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,
}
/**
- * 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.
{
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)
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);
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))
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
.seq_show = cgroup_freeze_show,
.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,
},
{
.name = "memory.pressure",
+ .flags = CFTYPE_PRESSURE,
.seq_show = cgroup_memory_pressure_show,
.write = cgroup_memory_pressure_write,
.poll = cgroup_pressure_poll,
},
{
.name = "cpu.pressure",
+ .flags = CFTYPE_PRESSURE,
.seq_show = cgroup_cpu_pressure_show,
.write = cgroup_cpu_pressure_write,
.poll = cgroup_pressure_poll,
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;
/* 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);
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);
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);
}
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);
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;
}
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);
git.samba.org / sfrench / cifs-2.6.git / blobdiff