diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/helpers.c | 2 | ||||
| -rw-r--r-- | kernel/bpf/local_storage.c | 2 | ||||
| -rw-r--r-- | kernel/cgroup/cgroup-internal.h | 5 | ||||
| -rw-r--r-- | kernel/cgroup/cgroup-v1.c | 5 | ||||
| -rw-r--r-- | kernel/cgroup/cgroup.c | 325 | ||||
| -rw-r--r-- | kernel/cgroup/cpuset.c | 2 | ||||
| -rw-r--r-- | kernel/cgroup/freezer.c | 9 | ||||
| -rw-r--r-- | kernel/cgroup/pids.c | 11 | ||||
| -rw-r--r-- | kernel/cgroup/rstat.c | 46 | ||||
| -rw-r--r-- | kernel/trace/blktrace.c | 84 |
10 files changed, 196 insertions, 295 deletions
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 5e28718928ca..cada974c9f4e 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -317,7 +317,7 @@ BPF_CALL_0(bpf_get_current_cgroup_id) { struct cgroup *cgrp = task_dfl_cgroup(current); - return cgrp->kn->id.id; + return cgroup_id(cgrp); } const struct bpf_func_proto bpf_get_current_cgroup_id_proto = { diff --git a/kernel/bpf/local_storage.c b/kernel/bpf/local_storage.c index addd6fdceec8..2ba750725cb2 100644 --- a/kernel/bpf/local_storage.c +++ b/kernel/bpf/local_storage.c @@ -569,7 +569,7 @@ void bpf_cgroup_storage_link(struct bpf_cgroup_storage *storage, return; storage->key.attach_type = type; - storage->key.cgroup_inode_id = cgroup->kn->id.id; + storage->key.cgroup_inode_id = cgroup_id(cgroup); map = storage->map; diff --git a/kernel/cgroup/cgroup-internal.h b/kernel/cgroup/cgroup-internal.h index 809e34a3c017..90d1710fef6c 100644 --- a/kernel/cgroup/cgroup-internal.h +++ b/kernel/cgroup/cgroup-internal.h @@ -231,9 +231,10 @@ int cgroup_migrate(struct task_struct *leader, bool threadgroup, int cgroup_attach_task(struct cgroup *dst_cgrp, struct task_struct *leader, bool threadgroup); -struct task_struct *cgroup_procs_write_start(char *buf, bool threadgroup) +struct task_struct *cgroup_procs_write_start(char *buf, bool threadgroup, + bool *locked) __acquires(&cgroup_threadgroup_rwsem); -void cgroup_procs_write_finish(struct task_struct *task) +void cgroup_procs_write_finish(struct task_struct *task, bool locked) __releases(&cgroup_threadgroup_rwsem); void cgroup_lock_and_drain_offline(struct cgroup *cgrp); diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c index 7f83f4121d8d..09f3a413f6f8 100644 --- a/kernel/cgroup/cgroup-v1.c +++ b/kernel/cgroup/cgroup-v1.c @@ -495,12 +495,13 @@ static ssize_t __cgroup1_procs_write(struct kernfs_open_file *of, struct task_struct *task; const struct cred *cred, *tcred; ssize_t ret; + bool locked; cgrp = cgroup_kn_lock_live(of->kn, false); if (!cgrp) return -ENODEV; - task = cgroup_procs_write_start(buf, threadgroup); + task = cgroup_procs_write_start(buf, threadgroup, &locked); ret = PTR_ERR_OR_ZERO(task); if (ret) goto out_unlock; @@ -522,7 +523,7 @@ static ssize_t __cgroup1_procs_write(struct kernfs_open_file *of, ret = cgroup_attach_task(cgrp, task, threadgroup); out_finish: - cgroup_procs_write_finish(task); + cgroup_procs_write_finish(task, locked); out_unlock: cgroup_kn_unlock(of->kn); diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index ef4242e5d4bc..735af8f15f95 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -899,8 +899,7 @@ static void css_set_move_task(struct task_struct *task, /* * We are synchronized through cgroup_threadgroup_rwsem * against PF_EXITING setting such that we can't race - * against cgroup_exit() changing the css_set to - * init_css_set and dropping the old one. + * against cgroup_exit()/cgroup_free() dropping the css_set. */ WARN_ON_ONCE(task->flags & PF_EXITING); @@ -1309,10 +1308,7 @@ static void cgroup_exit_root_id(struct cgroup_root *root) void cgroup_free_root(struct cgroup_root *root) { - if (root) { - idr_destroy(&root->cgroup_idr); - kfree(root); - } + kfree(root); } static void cgroup_destroy_root(struct cgroup_root *root) @@ -1374,6 +1370,8 @@ current_cgns_cgroup_from_root(struct cgroup_root *root) cset = current->nsproxy->cgroup_ns->root_cset; if (cset == &init_css_set) { res = &root->cgrp; + } else if (root == &cgrp_dfl_root) { + res = cset->dfl_cgrp; } else { struct cgrp_cset_link *link; @@ -1430,9 +1428,8 @@ struct cgroup *task_cgroup_from_root(struct task_struct *task, struct cgroup_root *root) { /* - * No need to lock the task - since we hold cgroup_mutex the - * task can't change groups, so the only thing that can happen - * is that it exits and its css is set back to init_css_set. + * No need to lock the task - since we hold css_set_lock the + * task can't change groups. */ return cset_cgroup_from_root(task_css_set(task), root); } @@ -1883,65 +1880,6 @@ static int cgroup_reconfigure(struct fs_context *fc) return 0; } -/* - * To reduce the fork() overhead for systems that are not actually using - * their cgroups capability, we don't maintain the lists running through - * each css_set to its tasks until we see the list actually used - in other - * words after the first mount. - */ -static bool use_task_css_set_links __read_mostly; - -void cgroup_enable_task_cg_lists(void) -{ - struct task_struct *p, *g; - - /* - * We need tasklist_lock because RCU is not safe against - * while_each_thread(). Besides, a forking task that has passed - * cgroup_post_fork() without seeing use_task_css_set_links = 1 - * is not guaranteed to have its child immediately visible in the - * tasklist if we walk through it with RCU. - */ - read_lock(&tasklist_lock); - spin_lock_irq(&css_set_lock); - - if (use_task_css_set_links) - goto out_unlock; - - use_task_css_set_links = true; - - do_each_thread(g, p) { - WARN_ON_ONCE(!list_empty(&p->cg_list) || - task_css_set(p) != &init_css_set); - - /* - * We should check if the process is exiting, otherwise - * it will race with cgroup_exit() in that the list - * entry won't be deleted though the process has exited. - * Do it while holding siglock so that we don't end up - * racing against cgroup_exit(). - * - * Interrupts were already disabled while acquiring - * the css_set_lock, so we do not need to disable it - * again when acquiring the sighand->siglock here. - */ - spin_lock(&p->sighand->siglock); - if (!(p->flags & PF_EXITING)) { - struct css_set *cset = task_css_set(p); - - if (!css_set_populated(cset)) - css_set_update_populated(cset, true); - list_add_tail(&p->cg_list, &cset->tasks); - get_css_set(cset); - cset->nr_tasks++; - } - spin_unlock(&p->sighand->siglock); - } while_each_thread(g, p); -out_unlock: - spin_unlock_irq(&css_set_lock); - read_unlock(&tasklist_lock); -} - static void init_cgroup_housekeeping(struct cgroup *cgrp) { struct cgroup_subsys *ss; @@ -1976,7 +1914,6 @@ void init_cgroup_root(struct cgroup_fs_context *ctx) atomic_set(&root->nr_cgrps, 1); cgrp->root = root; init_cgroup_housekeeping(cgrp); - idr_init(&root->cgroup_idr); root->flags = ctx->flags; if (ctx->release_agent) @@ -1997,12 +1934,6 @@ int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask) lockdep_assert_held(&cgroup_mutex); - ret = cgroup_idr_alloc(&root->cgroup_idr, root_cgrp, 1, 2, GFP_KERNEL); - if (ret < 0) - goto out; - root_cgrp->id = ret; - root_cgrp->ancestor_ids[0] = ret; - ret = percpu_ref_init(&root_cgrp->self.refcnt, css_release, 0, GFP_KERNEL); if (ret) @@ -2035,6 +1966,8 @@ int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask) goto exit_root_id; } root_cgrp->kn = root->kf_root->kn; + WARN_ON_ONCE(cgroup_ino(root_cgrp) != 1); + root_cgrp->ancestor_ids[0] = cgroup_id(root_cgrp); ret = css_populate_dir(&root_cgrp->self); if (ret) @@ -2188,13 +2121,6 @@ static int cgroup_init_fs_context(struct fs_context *fc) if (!ctx) return -ENOMEM; - /* - * The first time anyone tries to mount a cgroup, enable the list - * linking each css_set to its tasks and fix up all existing tasks. - */ - if (!use_task_css_set_links) - cgroup_enable_task_cg_lists(); - ctx->ns = current->nsproxy->cgroup_ns; get_cgroup_ns(ctx->ns); fc->fs_private = &ctx->kfc; @@ -2372,9 +2298,8 @@ static void cgroup_migrate_add_task(struct task_struct *task, if (task->flags & PF_EXITING) return; - /* leave @task alone if post_fork() hasn't linked it yet */ - if (list_empty(&task->cg_list)) - return; + /* cgroup_threadgroup_rwsem protects racing against forks */ + WARN_ON_ONCE(list_empty(&task->cg_list)); cset = task_css_set(task); if (!cset->mg_src_cgrp) @@ -2825,7 +2750,8 @@ int cgroup_attach_task(struct cgroup *dst_cgrp, struct task_struct *leader, return ret; } -struct task_struct *cgroup_procs_write_start(char *buf, bool threadgroup) +struct task_struct *cgroup_procs_write_start(char *buf, bool threadgroup, + bool *locked) __acquires(&cgroup_threadgroup_rwsem) { struct task_struct *tsk; @@ -2834,7 +2760,21 @@ struct task_struct *cgroup_procs_write_start(char *buf, bool threadgroup) if (kstrtoint(strstrip(buf), 0, &pid) || pid < 0) return ERR_PTR(-EINVAL); - percpu_down_write(&cgroup_threadgroup_rwsem); + /* + * If we migrate a single thread, we don't care about threadgroup + * stability. If the thread is `current`, it