static DEFINE_MUTEX(cpuset_mutex);
static DEFINE_SPINLOCK(callback_lock);
+static struct workqueue_struct *cpuset_migrate_mm_wq;
+
/*
* CPU / memory hotplug is handled asynchronously.
*/
/* On legacy hiearchy, we must be a subset of our parent cpuset. */
ret = -EACCES;
- if (!cgroup_on_dfl(cur->css.cgroup) && !is_cpuset_subset(trial, par))
+ if (!cgroup_subsys_on_dfl(cpuset_cgrp_subsys) &&
+ !is_cpuset_subset(trial, par))
goto out;
/*
* be changed to have empty cpus_allowed or mems_allowed.
*/
ret = -ENOSPC;
- if ((cgroup_has_tasks(cur->css.cgroup) || cur->attach_in_progress)) {
+ if ((cgroup_is_populated(cur->css.cgroup) || cur->attach_in_progress)) {
if (!cpumask_empty(cur->cpus_allowed) &&
cpumask_empty(trial->cpus_allowed))
goto out;
* If it becomes empty, inherit the effective mask of the
* parent, which is guaranteed to have some CPUs.
*/
- if (cgroup_on_dfl(cp->css.cgroup) && cpumask_empty(new_cpus))
+ if (cgroup_subsys_on_dfl(cpuset_cgrp_subsys) &&
+ cpumask_empty(new_cpus))
cpumask_copy(new_cpus, parent->effective_cpus);
/* Skip the whole subtree if the cpumask remains the same. */
cpumask_copy(cp->effective_cpus, new_cpus);
spin_unlock_irq(&callback_lock);
- WARN_ON(!cgroup_on_dfl(cp->css.cgroup) &&
+ WARN_ON(!cgroup_subsys_on_dfl(cpuset_cgrp_subsys) &&
!cpumask_equal(cp->cpus_allowed, cp->effective_cpus));
update_tasks_cpumask(cp);
}
/*
- * cpuset_migrate_mm
- *
- * Migrate memory region from one set of nodes to another.
- *
- * Temporarilly set tasks mems_allowed to target nodes of migration,
- * so that the migration code can allocate pages on these nodes.
- *
- * While the mm_struct we are migrating is typically from some
- * other task, the task_struct mems_allowed that we are hacking
- * is for our current task, which must allocate new pages for that
- * migrating memory region.
+ * Migrate memory region from one set of nodes to another. This is
+ * performed asynchronously as it can be called from process migration path
+ * holding locks involved in process management. All mm migrations are
+ * performed in the queued order and can be waited for by flushing
+ * cpuset_migrate_mm_wq.
*/
+struct cpuset_migrate_mm_work {
+ struct work_struct work;
+ struct mm_struct *mm;
+ nodemask_t from;
+ nodemask_t to;
+};
+
+static void cpuset_migrate_mm_workfn(struct work_struct *work)
+{
+ struct cpuset_migrate_mm_work *mwork =
+ container_of(work, struct cpuset_migrate_mm_work, work);
+
+ /* on a wq worker, no need to worry about %current's mems_allowed */
+ do_migrate_pages(mwork->mm, &mwork->from, &mwork->to, MPOL_MF_MOVE_ALL);
+ mmput(mwork->mm);
+ kfree(mwork);
+}
+
static void cpuset_migrate_mm(struct mm_struct *mm, const nodemask_t *from,
const nodemask_t *to)
{
- struct task_struct *tsk = current;
+ struct cpuset_migrate_mm_work *mwork;
- tsk->mems_allowed = *to;
-
- do_migrate_pages(mm, from, to, MPOL_MF_MOVE_ALL);
+ mwork = kzalloc(sizeof(*mwork), GFP_KERNEL);
+ if (mwork) {
+ mwork->mm = mm;
+ mwork->from = *from;
+ mwork->to = *to;
+ INIT_WORK(&mwork->work, cpuset_migrate_mm_workfn);
+ queue_work(cpuset_migrate_mm_wq, &mwork->work);
+ } else {
+ mmput(mm);
+ }
+}
- rcu_read_lock();
- guarantee_online_mems(task_cs(tsk), &tsk->mems_allowed);
- rcu_read_unlock();
+void cpuset_post_attach_flush(void)
+{
+ flush_workqueue(cpuset_migrate_mm_wq);
}
/*
mpol_rebind_mm(mm, &cs->mems_allowed);
if (migrate)
cpuset_migrate_mm(mm, &cs->old_mems_allowed, &newmems);
- mmput(mm);
+ else
+ mmput(mm);
}
css_task_iter_end(&it);
* If it becomes empty, inherit the effective mask of the
* parent, which is guaranteed to have some MEMs.
