Commit ae1c8023 authored by Li Zefan's avatar Li Zefan Committed by Tejun Heo

cpuset: apply cs->effective_{cpus,mems}

Now we can use cs->effective_{cpus,mems} as effective masks. It's
used whenever:

- we update tasks' cpus_allowed/mems_allowed,
- we want to retrieve tasks_cs(tsk)'s cpus_allowed/mems_allowed.

They actually replace effective_{cpu,node}mask_cpuset().

effective_mask == configured_mask & parent effective_mask except when
the reault is empty, in which case it inherits parent effective_mask.
The result equals the mask computed from effective_{cpu,node}mask_cpuset().

This won't affect the original legacy hierarchy, because in this case we
make sure the effective masks are always the same with user-configured
masks.
Signed-off-by: default avatarLi Zefan <lizefan@huawei.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 39bd0d15
......@@ -313,9 +313,9 @@ static struct file_system_type cpuset_fs_type = {
*/
static void guarantee_online_cpus(struct cpuset *cs, struct cpumask *pmask)
{
while (!cpumask_intersects(cs->cpus_allowed, cpu_online_mask))
while (!cpumask_intersects(cs->effective_cpus, cpu_online_mask))
cs = parent_cs(cs);
cpumask_and(pmask, cs->cpus_allowed, cpu_online_mask);
cpumask_and(pmask, cs->effective_cpus, cpu_online_mask);
}
/*
......@@ -331,9 +331,9 @@ static void guarantee_online_cpus(struct cpuset *cs, struct cpumask *pmask)
*/
static void guarantee_online_mems(struct cpuset *cs, nodemask_t *pmask)
{
while (!nodes_intersects(cs->mems_allowed, node_states[N_MEMORY]))
while (!nodes_intersects(cs->effective_mems, node_states[N_MEMORY]))
cs = parent_cs(cs);
nodes_and(*pmask, cs->mems_allowed, node_states[N_MEMORY]);
nodes_and(*pmask, cs->effective_mems, node_states[N_MEMORY]);
}
/*
......@@ -795,45 +795,6 @@ void rebuild_sched_domains(void)
mutex_unlock(&cpuset_mutex);
}
/*
* effective_cpumask_cpuset - return nearest ancestor with non-empty cpus
* @cs: the cpuset in interest
*
* A cpuset's effective cpumask is the cpumask of the nearest ancestor
* with non-empty cpus. We use effective cpumask whenever:
* - we update tasks' cpus_allowed. (they take on the ancestor's cpumask
* if the cpuset they reside in has no cpus)
* - we want to retrieve task_cs(tsk)'s cpus_allowed.
*
* Called with cpuset_mutex held. cpuset_cpus_allowed_fallback() is an
* exception. See comments there.
*/
static struct cpuset *effective_cpumask_cpuset(struct cpuset *cs)
{
while (cpumask_empty(cs->cpus_allowed))
cs = parent_cs(cs);
return cs;
}
/*
* effective_nodemask_cpuset - return nearest ancestor with non-empty mems
* @cs: the cpuset in interest
*
* A cpuset's effective nodemask is the nodemask of the nearest ancestor
* with non-empty memss. We use effective nodemask whenever:
* - we update tasks' mems_allowed. (they take on the ancestor's nodemask
* if the cpuset they reside in has no mems)
* - we want to retrieve task_cs(tsk)'s mems_allowed.
*
* Called with cpuset_mutex held.
*/
static struct cpuset *effective_nodemask_cpuset(struct cpuset *cs)
{
while (nodes_empty(cs->mems_allowed))
cs = parent_cs(cs);
return cs;
}
/**
* update_tasks_cpumask - Update the cpumasks of tasks in the cpuset.
* @cs: the cpuset in which each task's cpus_allowed mask needs to be changed
......@@ -844,13 +805,12 @@ static struct cpuset *effective_nodemask_cpuset(struct cpuset *cs)
*/
static void update_tasks_cpumask(struct cpuset *cs)
{
struct cpuset *cpus_cs = effective_cpumask_cpuset(cs);
struct css_task_iter it;
struct task_struct *task;
css_task_iter_start(&cs->css, &it);
while ((task = css_task_iter_next(&it)))
set_cpus_allowed_ptr(task, cpus_cs->cpus_allowed);