won't exit(2) under our + * hands or change PID through exec(2). We exclude + * cgroup_update_dfl_csses and other cgroup_{proc,thread}s_write + * callers by cgroup_mutex. + * Therefore, we can skip the global lock. + */ + lockdep_assert_held(&cgroup_mutex); + if (pid || threadgroup) { + percpu_down_write(&cgroup_threadgroup_rwsem); + *locked = true; + } else { + *locked = false; + } rcu_read_lock(); if (pid) { @@ -2865,13 +2805,16 @@ struct task_struct *cgroup_procs_write_start(char *buf, bool threadgroup) goto out_unlock_rcu; out_unlock_threadgroup: - percpu_up_write(&cgroup_threadgroup_rwsem); + if (*locked) { + percpu_up_write(&cgroup_threadgroup_rwsem); + *locked = false; + } out_unlock_rcu: rcu_read_unlock(); return tsk; } -void cgroup_procs_write_finish(struct task_struct *task) +void cgroup_procs_write_finish(struct task_struct *task, bool locked) __releases(&cgroup_threadgroup_rwsem) { struct cgroup_subsys *ss; @@ -2880,7 +2823,8 @@ void cgroup_procs_write_finish(struct task_struct *task) /* release reference from cgroup_procs_write_start() */ put_task_struct(task); - percpu_up_write(&cgroup_threadgroup_rwsem); + if (locked) + percpu_up_write(&cgroup_threadgroup_rwsem); for_each_subsys(ss, ssid) if (ss->post_attach) ss->post_attach(); @@ -3601,22 +3545,22 @@ static int cpu_stat_show(struct seq_file *seq, void *v) #ifdef CONFIG_PSI static int cgroup_io_pressure_show(struct seq_file *seq, void *v) { - struct cgroup *cgroup = seq_css(seq)->cgroup; - struct psi_group *psi = cgroup->id == 1 ? &psi_system : &cgroup->psi; + struct cgroup *cgrp = seq_css(seq)->cgroup; + struct psi_group *psi = cgroup_id(cgrp) == 1 ? &psi_system : &cgrp->psi; return psi_show(seq, psi, PSI_IO); } static int cgroup_memory_pressure_show(struct seq_file *seq, void *v) { - struct cgroup *cgroup = seq_css(seq)->cgroup; - struct psi_group *psi = cgroup->id == 1 ? &psi_system : &cgroup->psi; + struct cgroup *cgrp = seq_css(seq)->cgroup; + struct psi_group *psi = cgroup_id(cgrp) == 1 ? &psi_system : &cgrp->psi; return psi_show(seq, psi, PSI_MEM); } static int cgroup_cpu_pressure_show(struct seq_file *seq, void *v) { - struct cgroup *cgroup = seq_css(seq)->cgroup; - struct psi_group *psi = cgroup->id == 1 ? &psi_system : &cgroup->psi; + struct cgroup *cgrp = seq_css(seq)->cgroup; + struct psi_group *psi = cgroup_id(cgrp) == 1 ? &psi_system : &cgrp->psi; return psi_show(seq, psi, PSI_CPU); } @@ -4568,9 +4512,6 @@ repeat: void css_task_iter_start(struct cgroup_subsys_state *css, unsigned int flags, struct css_task_iter *it) { - /* no one should try to iterate before mounting cgroups */ - WARN_ON_ONCE(!use_task_css_set_links); - memset(it, 0, sizeof(*it)); spin_lock_irq(&css_set_lock); @@ -4755,12 +4696,13 @@ static ssize_t cgroup_procs_write(struct kernfs_open_file *of, struct cgroup *src_cgrp, *dst_cgrp; struct task_struct *task; ssize_t ret; + bool locked; dst_cgrp = cgroup_kn_lock_live(of->kn, false); if (!dst_cgrp) return -ENODEV; - task = cgroup_procs_write_start(buf, true); + task = cgroup_procs_write_start(buf, true, &locked); ret = PTR_ERR_OR_ZERO(task); if (ret) goto out_unlock; @@ -4778,7 +4720,7 @@ static ssize_t cgroup_procs_write(struct kernfs_open_file *of, ret = cgroup_attach_task(dst_cgrp, task, true); out_finish: - cgroup_procs_write_finish(task); + cgroup_procs_write_finish(task, locked); out_unlock: cgroup_kn_unlock(of->kn); @@ -4796,6 +4738,7 @@ static ssize_t cgroup_threads_write(struct kernfs_open_file *of, struct cgroup *src_cgrp, *dst_cgrp; struct task_struct *task; ssize_t ret; + bool locked; buf = strstrip(buf); @@ -4803,7 +4746,7 @@ static ssize_t cgroup_threads_write(struct kernfs_open_file *of, if (!dst_cgrp) return -ENODEV; - task = cgroup_procs_write_start(buf, false); + task = cgroup_procs_write_start(buf, false, &locked); ret = PTR_ERR_OR_ZERO(task); if (ret) goto out_unlock; @@ -4827,7 +4770,7 @@ static ssize_t cgroup_threads_write(struct kernfs_open_file *of, ret = cgroup_attach_task(dst_cgrp, task, false); out_finish: - cgroup_procs_write_finish(task); + cgroup_procs_write_finish(task, locked); out_unlock: cgroup_kn_unlock(of->kn); @@ -5037,9 +4980,6 @@ static void css_release_work_fn(struct work_struct *work) tcgrp->nr_dying_descendants--; spin_unlock_irq(&css_set_lock); - cgroup_idr_remove(&cgrp->root->cgroup_idr, cgrp->id); - cgrp->id = -1; - /* * There are two control paths which try to determine * cgroup from dentry without going through kernfs - @@ -5204,10 +5144,12 @@ err_free_css: * it isn't associated with its kernfs_node and doesn't have the control * mask applied. */ -static struct cgroup *cgroup_create(struct cgroup *parent) +static struct cgroup *cgroup_create(struct cgroup *parent, const char *name, + umode_t mode) { struct cgroup_root *root = parent->root; struct cgroup *cgrp, *tcgrp; + struct kernfs_node *kn; int level = parent->level + 1; int ret; @@ -5227,15 +5169,13 @@ static struct cgroup *cgroup_create(struct cgroup *parent) goto out_cancel_ref; } - /* - * Temporarily set the pointer to NULL, so idr_find() won't return - * a half-baked cgroup. - */ - cgrp->id = cgroup_idr_alloc(&root->cgroup_idr, NULL, 2, 0, GFP_KERNEL); - if (cgrp->id < 0) { - ret = -ENOMEM; + /* create the directory */ + kn = kernfs_create_dir(parent->kn, name, mode, cgrp); + if (IS_ERR(kn)) { + ret = PTR_ERR(kn); goto out_stat_exit; } + cgrp->kn = kn; init_cgroup_housekeeping(cgrp); @@ -5245,7 +5185,7 @@ static struct cgroup *cgroup_create(struct cgroup *parent) ret = psi_cgroup_alloc(cgrp); if (ret) - goto out_idr_free; + goto out_kernfs_remove; ret = cgroup_bpf_inherit(cgrp); if (ret) @@ -5269,7 +5209,7 @@ static struct cgroup *cgroup_create(struct cgroup *parent) spin_lock_irq(&css_set_lock); for (tcgrp = cgrp; tcgrp; tcgrp = cgroup_parent(tcgrp)) { - cgrp->ancestor_ids[tcgrp->level] = tcgrp->id; + cgrp->ancestor_ids[tcgrp->level] = cgroup_id(tcgrp); if (tcgrp != cgrp) { tcgrp->nr_descendants++; @@ -5299,12 +5239,6 @@ static struct cgroup *cgroup_create(struct cgroup *parent) cgroup_get_live(parent); /* - * @cgrp is now fully operational. If something fails after this - * point, it'll be released via the normal destruction path. - */ - cgroup_idr_replace(&root->cgroup_idr, cgrp, cgrp->id); - - /* * On the default hierarchy, a child doesn't automatically inherit * subtree_control from the parent. Each is configured manually. */ @@ -5317,8 +5251,8 @@ static struct cgroup *cgroup_create(struct cgroup *parent) out_psi_free: psi_cgroup_free(cgrp); -out_idr_free: - cgroup_idr_remove(&root->cgroup_idr, cgrp->id); +out_kernfs_remove: + kernfs_remove(cgrp->kn); out_stat_exit: if (cgroup_on_dfl(parent)) cgroup_rstat_exit(cgrp); @@ -5355,7 +5289,6 @@ fail: int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, umode_t mode) { struct cgroup *parent, *cgrp; - struct kernfs_node *kn; int ret; /* do not accept '\n' to prevent making /proc/<pid>/cgroup unparsable */ @@ -5371,27 +5304,19 @@ int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, umode_t mode) goto out_unlock; } - cgrp = cgroup_create(parent); + cgrp = cgroup_create(parent, name, mode); if (IS_ERR(cgrp)) { ret = PTR_ERR(cgrp); goto out_unlock; } - /* create the directory */ - kn = kernfs_create_dir(parent->kn, name, mode, cgrp); - if (IS_ERR(kn)) { - ret = PTR_ERR(kn); - goto out_destroy; - } - cgrp->kn = kn; - /* * This extra ref will be put in cgroup_free_fn() and guarantees * that @cgrp->kn is always accessible. */ - kernfs_get(kn); + kernfs_get(cgrp->kn); - ret = cgroup_kn_set_ugid(kn); + ret = cgroup_kn_set_ugid(cgrp->kn); if (ret) goto out_destroy; @@ -5406,7 +5331,7 @@ int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, umode_t mode) TRACE_CGROUP_PATH(mkdir, cgrp); /* let's create and online css's */ - kernfs_activate(kn); + kernfs_activate(cgrp->kn); ret = 0; goto out_unlock; @@ -5836,12 +5761,11 @@ static int __init cgroup_wq_init(void) } core_initcall(cgroup_wq_init); -void cgroup_path_from_kernfs_id(const union kernfs_node_id *id, - char *buf, size_t buflen) +void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen) { struct kernfs_node *kn; - kn = kernfs_get_node_by_id(cgrp_dfl_root.kf_root, id); + kn = kernfs_find_and_get_node_by_id(cgrp_dfl_root.kf_root, id); if (!kn) return; kernfs_path(kn, buf, buflen); @@ -6002,62 +5926,38 @@ void cgroup_cancel_fork(struct task_struct *child) void cgroup_post_fork(struct task_struct *child) { struct cgroup_subsys *ss; + struct css_set *cset; int i; + spin_lock_irq(&css_set_lock); + + WARN_ON_ONCE(!list_empty(&child->cg_list)); + cset = task_css_set(current); /* current is @child's parent */ + get_css_set(cset); + cset->nr_tasks++; + css_set_move_task(child, NULL, cset, false); + /* - * This may race against cgroup_enable_task_cg_lists(). As that - * function sets use_task_css_set_links before grabbing - * tasklist_lock and we just went through tasklist_lock to add - * @child, it's guaranteed that either