diff options
Diffstat (limited to 'kernel/cgroup/cgroup.c')
| -rw-r--r-- | kernel/cgroup/cgroup.c | 180 |
1 files changed, 164 insertions, 16 deletions
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 9cc8c3a686b1..ea5b0f01d2b3 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -209,6 +209,22 @@ struct cgroup_namespace init_cgroup_ns = { static struct file_system_type cgroup2_fs_type; static struct cftype cgroup_base_files[]; +/* cgroup optional features */ +enum cgroup_opt_features { +#ifdef CONFIG_PSI + OPT_FEATURE_PRESSURE, +#endif + OPT_FEATURE_COUNT +}; + +static const char *cgroup_opt_feature_names[OPT_FEATURE_COUNT] = { +#ifdef CONFIG_PSI + "pressure", +#endif +}; + +static u16 cgroup_feature_disable_mask __read_mostly; + static int cgroup_apply_control(struct cgroup *cgrp); static void cgroup_finalize_control(struct cgroup *cgrp, int ret); static void css_task_iter_skip(struct css_task_iter *it, @@ -2390,7 +2406,7 @@ struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset, } /** - * cgroup_taskset_migrate - migrate a taskset + * cgroup_migrate_execute - migrate a taskset * @mgctx: migration context * * Migrate tasks in @mgctx as setup by migration preparation functions. @@ -3632,6 +3648,18 @@ static void cgroup_pressure_release(struct kernfs_open_file *of) { psi_trigger_replace(&of->priv, NULL); } + +bool cgroup_psi_enabled(void) +{ + return (cgroup_feature_disable_mask & (1 << OPT_FEATURE_PRESSURE)) == 0; +} + +#else /* CONFIG_PSI */ +bool cgroup_psi_enabled(void) +{ + return false; +} + #endif /* CONFIG_PSI */ static int cgroup_freeze_show(struct seq_file *seq, void *v) @@ -3668,6 +3696,80 @@ static ssize_t cgroup_freeze_write(struct kernfs_open_file *of, return nbytes; } +static void __cgroup_kill(struct cgroup *cgrp) +{ + struct css_task_iter it; + struct task_struct *task; + + lockdep_assert_held(&cgroup_mutex); + + spin_lock_irq(&css_set_lock); + set_bit(CGRP_KILL, &cgrp->flags); + spin_unlock_irq(&css_set_lock); + + css_task_iter_start(&cgrp->self, CSS_TASK_ITER_PROCS | CSS_TASK_ITER_THREADED, &it); + while ((task = css_task_iter_next(&it))) { + /* Ignore kernel threads here. */ + if (task->flags & PF_KTHREAD) + continue; + + /* Skip tasks that are already dying. */ + if (__fatal_signal_pending(task)) + continue; + + send_sig(SIGKILL, task, 0); + } + css_task_iter_end(&it); + + spin_lock_irq(&css_set_lock); + clear_bit(CGRP_KILL, &cgrp->flags); + spin_unlock_irq(&css_set_lock); +} + +static void cgroup_kill(struct cgroup *cgrp) +{ + struct cgroup_subsys_state *css; + struct cgroup *dsct; + + lockdep_assert_held(&cgroup_mutex); + + cgroup_for_each_live_descendant_pre(dsct, css, cgrp) + __cgroup_kill(dsct); +} + +static ssize_t cgroup_kill_write(struct kernfs_open_file *of, char *buf, + size_t nbytes, loff_t off) +{ + ssize_t ret = 0; + int kill; + struct cgroup *cgrp; + + ret = kstrtoint(strstrip(buf), 0, &kill); + if (ret) + return ret; + + if (kill != 1) + return -ERANGE; + + cgrp = cgroup_kn_lock_live(of->kn, false); + if (!cgrp) + return -ENOENT; + + /* + * Killing is a process directed operation, i.e. the whole thread-group + * is taken down so act like we do for cgroup.procs and only make this + * writable in non-threaded cgroups. + */ + if (cgroup_is_threaded(cgrp)) + ret = -EOPNOTSUPP; + else + cgroup_kill(cgrp); + + cgroup_kn_unlock(of->kn); + + return ret ?: nbytes; +} + static int cgroup_file_open(struct kernfs_open_file *of) { struct cftype *cft = of_cft(of); @@ -3882,6 +3984,8 @@ static int cgroup_addrm_files(struct cgroup_subsys_state *css, restart: for (cft = cfts; cft != cft_end && cft->name[0] != '\0'; cft++) { /* does cft->flags tell us to skip this file on @cgrp? */ + if ((cft->flags & CFTYPE_PRESSURE) && !cgroup_psi_enabled()) + continue; if ((cft->flags & __CFTYPE_ONLY_ON_DFL) && !cgroup_on_dfl(cgrp)) continue; if ((cft->flags & __CFTYPE_NOT_ON_DFL) && cgroup_on_dfl(cgrp)) @@ -3959,6 +4063,9 @@ static int cgroup_init_cftypes(struct cgroup_subsys *ss, struct cftype *cfts) WARN_ON(cft->ss || cft->kf_ops); + if ((cft->flags & CFTYPE_PRESSURE) && !cgroup_psi_enabled()) + continue; + if (cft->seq_start) kf_ops = &cgroup_kf_ops; else @@ -4861,12 +4968,18 @@ static struct cftype cgroup_base_files[] = { .write = cgroup_freeze_write, }, { + .name = "cgroup.kill", + .flags = CFTYPE_NOT_ON_ROOT, + .write = cgroup_kill_write, + }, + { .name = "cpu.stat", .seq_show = cpu_stat_show, }, #ifdef CONFIG_PSI { .name = "io.pressure", + .flags = CFTYPE_PRESSURE, .seq_show = cgroup_io_pressure_show, .write = cgroup_io_pressure_write, .poll = cgroup_pressure_poll, @@ -4874,6 +4987,7 @@ static struct cftype cgroup_base_files[] = { }, { .name = "memory.pressure", + .flags = CFTYPE_PRESSURE, .seq_show = cgroup_memory_pressure_show, .write = cgroup_memory_pressure_write, .poll = cgroup_pressure_poll, @@ -4881,6 +4995,7 @@ static struct cftype cgroup_base_files[] = { }, { .name = "cpu.pressure", + .flags = CFTYPE_PRESSURE, .seq_show = cgroup_cpu_pressure_show, .write = cgroup_cpu_pressure_write, .poll = cgroup_pressure_poll, @@ -6080,6 +6195,8 @@ void cgroup_post_fork(struct task_struct *child, struct kernel_clone_args *kargs) __releases(&cgroup_threadgroup_rwsem) __releases(&cgroup_mutex) { + unsigned long cgrp_flags = 0; + bool kill = false; struct cgroup_subsys *ss; struct css_set *cset; int i; @@ -6091,6 +6208,11 @@ void cgroup_post_fork(struct task_struct *child, /* init tasks are special, only link regular threads */ if (likely(child->pid)) { + if (kargs->cgrp) + cgrp_flags = kargs->cgrp->flags; + else + cgrp_flags = cset->dfl_cgrp->flags; + WARN_ON_ONCE(!list_empty(&child->cg_list)); cset->nr_tasks++; css_set_move_task(child, NULL, cset, false); @@ -6099,23 +6221,32 @@ void cgroup_post_fork(struct task_struct *child, cset = NULL; } - /* - * 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 (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 (!(child->flags & PF_KTHREAD)) { + if (unlikely(test_bit(CGRP_FREEZE, &cgrp_flags))) { + /* + * 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. + */ + 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. + */ + } /* - * 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 the cgroup is to be killed notice it now and take the + * child down right after we finished preparing it for + * userspace. */ + kill = test_bit(CGRP_KILL, &cgrp_flags); } spin_unlock_irq(&css_set_lock); @@ -6138,6 +6269,10 @@ void cgroup_post_fork(struct task_struct *child, put_css_set(rcset); } + /* Cgroup has to be killed so take down child immediately. */ + if (unlikely(kill)) + do_send_sig_info(SIGKILL, SEND_SIG_NOINFO, child, PIDTYPE_TGID); + cgroup_css_set_put_fork(kargs); } @@ -6163,7 +6298,8 @@ void cgroup_exit(struct task_struct *tsk) cset->nr_tasks--; WARN_ON_ONCE(cgroup_task_frozen(tsk)); - if (unlikely(cgroup_task_freeze(tsk))) + if (unlikely(!(tsk->flags & PF_KTHREAD) && + test_bit(CGRP_FREEZE, &task_dfl_cgroup(tsk)->flags))) cgroup_update_frozen(task_dfl_cgroup(tsk)); spin_unlock_irq(&css_set_lock); @@ -6214,6 +6350,15 @@ static int __init cgroup_disable(char *str) pr_info("Disabling %s control group subsystem\n", ss->name); } + + for (i = 0; i < OPT_FEATURE_COUNT; i++) { + if (strcmp(token, cgroup_opt_feature_names[i])) + continue; + cgroup_feature_disable_mask |= 1 << i; + pr_info("Disabling %s control group feature\n", + cgroup_opt_feature_names[i]); + break; + } } return 1; } @@ -6512,6 +6657,9 @@ static ssize_t show_delegatable_files(struct cftype *files, char *buf, if (!(cft->flags & CFTYPE_NS_DELEGATABLE)) continue; + if ((cft->flags & CFTYPE_PRESSURE) && !cgroup_psi_enabled()) + continue; + if (prefix) ret += snprintf(buf + ret, size - ret, "%s.", prefix); |