set_cpus_allowed_ptr(task, cs->effective_cpus);
css_task_iter_end(&it);
}
......@@ -988,15 +948,13 @@ static void cpuset_migrate_mm(struct mm_struct *mm, const nodemask_t *from,
const nodemask_t *to)
{
struct task_struct *tsk = current;
struct cpuset *mems_cs;
tsk->mems_allowed = *to;
do_migrate_pages(mm, from, to, MPOL_MF_MOVE_ALL);
rcu_read_lock();
mems_cs = effective_nodemask_cpuset(task_cs(tsk));
guarantee_online_mems(mems_cs, &tsk->mems_allowed);
guarantee_online_mems(task_cs(tsk), &tsk->mems_allowed);
rcu_read_unlock();
}
......@@ -1065,13 +1023,12 @@ static void *cpuset_being_rebound;
static void update_tasks_nodemask(struct cpuset *cs)
{
static nodemask_t newmems; /* protected by cpuset_mutex */
struct cpuset *mems_cs = effective_nodemask_cpuset(cs);
struct css_task_iter it;
struct task_struct *task;
cpuset_being_rebound = cs; /* causes mpol_dup() rebind */
guarantee_online_mems(mems_cs, &newmems);
guarantee_online_mems(cs, &newmems);
/*
* The mpol_rebind_mm() call takes mmap_sem, which we couldn't
......@@ -1497,8 +1454,6 @@ static void cpuset_attach(struct cgroup_subsys_state *css,
struct task_struct *leader = cgroup_taskset_first(tset);
struct cpuset *cs = css_cs(css);
struct cpuset *oldcs = cpuset_attach_old_cs;
struct cpuset *cpus_cs = effective_cpumask_cpuset(cs);
struct cpuset *mems_cs = effective_nodemask_cpuset(cs);
mutex_lock(&cpuset_mutex);
......@@ -1506,9 +1461,9 @@ static void cpuset_attach(struct cgroup_subsys_state *css,
if (cs == &top_cpuset)
cpumask_copy(cpus_attach, cpu_possible_mask);
else
guarantee_online_cpus(cpus_cs, cpus_attach);
guarantee_online_cpus(cs, cpus_attach);
guarantee_online_mems(mems_cs, &cpuset_attach_nodemask_to);
guarantee_online_mems(cs, &cpuset_attach_nodemask_to);
cgroup_taskset_for_each(task, tset) {
/*
......@@ -1525,11 +1480,9 @@ static void cpuset_attach(struct cgroup_subsys_state *css,
* Change mm, possibly for multiple threads in a threadgroup. This is
* expensive and may sleep.
*/
cpuset_attach_nodemask_to = cs->mems_allowed;
cpuset_attach_nodemask_to = cs->effective_mems;
mm = get_task_mm(leader);
if (mm) {
struct cpuset *mems_oldcs = effective_nodemask_cpuset(oldcs);
mpol_rebind_mm(mm, &cpuset_attach_nodemask_to);
/*
......@@ -1540,7 +1493,7 @@ static void cpuset_attach(struct cgroup_subsys_state *css,
* mm from.
*/
if (is_memory_migrate(cs)) {
cpuset_migrate_mm(mm, &mems_oldcs->old_mems_allowed,
cpuset_migrate_mm(mm, &oldcs->old_mems_allowed,
&cpuset_attach_nodemask_to);
}
mmput(mm);
......@@ -2331,23 +2284,17 @@ void __init cpuset_init_smp(void)
void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask)
{
struct cpuset *cpus_cs;
mutex_lock(&callback_mutex);
rcu_read_lock();
cpus_cs = effective_cpumask_cpuset(task_cs(tsk));
guarantee_online_cpus(cpus_cs, pmask);
guarantee_online_cpus(task_cs(tsk), pmask);
rcu_read_unlock();
mutex_unlock(&callback_mutex);
}
void cpuset_cpus_allowed_fallback(struct task_struct *tsk)
{
struct cpuset *cpus_cs;
rcu_read_lock();
cpus_cs = effective_cpumask_cpuset(task_cs(tsk));
do_set_cpus_allowed(tsk, cpus_cs->cpus_allowed);
do_set_cpus_allowed(tsk, task_cs(tsk)->effective_cpus);
rcu_read_unlock();
/*
......@@ -2386,13 +2333,11 @@ void cpuset_init_current_mems_allowed(void)
nodemask_t cpuset_mems_allowed(struct task_struct *tsk)
{
struct cpuset *mems_cs;
nodemask_t mask;
mutex_lock(&callback_mutex);
rcu_read_lock();
mems_cs = effective_nodemask_cpuset(task_cs(tsk));
guarantee_online_mems(mems_cs, &mask);
guarantee_online_mems(task_cs(tsk), &mask);
rcu_read_unlock();
mutex_unlock(&callback_mutex);
......
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