Merge branch 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

[sfrench/cifs-2.6.git] / kernel / cgroup / cpuset.c

diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index e7485786db9b3e8e881d045028d288d3b0cb71b1..67230ecf2ce155a36a045b0bb1c080224521a63a 100644 (file)
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -300,6 +300,16 @@ static DECLARE_WORK(cpuset_hotplug_work, cpuset_hotplug_workfn);
 
 static DECLARE_WAIT_QUEUE_HEAD(cpuset_attach_wq);
 
+/*
+ * Cgroup v2 behavior is used when on default hierarchy or the
+ * cgroup_v2_mode flag is set.
+ */
+static inline bool is_in_v2_mode(void)
+{
+       return cgroup_subsys_on_dfl(cpuset_cgrp_subsys) ||
+             (cpuset_cgrp_subsys.root->flags & CGRP_ROOT_CPUSET_V2_MODE);
+}
+
 /*
  * This is ugly, but preserves the userspace API for existing cpuset
  * users. If someone tries to mount the "cpuset" filesystem, we
@@ -490,8 +500,7 @@ static int validate_change(struct cpuset *cur, struct cpuset *trial)
 
        /* On legacy hiearchy, we must be a subset of our parent cpuset. */
        ret = -EACCES;
-       if (!cgroup_subsys_on_dfl(cpuset_cgrp_subsys) &&
-           !is_cpuset_subset(trial, par))
+       if (!is_in_v2_mode() && !is_cpuset_subset(trial, par))
                goto out;
 
        /*
@@ -870,7 +879,7 @@ static void update_tasks_cpumask(struct cpuset *cs)
        struct css_task_iter it;
        struct task_struct *task;
 
-       css_task_iter_start(&cs->css, &it);
+       css_task_iter_start(&cs->css, 0, &it);
        while ((task = css_task_iter_next(&it)))
                set_cpus_allowed_ptr(task, cs->effective_cpus);
        css_task_iter_end(&it);
@@ -904,8 +913,7 @@ static void update_cpumasks_hier(struct cpuset *cs, struct cpumask *new_cpus)
                 * If it becomes empty, inherit the effective mask of the
                 * parent, which is guaranteed to have some CPUs.
                 */
-               if (cgroup_subsys_on_dfl(cpuset_cgrp_subsys) &&
-                   cpumask_empty(new_cpus))
+               if (is_in_v2_mode() && cpumask_empty(new_cpus))
                        cpumask_copy(new_cpus, parent->effective_cpus);
 
                /* Skip the whole subtree if the cpumask remains the same. */
@@ -922,7 +930,7 @@ static void update_cpumasks_hier(struct cpuset *cs, struct cpumask *new_cpus)
                cpumask_copy(cp->effective_cpus, new_cpus);
                spin_unlock_irq(&callback_lock);
 
-               WARN_ON(!cgroup_subsys_on_dfl(cpuset_cgrp_subsys) &&
+               WARN_ON(!is_in_v2_mode() &&
                        !cpumask_equal(cp->cpus_allowed, cp->effective_cpus));
 
                update_tasks_cpumask(cp);
@@ -1100,7 +1108,7 @@ static void update_tasks_nodemask(struct cpuset *cs)
         * It's ok if we rebind the same mm twice; mpol_rebind_mm()
         * is idempotent.  Also migrate pages in each mm to new nodes.
         */
-       css_task_iter_start(&cs->css, &it);
+       css_task_iter_start(&cs->css, 0, &it);
        while ((task = css_task_iter_next(&it))) {
                struct mm_struct *mm;
                bool migrate;
@@ -1158,8 +1166,7 @@ static void update_nodemasks_hier(struct cpuset *cs, nodemask_t *new_mems)
                 * If it becomes empty, inherit the effective mask of the
                 * parent, which is guaranteed to have some MEMs.
                 */
-               if (cgroup_subsys_on_dfl(cpuset_cgrp_subsys) &&
-                   nodes_empty(*new_mems))
+               if (is_in_v2_mode() && nodes_empty(*new_mems))
                        *new_mems = parent->effective_mems;
 
                /* Skip the whole subtree if the nodemask remains the same. */
@@ -1176,7 +1183,7 @@ static void update_nodemasks_hier(struct cpuset *cs, nodemask_t *new_mems)
                cp->effective_mems = *new_mems;
                spin_unlock_irq(&callback_lock);
 
-               WARN_ON(!cgroup_subsys_on_dfl(cpuset_cgrp_subsys) &&
+               WARN_ON(!is_in_v2_mode() &&
                        !nodes_equal(cp->mems_allowed, cp->effective_mems));
 
                update_tasks_nodemask(cp);
@@ -1293,7 +1300,7 @@ static void update_tasks_flags(struct cpuset *cs)
        struct css_task_iter it;
        struct task_struct *task;
 
-       css_task_iter_start(&cs->css, &it);
+       css_task_iter_start(&cs->css, 0, &it);
        while ((task = css_task_iter_next(&it)))
                cpuset_update_task_spread_flag(cs, task);
        css_task_iter_end(&it);
@@ -1468,7 +1475,7 @@ static int cpuset_can_attach(struct cgroup_taskset *tset)
 
        /* allow moving tasks into an empty cpuset if on default hierarchy */
        ret = -ENOSPC;
-       if (!cgroup_subsys_on_dfl(cpuset_cgrp_subsys) &&
+       if (!is_in_v2_mode() &&
            (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed)))
                goto out_unlock;
 
@@ -1987,7 +1994,7 @@ static int cpuset_css_online(struct cgroup_subsys_state *css)
        cpuset_inc();
 
        spin_lock_irq(&callback_lock);
-       if (cgroup_subsys_on_dfl(cpuset_cgrp_subsys)) {
+       if (is_in_v2_mode()) {
                cpumask_copy(cs->effective_cpus, parent->effective_cpus);
                cs->effective_mems = parent->effective_mems;
        }
@@ -2064,7 +2071,7 @@ static void cpuset_bind(struct cgroup_subsys_state *root_css)
        mutex_lock(&cpuset_mutex);
        spin_lock_irq(&callback_lock);
 
-       if (cgroup_subsys_on_dfl(cpuset_cgrp_subsys)) {
+       if (is_in_v2_mode()) {
                cpumask_copy(top_cpuset.cpus_allowed, cpu_possible_mask);
                top_cpuset.mems_allowed = node_possible_map;
        } else {
@@ -2258,7 +2265,7 @@ retry:
        cpus_updated = !cpumask_equal(&new_cpus, cs->effective_cpus);
        mems_updated = !nodes_equal(new_mems, cs->effective_mems);
 
-       if (cgroup_subsys_on_dfl(cpuset_cgrp_subsys))
+       if (is_in_v2_mode())
                hotplug_update_tasks(cs, &new_cpus, &new_mems,
                                     cpus_updated, mems_updated);
        else
@@ -2289,7 +2296,7 @@ static void cpuset_hotplug_workfn(struct work_struct *work)
        static cpumask_t new_cpus;
        static nodemask_t new_mems;
        bool cpus_updated, mems_updated;
-       bool on_dfl = cgroup_subsys_on_dfl(cpuset_cgrp_subsys);
+       bool on_dfl = is_in_v2_mode();
 
        mutex_lock(&cpuset_mutex);