*/
- if (cgroup_on_dfl(cp->css.cgroup) && nodes_empty(*new_mems))
+ if (cgroup_subsys_on_dfl(cpuset_cgrp_subsys) &&
+ nodes_empty(*new_mems))
*new_mems = parent->effective_mems;
/* Skip the whole subtree if the nodemask remains the same. */
cp->effective_mems = *new_mems;
spin_unlock_irq(&callback_lock);
- WARN_ON(!cgroup_on_dfl(cp->css.cgroup) &&
+ WARN_ON(!cgroup_subsys_on_dfl(cpuset_cgrp_subsys) &&
!nodes_equal(cp->mems_allowed, cp->effective_mems));
update_tasks_nodemask(cp);
static struct cpuset *cpuset_attach_old_cs;
/* Called by cgroups to determine if a cpuset is usable; cpuset_mutex held */
-static int cpuset_can_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static int cpuset_can_attach(struct cgroup_taskset *tset)
{
- struct cpuset *cs = css_cs(css);
+ struct cgroup_subsys_state *css;
+ struct cpuset *cs;
struct task_struct *task;
int ret;
/* used later by cpuset_attach() */
- cpuset_attach_old_cs = task_cs(cgroup_taskset_first(tset));
+ cpuset_attach_old_cs = task_cs(cgroup_taskset_first(tset, &css));
+ cs = css_cs(css);
mutex_lock(&cpuset_mutex);
/* allow moving tasks into an empty cpuset if on default hierarchy */
ret = -ENOSPC;
- if (!cgroup_on_dfl(css->cgroup) &&
+ if (!cgroup_subsys_on_dfl(cpuset_cgrp_subsys) &&
(cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed)))
goto out_unlock;
- cgroup_taskset_for_each(task, tset) {
+ cgroup_taskset_for_each(task, css, tset) {
ret = task_can_attach(task, cs->cpus_allowed);
if (ret)
goto out_unlock;
return ret;
}
-static void cpuset_cancel_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static void cpuset_cancel_attach(struct cgroup_taskset *tset)
{
+ struct cgroup_subsys_state *css;
+ struct cpuset *cs;
+
+ cgroup_taskset_first(tset, &css);
+ cs = css_cs(css);
+
mutex_lock(&cpuset_mutex);
css_cs(css)->attach_in_progress--;
mutex_unlock(&cpuset_mutex);
*/
static cpumask_var_t cpus_attach;
-static void cpuset_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static void cpuset_attach(struct cgroup_taskset *tset)
{
/* static buf protected by cpuset_mutex */
static nodemask_t cpuset_attach_nodemask_to;
- struct mm_struct *mm;
struct task_struct *task;
- struct task_struct *leader = cgroup_taskset_first(tset);
- struct cpuset *cs = css_cs(css);
+ struct task_struct *leader;
+ struct cgroup_subsys_state *css;
+ struct cpuset *cs;
struct cpuset *oldcs = cpuset_attach_old_cs;
+ cgroup_taskset_first(tset, &css);
+ cs = css_cs(css);
+
mutex_lock(&cpuset_mutex);
/* prepare for attach */
guarantee_online_mems(cs, &cpuset_attach_nodemask_to);
- cgroup_taskset_for_each(task, tset) {
+ cgroup_taskset_for_each(task, css, tset) {
/*
* can_attach beforehand should guarantee that this doesn't
* fail. TODO: have a better way to handle failure here
}
/*
- * Change mm, possibly for multiple threads in a threadgroup. This is
- * expensive and may sleep.
+ * Change mm for all threadgroup leaders. This is expensive and may
+ * sleep and should be moved outside migration path proper.
*/
cpuset_attach_nodemask_to = cs->effective_mems;
- mm = get_task_mm(leader);
- if (mm) {
- mpol_rebind_mm(mm, &cpuset_attach_nodemask_to);
-
- /*
- * old_mems_allowed is the same with mems_allowed here, except
- * if this task is being moved automatically due to hotplug.
- * In that case @mems_allowed has been updated and is empty,
- * so @old_mems_allowed is the right nodesets that we migrate
- * mm from.