we see the set - * use_task_css_set_links or cgroup_enable_task_cg_lists() sees - * @child during its iteration. - * - * If we won the race, @child is associated with %current's - * css_set. Grabbing css_set_lock guarantees both that the - * association is stable, and, on completion of the parent's - * migration, @child is visible in the source of migration or - * already in the destination cgroup. This guarantee is necessary - * when implementing operations which need to migrate all tasks of - * a cgroup to another. - * - * Note that if we lose to cgroup_enable_task_cg_lists(), @child - * will remain in init_css_set. This is safe because all tasks are - * in the init_css_set before cg_links is enabled and there's no - * operation which transfers all tasks out of init_css_set. + * If the cgroup has to be frozen, the new task has too. Let's set + * the JOBCTL_TRAP_FREEZE jobctl bit to get the task into the + * frozen state. */ - if (use_task_css_set_links) { - struct css_set *cset; - - spin_lock_irq(&css_set_lock); - cset = task_css_set(current); - if (list_empty(&child->cg_list)) { - get_css_set(cset); - cset->nr_tasks++; - css_set_move_task(child, NULL, cset, false); - } + if (unlikely(cgroup_task_freeze(child))) { + spin_lock(&child->sighand->siglock); + WARN_ON_ONCE(child->frozen); + child->jobctl |= JOBCTL_TRAP_FREEZE; + spin_unlock(&child->sighand->siglock); /* - * If the cgroup has to be frozen, the new task has too. - * Let's set the JOBCTL_TRAP_FREEZE jobctl bit to get - * the task into the frozen state. + * Calling cgroup_update_frozen() isn't required here, + * because it will be called anyway a bit later from + * do_freezer_trap(). So we avoid cgroup's transient switch + * from the frozen state and back. */ - if (unlikely(cgroup_task_freeze(child))) { - spin_lock(&child->sighand->siglock); - WARN_ON_ONCE(child->frozen); - child->jobctl |= JOBCTL_TRAP_FREEZE; - spin_unlock(&child->sighand->siglock); - - /* - * Calling cgroup_update_frozen() isn't required here, - * because it will be called anyway a bit later - * from do_freezer_trap(). So we avoid cgroup's - * transient switch from the frozen state and back. - */ - } - - spin_unlock_irq(&css_set_lock); } + spin_unlock_irq(&css_set_lock); + /* * Call ss->fork(). This must happen after @child is linked on * css_set; otherwise, @child might change state between ->fork() @@ -6072,20 +5972,8 @@ void cgroup_post_fork(struct task_struct *child) * cgroup_exit - detach cgroup from exiting task * @tsk: pointer to task_struct of exiting process * - * Description: Detach cgroup from @tsk and release it. + * Description: Detach cgroup from @tsk. * - * Note that cgroups marked notify_on_release force every task in - * them to take the global cgroup_mutex mutex when exiting. - * This could impact scaling on very large systems. Be reluctant to - * use notify_on_release cgroups where very high task exit scaling - * is required on large systems. - * - * We set the exiting tasks cgroup to the root cgroup (top_cgroup). We - * call cgroup_exit() while the task is still competent to handle - * notify_on_release(), then leave the task attached to the root cgroup in - * each hierarchy for the remainder of its exit. No need to bother with - * init_css_set refcnting. init_css_set never goes away and we can't race - * with migration path - PF_EXITING is visible to migration path. */ void cgroup_exit(struct task_struct *tsk) { @@ -6093,26 +5981,19 @@ void cgroup_exit(struct task_struct *tsk) struct css_set *cset; int i; - /* - * Unlink from @tsk from its css_set. As migration path can't race - * with us, we can check css_set and cg_list without synchronization. - */ - cset = task_css_set(tsk); + spin_lock_irq(&css_set_lock); - if (!list_empty(&tsk->cg_list)) { - spin_lock_irq(&css_set_lock); - css_set_move_task(tsk, cset, NULL, false); - list_add_tail(&tsk->cg_list, &cset->dying_tasks); - cset->nr_tasks--; + WARN_ON_ONCE(list_empty(&tsk->cg_list)); + cset = task_css_set(tsk); + css_set_move_task(tsk, cset, NULL, false); + list_add_tail(&tsk->cg_list, &cset->dying_tasks); + cset->nr_tasks--; - WARN_ON_ONCE(cgroup_task_frozen(tsk)); - if (unlikely(cgroup_task_freeze(tsk))) - cgroup_update_frozen(task_dfl_cgroup(tsk)); + WARN_ON_ONCE(cgroup_task_frozen(tsk)); + if (unlikely(cgroup_task_freeze(tsk))) + cgroup_update_frozen(task_dfl_cgroup(tsk)); - spin_unlock_irq(&css_set_lock); - } else { - get_css_set(cset); - } + spin_unlock_irq(&css_set_lock); /* see