroups(const char *str)
+{
+ char mnt[PATH_MAX];
+ const char *p, *e, *eos = str + strlen(str);
+ struct cgroup_name *cn;
+ regex_t reg;
+ int prefix_len;
+ char *s;
+
+ if (cgroupfs_find_mountpoint(mnt, sizeof(mnt), "perf_event"))
+ return -1;
+
+ /* cgroup_name will have a full path, skip the root directory */
+ prefix_len = strlen(mnt);
+
+ /* collect all cgroups in the cgroup_list */
+ if (nftw(mnt, add_cgroup_name, 20, 0) < 0)
+ 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;
+ if (regcomp(&reg, s, REG_NOSUB)) {
+ free(s);
+ return -1;
+ }
+
+ /* check cgroup name with the pattern */
+ list_for_each_entry(cn, &cgroup_list, list) {
+ char *name = cn->name + prefix_len;
+
+ if (name[0] == '/' && name[1])
+ name++;
+ if (!regexec(&reg, name, 0, NULL, 0))
+ cn->used = true;
+ }
+ regfree(&reg);
+ free(s);
+ } else {
+ /* first entry to root cgroup */
+ cn = list_first_entry(&cgroup_list, struct cgroup_name,
+ list);
+ cn->used = true;
+ }
+
+ if (!p)
+ break;
+ str = p+1;
+ }
+ return prefix_len;
+}
+
+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(evlist)->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;
+}
+
+static bool has_pattern_string(const char *str)
+{
+ return !!strpbrk(str, "{}[]()|*+?^$");
+}
+
+int evlist__expand_cgroup(struct evlist *evlist, const char *str, bool open_cgroup)
+{
+ struct evlist *orig_list, *tmp_list;
+ struct rblist orig_metric_events;
+ struct cgroup *cgrp = NULL;
+ struct cgroup_name *cn;
+ int ret = -1;
+ int prefix_len;
+
+ if (evlist__nr_entries(evlist) == 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 */
+ evlist__splice_list_tail(orig_list, &evlist__core(evlist)->entries);
+ evlist__core(evlist)->nr_entries = 0;
+
+ orig_metric_events = *evlist__metric_events(evlist);
+ metricgroup__rblist_init(evlist__metric_events(evlist));
+
+ if (has_pattern_string(str))
+ prefix_len = match_cgroups(str);
+ else
+ prefix_len = list_cgroups(str);
+
+ if (prefix_len < 0)
+ goto out_err;
+
+ list_for_each_entry(cn, &cgroup_list, list) {
+ struct evsel *pos;
+ char *name;
+
+ if (!cn->used)
+ continue;
+
+ /* cgroup_name might have a full path, skip the prefix */
+ name = cn->name + prefix_len;
+ if (name[0] == '/' && name[1])
+ name++;
+
+ /* the cgroup can go away in the meantime */
+ cgrp = cgroup__new(name, open_cgroup);
+ if (cgrp == NULL)
+ continue;
+
+ /* copy the list and set to the new cgroup. */
+ evlist__for_each_entry(orig_list, pos) {
+ struct evsel *evsel = evsel__clone(pos);
+
+ if (evsel == NULL)
+ goto out_err;
+
+ /* stash the copy during the copying. */
+ pos->priv = evsel;
+ cgroup__put(evsel->cgrp);
+ evsel->cgrp = cgroup__get(cgrp);
+
+ evlist__add(tmp_list, evsel);
+ }
+ /* update leader information using stashed pointer to copy. */
+ evlist__for_each_entry(orig_list, pos) {
+ struct evsel *evsel = pos->priv;
+
+ if (evsel__leader(pos))
+ evsel__set_leader(evsel, evsel__leader(pos)->priv);
+
+ if (pos->metric_leader)
+ evsel->metric_leader = pos->metric_leader->priv;
+
+ if (pos->first_wildcard_match)
+ evsel->first_wildcard_match = pos->first_wildcard_match->priv;
+ }
+ /* the stashed copy is no longer used. */
+ evlist__for_each_entry(orig_list, pos)
+ pos->priv = NULL;
+
+ /* cgroup__new() has a refcount, release it here */
+ cgroup__put(cgrp);
+ nr_cgroups++;
+
+ if (metricgroup__copy_metric_events(tmp_list, cgrp,
+ evlist__metric_events(evlist),
+ &orig_metric_events) < 0)
+ goto out_err;
+
+ evlist__splice_list_tail(evlist, &evlist__core(tmp_list)->entries);
+ evlist__core(tmp_list)->nr_entries = 0;
+ }
+
+ if (list_empty(&evlist__core(evlist)->entries)) {
+ fprintf(stderr, "no cgroup matched: %s\n", str);
+ goto out_err;
+ }
+
+ ret = 0;
+ cgrp_event_expanded = true;
+
+out_err:
+ evlist__put(orig_list);
+ evlist__put(tmp_list);
+ metricgroup__rblist_exit(&orig_metric_events);
+ release_cgroup_list();
+
+ 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 rb_root *root, uint64_t id)
+{
+ return __cgroup__findnew(root, id, /*create=*/false, /*path=*/NULL);
+}
+
+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);
+}
+
+void read_all_cgroups(struct rb_root *root)
+{
+ char mnt[PATH_MAX];
+ struct cgroup_name *cn;
+ int prefix_len;
+
+ if (cgroupfs_find_mountpoint(mnt, sizeof(mnt), "perf_event"))
+ return;
+
+ /* cgroup_name will have a full path, skip the root directory */
+ prefix_len = strlen(mnt);
+
+ /* collect all cgroups in the cgroup_list */
+ if (nftw(mnt, add_cgroup_name, 20, 0) < 0)
+ return;
+
+ list_for_each_entry(cn, &cgroup_list, list) {
+ const char *name;
+ u64 cgrp_id;
+
+ /* cgroup_name might have a full path, skip the prefix */
+ name = cn->name + prefix_len;
+ if (name[0] == '\0')
+ name = "/";
+
+ cgrp_id = __read_cgroup_id(cn->name);
+ __cgroup__findnew(root, cgrp_id, /*create=*/true, name);
+ }
+
+ release_cgroup_list();
+}
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