diff options
Diffstat (limited to 'kernel/cgroup/cgroup.c')
| -rw-r--r-- | kernel/cgroup/cgroup.c | 157 |
1 files changed, 155 insertions, 2 deletions
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 00f5b358aeac..0b1ffe147f24 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -142,12 +142,14 @@ static struct static_key_true *cgroup_subsys_on_dfl_key[] = { }; #undef SUBSYS +static DEFINE_PER_CPU(struct cgroup_cpu_stat, cgrp_dfl_root_cpu_stat); + /* * The default hierarchy, reserved for the subsystems that are otherwise * unattached - it never has more than a single cgroup, and all tasks are * part of that cgroup. */ -struct cgroup_root cgrp_dfl_root; +struct cgroup_root cgrp_dfl_root = { .cgrp.cpu_stat = &cgrp_dfl_root_cpu_stat }; EXPORT_SYMBOL_GPL(cgrp_dfl_root); /* @@ -462,6 +464,28 @@ static struct cgroup_subsys_state *cgroup_css(struct cgroup *cgrp, } /** + * cgroup_tryget_css - try to get a cgroup's css for the specified subsystem + * @cgrp: the cgroup of interest + * @ss: the subsystem of interest + * + * Find and get @cgrp's css assocaited with @ss. If the css doesn't exist + * or is offline, %NULL is returned. + */ +static struct cgroup_subsys_state *cgroup_tryget_css(struct cgroup *cgrp, + struct cgroup_subsys *ss) +{ + struct cgroup_subsys_state *css; + + rcu_read_lock(); + css = cgroup_css(cgrp, ss); + if (!css || !css_tryget_online(css)) + css = NULL; + rcu_read_unlock(); + + return css; +} + +/** * cgroup_e_css - obtain a cgroup's effective css for the specified subsystem * @cgrp: the cgroup of interest * @ss: the subsystem of interest (%NULL returns @cgrp->self) @@ -647,6 +671,14 @@ struct css_set init_css_set = { .cgrp_links = LIST_HEAD_INIT(init_css_set.cgrp_links), .mg_preload_node = LIST_HEAD_INIT(init_css_set.mg_preload_node), .mg_node = LIST_HEAD_INIT(init_css_set.mg_node), + + /* + * The following field is re-initialized when this cset gets linked + * in cgroup_init(). However, let's initialize the field + * statically too so that the default cgroup can be accessed safely + * early during boot. + */ + .dfl_cgrp = &cgrp_dfl_root.cgrp, }; static int css_set_count = 1; /* 1 for init_css_set */ @@ -3315,6 +3347,37 @@ static int cgroup_stat_show(struct seq_file *seq, void *v) return 0; } +static int __maybe_unused cgroup_extra_stat_show(struct seq_file *seq, + struct cgroup *cgrp, int ssid) +{ + struct cgroup_subsys *ss = cgroup_subsys[ssid]; + struct cgroup_subsys_state *css; + int ret; + + if (!ss->css_extra_stat_show) + return 0; + + css = cgroup_tryget_css(cgrp, ss); + if (!css) + return 0; + + ret = ss->css_extra_stat_show(seq, css); + css_put(css); + return ret; +} + +static int cpu_stat_show(struct seq_file *seq, void *v) +{ + struct cgroup __maybe_unused *cgrp = seq_css(seq)->cgroup; + int ret = 0; + + cgroup_stat_show_cputime(seq); +#ifdef CONFIG_CGROUP_SCHED + ret = cgroup_extra_stat_show(seq, cgrp, cpu_cgrp_id); +#endif + return ret; +} + static int cgroup_file_open(struct kernfs_open_file *of) { struct cftype *cft = of->kn->priv; @@ -4422,6 +4485,11 @@ static struct cftype cgroup_base_files[] = { .name = "cgroup.stat", .seq_show = cgroup_stat_show, }, + { + .name = "cpu.stat", + .flags = CFTYPE_NOT_ON_ROOT, + .seq_show = cpu_stat_show, + }, { } /* terminate */ }; @@ -4482,6 +4550,8 @@ static void css_free_work_fn(struct work_struct *work) */ cgroup_put(cgroup_parent(cgrp)); kernfs_put(cgrp->kn); + if (cgroup_on_dfl(cgrp)) + cgroup_stat_exit(cgrp); kfree(cgrp); } else { /* @@ -4526,6 +4596,9 @@ static void css_release_work_fn(struct work_struct *work) /* cgroup release path */ trace_cgroup_release(cgrp); + if (cgroup_on_dfl(cgrp)) + cgroup_stat_flush(cgrp); + for (tcgrp = cgroup_parent(cgrp); tcgrp; tcgrp = cgroup_parent(tcgrp)) tcgrp->nr_dying_descendants--; @@ -4709,6 +4782,12 @@ static struct cgroup *cgroup_create(struct cgroup *parent) if (ret) goto out_free_cgrp; + if (cgroup_on_dfl(parent)) { + ret = cgroup_stat_init(cgrp); + if (ret) + goto out_cancel_ref; + } + /* * Temporarily set the pointer to NULL, so idr_find() won't return * a half-baked cgroup. @@ -4716,7 +4795,7 @@ static struct cgroup *cgroup_create(struct cgroup *parent) cgrp->id = cgroup_idr_alloc(&root->cgroup_idr, NULL, 2, 0, GFP_KERNEL); if (cgrp->id < 0) { ret = -ENOMEM; - goto out_cancel_ref; + goto out_stat_exit; } init_cgroup_housekeeping(cgrp); @@ -4767,6 +4846,9 @@ static struct cgroup *cgroup_create(struct cgroup *parent) out_idr_free: cgroup_idr_remove(&root->cgroup_idr, cgrp->id); +out_stat_exit: + if (cgroup_on_dfl(parent)) + cgroup_stat_exit(cgrp); out_cancel_ref: percpu_ref_exit(&cgrp->self.refcnt); out_free_cgrp: @@ -5161,6 +5243,8 @@ int __init cgroup_init(void) BUG_ON(cgroup_init_cftypes(NULL, cgroup_base_files)); BUG_ON(cgroup_init_cftypes(NULL, cgroup1_base_files)); + cgroup_stat_boot(); + /* * The latency of the synchronize_sched() is too high for cgroups, * avoid it at the cost of forcing all readers into the slow path. @@ -5780,3 +5864,72 @@ int cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr, return ret; } #endif /* CONFIG_CGROUP_BPF */ + +#ifdef CONFIG_SYSFS +static ssize_t show_delegatable_files(struct cftype *files, char *buf, + ssize_t size, const char *prefix) +{ + struct cftype *cft; + ssize_t ret = 0; + + for (cft = files; cft && cft->name[0] != '\0'; cft++) { + if (!(cft->flags & CFTYPE_NS_DELEGATABLE)) + continue; + + if (prefix) + ret += snprintf(buf + ret, size - ret, "%s.", prefix); + + ret += snprintf(buf + ret, size - ret, "%s\n", cft->name); + + if (unlikely(ret >= size)) { + WARN_ON(1); + break; + } + } + + return ret; +} + +static ssize_t delegate_show(struct kobject *kobj, struct kobj_attribute *attr, + char *buf) +{ + struct cgroup_subsys *ss; + int ssid; + ssize_t ret = 0; + + ret = show_delegatable_files(cgroup_base_files, buf, PAGE_SIZE - ret, + NULL); + + for_each_subsys(ss, ssid) + ret += show_delegatable_files(ss->dfl_cftypes, buf + ret, + PAGE_SIZE - ret, + cgroup_subsys_name[ssid]); + + return ret; +} +static struct kobj_attribute cgroup_delegate_attr = __ATTR_RO(delegate); + +static ssize_t features_show(struct kobject *kobj, struct kobj_attribute *attr, + char *buf) +{ + return snprintf(buf, PAGE_SIZE, "nsdelegate\n"); +} +static struct kobj_attribute cgroup_features_attr = __ATTR_RO(features); + +static struct attribute *cgroup_sysfs_attrs[] = { + &cgroup_delegate_attr.attr, + &cgroup_features_attr.attr, + NULL, +}; + +static const struct attribute_group cgroup_sysfs_attr_group = { + .attrs = cgroup_sysfs_attrs, + .name = "cgroup", +}; + +static int __init cgroup_sysfs_init(void) +{ + return sysfs_create_group(kernel_kobj, &cgroup_sysfs_attr_group); +} +subsys_initcall(cgroup_sysfs_init); +#endif /* CONFIG_SYSFS */ |