cgroup_post_fork() for details */ do_each_subsys_mask(ss, i, have_exit_callback) { @@ -6129,12 +6010,10 @@ void cgroup_release(struct task_struct *task) ss->release(task); } while_each_subsys_mask(); - if (use_task_css_set_links) { - spin_lock_irq(&css_set_lock); - css_set_skip_task_iters(task_css_set(task), task); - list_del_init(&task->cg_list); - spin_unlock_irq(&css_set_lock); - } + spin_lock_irq(&css_set_lock); + css_set_skip_task_iters(task_css_set(task), task); + list_del_init(&task->cg_list); + spin_unlock_irq(&css_set_lock); } void cgroup_free(struct task_struct *task) diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index c87ee6412b36..58f5073acff7 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -929,8 +929,6 @@ static void rebuild_root_domains(void) lockdep_assert_cpus_held(); lockdep_assert_held(&sched_domains_mutex); - cgroup_enable_task_cg_lists(); - rcu_read_lock(); /* diff --git a/kernel/cgroup/freezer.c b/kernel/cgroup/freezer.c index 8cf010680678..3984dd6b8ddb 100644 --- a/kernel/cgroup/freezer.c +++ b/kernel/cgroup/freezer.c @@ -231,6 +231,15 @@ void cgroup_freezer_migrate_task(struct task_struct *task, return; /* + * It's not necessary to do changes if both of the src and dst cgroups + * are not freezing and task is not frozen. + */ + if (!test_bit(CGRP_FREEZE, &src->flags) && + !test_bit(CGRP_FREEZE, &dst->flags) && + !task->frozen) + return; + + /* * Adjust counters of freezing and frozen tasks. * Note, that if the task is frozen, but the destination cgroup is not * frozen, we bump both counters to keep them balanced. diff --git a/kernel/cgroup/pids.c b/kernel/cgroup/pids.c index 8e513a573fe9..138059eb730d 100644 --- a/kernel/cgroup/pids.c +++ b/kernel/cgroup/pids.c @@ -45,7 +45,7 @@ struct pids_cgroup { * %PIDS_MAX = (%PID_MAX_LIMIT + 1). */ atomic64_t counter; - int64_t limit; + atomic64_t limit; /* Handle for "pids.events" */ struct cgroup_file events_file; @@ -73,8 +73,8 @@ pids_css_alloc(struct cgroup_subsys_state *parent) if (!pids) return ERR_PTR(-ENOMEM); - pids->limit = PIDS_MAX; atomic64_set(&pids->counter, 0); + atomic64_set(&pids->limit, PIDS_MAX); atomic64_set(&pids->events_limit, 0); return &pids->css; } @@ -146,13 +146,14 @@ static int pids_try_charge(struct pids_cgroup *pids, int num) for (p = pids; parent_pids(p); p = parent_pids(p)) { int64_t new = atomic64_add_return(num, &p->counter); + int64_t limit = atomic64_read(&p->limit); /* * Since new is capped to the maximum number of pid_t, if * p->limit is %PIDS_MAX then we know that this test will never * fail. */ - if (new > p->limit) + if (new > limit) goto revert; } @@ -277,7 +278,7 @@ set_limit: * Limit updates don't need to be mutex'd, since it isn't * critical that any racing fork()s follow the new limit. */ - pids->limit = limit; + atomic64_set(&pids->limit, limit); return nbytes; } @@ -285,7 +286,7 @@ static int pids_max_show(struct seq_file *sf, void *v) { struct cgroup_subsys_state *css = seq_css(sf); struct pids_cgroup *pids = css_pids(css); - int64_t limit = pids->limit; + int64_t limit = atomic64_read(&pids->limit); if (limit >= PIDS_MAX) seq_printf(sf, "%s\n", PIDS_MAX_STR); diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c index ca19b4c8acf5..b48b22d4deb6 100644 --- a/kernel/cgroup/rstat.c +++ b/kernel/cgroup/rstat.c @@ -304,44 +304,48 @@ void __init cgroup_rstat_boot(void) * Functions for cgroup basic resource statistics implemented on top of * rstat. */ -static void cgroup_base_stat_accumulate(struct cgroup_base_stat *dst_bstat, - struct cgroup_base_stat *src_bstat) +static void cgroup_base_stat_add(struct cgroup_base_stat *dst_bstat, + struct cgroup_base_stat *src_bstat) { dst_bstat->cputime.utime += src_bstat->cputime.utime; dst_bstat->cputime.stime += src_bstat->cputime.stime; dst_bstat->cputime.sum_exec_runtime += src_bstat->cputime.sum_exec_runtime; } +static void cgroup_base_stat_sub(struct cgroup_base_stat *dst_bstat, + struct cgroup_base_stat *src_bstat) +{ + dst_bstat->cputime.utime -= src_bstat->cputime.utime; + dst_bstat->cputime.stime -= src_bstat->cputime.stime; + dst_bstat->cputime.sum_exec_runtime -= src_bstat->cputime.sum_exec_runtime; +} + static void cgroup_base_stat_flush(struct cgroup *cgrp, int cpu) { struct cgroup *parent = cgroup_parent(cgrp); struct cgroup_rstat_cpu *rstatc = cgroup_rstat_cpu(cgrp, cpu); - struct task_cputime *last_cputime = &rstatc->last_bstat.cputime; - struct task_cputime