- */
- if (is_memory_migrate(cs)) {
- cpuset_migrate_mm(mm, &oldcs->old_mems_allowed,
- &cpuset_attach_nodemask_to);
+ cgroup_taskset_for_each_leader(leader, css, tset) {
+ struct mm_struct *mm = get_task_mm(leader);
+
+ if (mm) {
+ mpol_rebind_mm(mm, &cpuset_attach_nodemask_to);
+
+ /*
+ * old_mems_allowed is the same with mems_allowed
+ * here, except if this task is being moved
+ * automatically due to hotplug. In that case
+ * @mems_allowed has been updated and is empty, so
+ * @old_mems_allowed is the right nodesets that we
+ * migrate mm from.
+ */
+ if (is_memory_migrate(cs))
+ cpuset_migrate_mm(mm, &oldcs->old_mems_allowed,
+ &cpuset_attach_nodemask_to);
+ else
+ mmput(mm);
}
- mmput(mm);
}
cs->old_mems_allowed = cpuset_attach_nodemask_to;
case FILE_MEMORY_PRESSURE_ENABLED:
cpuset_memory_pressure_enabled = !!val;
break;
- case FILE_MEMORY_PRESSURE:
- retval = -EACCES;
- break;
case FILE_SPREAD_PAGE:
retval = update_flag(CS_SPREAD_PAGE, cs, val);
break;
mutex_unlock(&cpuset_mutex);
kernfs_unbreak_active_protection(of->kn);
css_put(&cs->css);
+ flush_workqueue(cpuset_migrate_mm_wq);
return retval ?: nbytes;
}
{
.name = "memory_pressure",
.read_u64 = cpuset_read_u64,
- .write_u64 = cpuset_write_u64,
- .private = FILE_MEMORY_PRESSURE,
- .mode = S_IRUGO,
},
{
cpuset_inc();
spin_lock_irq(&callback_lock);
- if (cgroup_on_dfl(cs->css.cgroup)) {
+ if (cgroup_subsys_on_dfl(cpuset_cgrp_subsys)) {
cpumask_copy(cs->effective_cpus, parent->effective_cpus);
cs->effective_mems = parent->effective_mems;
}
mutex_lock(&cpuset_mutex);
spin_lock_irq(&callback_lock);
- if (cgroup_on_dfl(root_css->cgroup)) {
+ if (cgroup_subsys_on_dfl(cpuset_cgrp_subsys)) {
cpumask_copy(top_cpuset.cpus_allowed, cpu_possible_mask);
top_cpuset.mems_allowed = node_possible_map;
} else {
cpus_updated = !cpumask_equal(&new_cpus, cs->effective_cpus);
mems_updated = !nodes_equal(new_mems, cs->effective_mems);
- if (cgroup_on_dfl(cs->css.cgroup))
+ if (cgroup_subsys_on_dfl(cpuset_cgrp_subsys))
hotplug_update_tasks(cs, &new_cpus, &new_mems,
cpus_updated, mems_updated);
else
static cpumask_t new_cpus;
static nodemask_t new_mems;
bool cpus_updated, mems_updated;
- bool on_dfl = cgroup_on_dfl(top_cpuset.css.cgroup);
+ bool on_dfl = cgroup_subsys_on_dfl(cpuset_cgrp_subsys);
mutex_lock(&cpuset_mutex);
top_cpuset.effective_mems = node_states[N_MEMORY];
register_hotmemory_notifier(&cpuset_track_online_nodes_nb);
+
+ cpuset_migrate_mm_wq = alloc_ordered_workqueue("cpuset_migrate_mm", 0);
+ BUG_ON(!cpuset_migrate_mm_wq);
}
/**
}
/**
- * cpuset_print_task_mems_allowed - prints task's cpuset and mems_allowed
- * @tsk: pointer to task_struct of some task.
+ * cpuset_print_current_mems_allowed - prints current's cpuset and mems_allowed
*
- * Description: Prints @task's name, cpuset name, and cached copy of its
+ * Description: Prints current's name, cpuset name, and cached copy of its
* mems_allowed to the kernel log.
*/
-void cpuset_print_task_mems_allowed(struct task_struct *tsk)
+void cpuset_print_current_mems_allowed(void)
{
struct cgroup *cgrp;
rcu_read_lock();
- cgrp = task_cs(tsk)->css.cgroup;
- pr_info("%s cpuset=", tsk->comm);
+ cgrp = task_cs(current)->css.cgroup;
+ pr_info("%s cpuset=", current->comm);
pr_cont_cgroup_name(cgrp);
- pr_cont(" mems_allowed=%*pbl\n", nodemask_pr_args(&tsk->mems_allowed));
+ pr_cont(" mems_allowed=%*pbl\n",
+ nodemask_pr_args(¤t->mems_allowed));
rcu_read_unlock();
}
Code Review / kvmfornfv.git / blobdiff