cputime; - struct cgroup_base_stat delta; + struct cgroup_base_stat cur, delta; unsigned seq; /* fetch the current per-cpu values */ do { seq = __u64_stats_fetch_begin(&rstatc->bsync); - cputime = rstatc->bstat.cputime; + cur.cputime = rstatc->bstat.cputime; } while (__u64_stats_fetch_retry(&rstatc->bsync, seq)); - /* calculate the delta to propgate */ - delta.cputime.utime = cputime.utime - last_cputime->utime; - delta.cputime.stime = cputime.stime - last_cputime->stime; - delta.cputime.sum_exec_runtime = cputime.sum_exec_runtime - - last_cputime->sum_exec_runtime; - *last_cputime = cputime; - - /* transfer the pending stat into delta */ - cgroup_base_stat_accumulate(&delta, &cgrp->pending_bstat); - memset(&cgrp->pending_bstat, 0, sizeof(cgrp->pending_bstat)); - - /* propagate delta into the global stat and the parent's pending */ - cgroup_base_stat_accumulate(&cgrp->bstat, &delta); - if (parent) - cgroup_base_stat_accumulate(&parent->pending_bstat, &delta); + /* propagate percpu delta to global */ + delta = cur; + cgroup_base_stat_sub(&delta, &rstatc->last_bstat); + cgroup_base_stat_add(&cgrp->bstat, &delta); + cgroup_base_stat_add(&rstatc->last_bstat, &delta); + + /* propagate global delta to parent */ + if (parent) { + delta = cgrp->bstat; + cgroup_base_stat_sub(&delta, &cgrp->last_bstat); + cgroup_base_stat_add(&parent->bstat, &delta); + cgroup_base_stat_add(&cgrp->last_bstat, &delta); + } } static struct cgroup_rstat_cpu * diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index 2d6e93ab0478..475e29498bca 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -64,8 +64,7 @@ static void blk_unregister_tracepoints(void); * Send out a notify message. */ static void trace_note(struct blk_trace *bt, pid_t pid, int action, - const void *data, size_t len, - union kernfs_node_id *cgid) + const void *data, size_t len, u64 cgid) { struct blk_io_trace *t; struct ring_buffer_event *event = NULL; @@ -73,7 +72,7 @@ static void trace_note(struct blk_trace *bt, pid_t pid, int action, int pc = 0; int cpu = smp_processor_id(); bool blk_tracer = blk_tracer_enabled; - ssize_t cgid_len = cgid ? sizeof(*cgid) : 0; + ssize_t cgid_len = cgid ? sizeof(cgid) : 0; if (blk_tracer) { buffer = blk_tr->trace_buffer.buffer; @@ -100,8 +99,8 @@ record_it: t->pid = pid; t->cpu = cpu; t->pdu_len = len + cgid_len; - if (cgid) - memcpy((void *)t + sizeof(*t), cgid, cgid_len); + if (cgid_len) + memcpy((void *)t + sizeof(*t), &cgid, cgid_len); memcpy((void *) t + sizeof(*t) + cgid_len, data, len); if (blk_tracer) @@ -122,7 +121,7 @@ static void trace_note_tsk(struct task_struct *tsk) spin_lock_irqsave(&running_trace_lock, flags); list_for_each_entry(bt, &running_trace_list, running_list) { trace_note(bt, tsk->pid, BLK_TN_PROCESS, tsk->comm, - sizeof(tsk->comm), NULL); + sizeof(tsk->comm), 0); } spin_unlock_irqrestore(&running_trace_lock, flags); } @@ -139,7 +138,7 @@ static void trace_note_time(struct blk_trace *bt) words[1] = now.tv_nsec; local_irq_save(flags); - trace_note(bt, 0, BLK_TN_TIMESTAMP, words, sizeof(words), NULL); + trace_note(bt, 0, BLK_TN_TIMESTAMP, words, sizeof(words), 0); local_irq_restore(flags); } @@ -172,9 +171,9 @@ void __trace_note_message(struct blk_trace *bt, struct blkcg *blkcg, blkcg = NULL; #ifdef CONFIG_BLK_CGROUP trace_note(bt, 0, BLK_TN_MESSAGE, buf, n, - blkcg ? cgroup_get_kernfs_id(blkcg->css.cgroup) : NULL); + blkcg ? cgroup_id(blkcg->css.cgroup) : 1); #else - trace_note(bt, 0, BLK_TN_MESSAGE, buf, n, NULL); + trace_note(bt, 0, BLK_TN_MESSAGE, buf, n, 0); #endif local_irq_restore(flags); } @@ -212,7 +211,7 @@ static const u32 ddir_act[2] = { BLK_TC_ACT(BLK_TC_READ), */ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes, int op, int op_flags, u32 what, int error, int pdu_len, - void *pdu_data, union kernfs_node_id *cgid) + void *pdu_data, u64 cgid) { struct task_struct *tsk = current; struct ring_buffer_event *event = NULL; @@ -223,7 +222,7 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes, pid_t pid; int cpu, pc = 0; bool blk_tracer = blk_tracer_enabled; - ssize_t cgid_len = cgid ? sizeof(*cgid) : 0; + ssize_t cgid_len = cgid ? sizeof(cgid) : 0; if (unlikely(bt->trace_state != Blktrace_running && !blk_tracer)) return; @@ -294,7 +293,7 @@ record_it: t->pdu_len = pdu_len + cgid_len; if (cgid_len) - memcpy((void *)t + sizeof(*t), cgid, cgid_len); + memcpy((void *)t + sizeof(*t), &cgid, cgid_len); if (pdu_len) memcpy((void *)t + sizeof(*t) + cgid_len, pdu_data, pdu_len); @@ -751,31 +750,29 @@ void blk_trace_shutdown(struct request_queue *q) } #ifdef CONFIG_BLK_CGROUP -static union kernfs_node_id * -blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio) +static u64 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio) { struct blk_trace *bt = q->blk_trace; if (!bt || !(blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP)) - return NULL; + return 0; if (!bio->bi_blkg) - return NULL; - return cgroup_get_kernfs_id(bio_blkcg(bio)->css.cgroup); + return 0; + return cgroup_id(bio_blkcg(bio)->css.cgroup); } #else -static union kernfs_node_id * -blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio) +u64 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio) { - return NULL; + return 0; } #endif -static union kernfs_node_id * +static u64 blk_trace_request_get_cgid(struct request_queue *q, struct request *rq) { if (!rq->bio) - return NULL; + return 0; /* Use the first bio */ return blk_trace_bio_get_cgid(q, rq->bio); } @@ -797,8 +794,7 @@ blk_trace_request_get_cgid(struct request_queue *q, struct request *rq) * **/ static void blk_add_trace_rq(struct request *rq, int error, - unsigned int nr_bytes, u32 what, - union kernfs_node_id *cgid) + unsigned int nr_bytes, u32 what, u64 cgid) { struct blk_trace *bt = rq->q->blk_trace; @@ -913,7 +909,7 @@ static void blk_add_trace_getrq(void *ignore, if (bt) __blk_add_trace(bt, 0, 0, rw, 0, BLK_TA_GETRQ, 0, 0, - NULL, NULL); + NULL, 0); } } @@ -929,7 +925,7 @@ static void blk_add_trace_sleeprq(void *ignore, if (bt) __blk_add_trace(bt, 0, 0, rw, 0, BLK_TA_SLEEPRQ, - 0, 0, NULL, NULL); + 0, 0, NULL, 0); } } @@ -938,7 +934,7 @@ static void blk_add_trace_plug(void *ignore, struct request_queue *q) struct blk_trace *bt = q->blk_trace; if (bt) - __blk_add_trace(bt, 0, 0, 0, 0, BLK_TA_PLUG, 0, 0, NULL, NULL); + __blk_add_trace(bt, 0, 0, 0, 0, BLK_TA_PLUG, 0, 0, NULL, 0); } static void blk_add_trace_unplug(void *ignore, struct request_queue *q, @@ -955,7 +951,7 @@ static void blk_add_trace_unplug(void *ignore, struct request_queue *q, else what = BLK_TA_UNPLUG_TIMER; - __blk_add_trace(bt, 0, 0, 0, 0, what, 0, sizeof(rpdu), &rpdu, NULL); + __blk_add_trace(bt, 0, 0, 0, 0, what, 0, sizeof(rpdu), &rpdu, 0); } } @@ -1172,19 +1168,17 @@ const struct blk_io_trace *te_blk_io_trace(const struct trace_entry *ent) static inline const void *pdu_start(const struct trace_entry *ent, bool has_cg) { - return (void *)(te_blk_io_trace(ent) + 1) + - (has_cg ? sizeof(union kernfs_node_id) : 0); + return (void *)(te_blk_io_trace(ent) + 1) + (has_cg ? sizeof(u64) : 0); } -static inline const void *cgid_start(const struct trace_entry *ent) +static inline u64 t_cgid(const struct trace_entry *ent) { - return (void *)(te_blk_io_trace(ent) + 1); + return *(u64 *)(te_blk_io_trace(ent) + 1); } static inline int pdu_real_len(const struct trace_entry *ent, bool has_cg) { - return te_blk_io_trace(ent)->pdu_len - - (has_cg ? sizeof(union kernfs_node_id) : 0); + return te_blk_io_trace(ent)->pdu_len - (has_cg ? sizeof(u64) : 0); } static inline u32 t_action(const struct trace_entry *ent) @@ -1257,7 +1251,7 @@ static void blk_log_action(struct trace_iterator *iter, const char *act, fill_rwbs(rwbs, t); if (has_cg) { - const union kernfs_node_id *id = cgid_start(iter->ent); + u64 id = t_cgid(iter->ent); if (blk_tracer_flags.val & TRACE_BLK_OPT_CGNAME) { char blkcg_name_buf[NAME_MAX + 1] = "<...>"; @@ -1267,11 +1261,25 @@ static void blk_log_action(struct trace_iterator *iter, const char *act, trace_seq_printf(&iter->seq, "%3d,%-3d %s %2s %3s ", MAJOR(t->device), MINOR(t->device), blkcg_name_buf, act, rwbs); - } else + } else { + /* + * The cgid portion used to be "INO,GEN". Userland + * builds a FILEID_INO32_GEN fid out of them and + * opens the cgroup using open_by_handle_at(2). + * While 32bit ino setups are still the same, 64bit + * ones now use the 64bit ino as the whole ID and + * no longer use generation. + * + * Regarldess of the content, always output + * "LOW32,HIGH32" so that FILEID_INO32_GEN fid can + * be mapped back to @id on both 64 and 32bit ino + * setups. See __kernfs_fh_to_dentry(). + */ trace_seq_printf(&iter->seq, - "%3d,%-3d %x,%-x %2s %3s ", + "%3d,%-3d %llx,%-llx %2s %3s ", MAJOR(t->device), MINOR(t->device), - id->ino, id->generation, act, rwbs); + id & U32_MAX, id >> 32, act, rwbs); + } } else trace_seq_printf(&iter->seq, "%3d,%-3d %2s %3s ", MAJOR(t->device), MINOR(t->device), act, rwbs); |