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cgroup/cpuset: move legacy hotplug update to cpuset-v1.c

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There are some differents about hotplug update between cpuset v1 and
cpuset v2. Move the legacy code to cpuset-v1.c.

'update_tasks_cpumask' and 'update_tasks_nodemask' are both used in cpuset
v1 and cpuset v2, declare them in cpuset-internal.h.

The change from original code is that use callback_lock helpers to get
callback_lock lock/unlock.

Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Chen Ridong
2024-08-30 10:02:24 +00:00
committed by Tejun Heo
parent 530020f28f
commit 23ca5237e3
3 changed files with 98 additions and 94 deletions
Download Patch File Download Diff File Expand all files Collapse all files
kernel/cgroup/cpuset-internal.h
+5
View File
@@ -241,6 +241,8 @@ static inline int is_spread_slab(const struct cpuset *cs)
void rebuild_sched_domains_locked(void);
void callback_lock_irq(void);
void callback_unlock_irq(void);
void update_tasks_cpumask(struct cpuset *cs, struct cpumask *new_cpus);
void update_tasks_nodemask(struct cpuset *cs);
/*
* cpuset-v1.c
@@ -253,5 +255,8 @@ s64 cpuset_read_s64(struct cgroup_subsys_state *css, struct cftype *cft);
void cpuset_update_task_spread_flags(struct cpuset *cs,
struct task_struct *tsk);
void update_tasks_flags(struct cpuset *cs);
void hotplug_update_tasks_legacy(struct cpuset *cs,
struct cpumask *new_cpus, nodemask_t *new_mems,
bool cpus_updated, bool mems_updated);
#endif /* __CPUSET_INTERNAL_H */
kernel/cgroup/cpuset-v1.c
+91
View File
@@ -2,6 +2,14 @@
#include "cpuset-internal.h"
/*
* Legacy hierarchy call to cgroup_transfer_tasks() is handled asynchrously
*/
struct cpuset_remove_tasks_struct {
struct work_struct work;
struct cpuset *cs;
};
/*
* Frequency meter - How fast is some event occurring?
*
@@ -236,3 +244,86 @@ void update_tasks_flags(struct cpuset *cs)
cpuset_update_task_spread_flags(cs, task);
css_task_iter_end(&it);
}
/*
* If CPU and/or memory hotplug handlers, below, unplug any CPUs
* or memory nodes, we need to walk over the cpuset hierarchy,
* removing that CPU or node from all cpusets. If this removes the
* last CPU or node from a cpuset, then move the tasks in the empty
* cpuset to its next-highest non-empty parent.
*/
static void remove_tasks_in_empty_cpuset(struct cpuset *cs)
{
struct cpuset *parent;
/*
* Find its next-highest non-empty parent, (top cpuset
* has online cpus, so can't be empty).
*/
parent = parent_cs(cs);
while (cpumask_empty(parent->cpus_allowed) ||
nodes_empty(parent->mems_allowed))
parent = parent_cs(parent);
if (cgroup_transfer_tasks(parent->css.cgroup, cs->css.cgroup)) {
pr_err("cpuset: failed to transfer tasks out of empty cpuset ");
pr_cont_cgroup_name(cs->css.cgroup);
pr_cont("\n");
}
}
static void cpuset_migrate_tasks_workfn(struct work_struct *work)
{
struct cpuset_remove_tasks_struct *s;
s = container_of(work, struct cpuset_remove_tasks_struct, work);
remove_tasks_in_empty_cpuset(s->cs);
css_put(&s->cs->css);
kfree(s);
}
void hotplug_update_tasks_legacy(struct cpuset *cs,
struct cpumask *new_cpus, nodemask_t *new_mems,
bool cpus_updated, bool mems_updated)
{
bool is_empty;
callback_lock_irq();
cpumask_copy(cs->cpus_allowed, new_cpus);
cpumask_copy(cs->effective_cpus, new_cpus);
cs->mems_allowed = *new_mems;
cs->effective_mems = *new_mems;
callback_unlock_irq();
/*
* Don't call update_tasks_cpumask() if the cpuset becomes empty,
* as the tasks will be migrated to an ancestor.
*/
if (cpus_updated && !cpumask_empty(cs->cpus_allowed))
update_tasks_cpumask(cs, new_cpus);
if (mems_updated && !nodes_empty(cs->mems_allowed))
update_tasks_nodemask(cs);
is_empty = cpumask_empty(cs->cpus_allowed) ||
nodes_empty(cs->mems_allowed);
/*
* Move tasks to the nearest ancestor with execution resources,
* This is full cgroup operation which will also call back into
* cpuset. Execute it asynchronously using workqueue.
*/
if (is_empty && cs->css.cgroup->nr_populated_csets &&
css_tryget_online(&cs->css)) {
struct cpuset_remove_tasks_struct *s;
s = kzalloc(sizeof(*s), GFP_KERNEL);
if (WARN_ON_ONCE(!s)) {
css_put(&cs->css);
return;
}
s->cs = cs;
INIT_WORK(&s->work, cpuset_migrate_tasks_workfn);
schedule_work(&s->work);
}
}
kernel/cgroup/cpuset.c
+2 -94
View File
@@ -65,14 +65,6 @@ static const char * const perr_strings[] = {
[PERR_ACCESS] = "Enable partition not permitted",
};
/*
* Legacy hierarchy call to cgroup_transfer_tasks() is handled asynchrously
*/
struct cpuset_remove_tasks_struct {
struct work_struct work;
struct cpuset *cs;
};
/*
* Exclusive CPUs distributed out to sub-partitions of top_cpuset
*/
@@ -1144,7 +1136,7 @@ void rebuild_sched_domains(void)
* is used instead of effective_cpus to make sure all offline CPUs are also
* included as hotplug code won't update cpumasks for tasks in top_cpuset.
*/
static void update_tasks_cpumask(struct cpuset *cs, struct cpumask *new_cpus)
void update_tasks_cpumask(struct cpuset *cs, struct cpumask *new_cpus)
{
struct css_task_iter it;
struct task_struct *task;
@@ -2597,7 +2589,7 @@ static void *cpuset_being_rebound;
* effective cpuset's. As this function is called with cpuset_mutex held,
* cpuset membership stays stable.
*/
static void update_tasks_nodemask(struct cpuset *cs)
void update_tasks_nodemask(struct cpuset *cs)
{
static nodemask_t newmems; /* protected by cpuset_mutex */
struct css_task_iter it;
@@ -3936,90 +3928,6 @@ int __init cpuset_init(void)
return 0;
}
/*
* If CPU and/or memory hotplug handlers, below, unplug any CPUs
* or memory nodes, we need to walk over the cpuset hierarchy,
* removing that CPU or node from all cpusets. If this removes the
* last CPU or node from a cpuset, then move the tasks in the empty
* cpuset to its next-highest non-empty parent.
*/
static void remove_tasks_in_empty_cpuset(struct cpuset *cs)
{
struct cpuset *parent;
/*
* Find its next-highest non-empty parent, (top cpuset
* has online cpus, so can't be empty).
*/
parent = parent_cs(cs);
while (cpumask_empty(parent->cpus_allowed) ||
nodes_empty(parent->mems_allowed))
parent = parent_cs(parent);
if (cgroup_transfer_tasks(parent->css.cgroup, cs->css.cgroup)) {
pr_err("cpuset: failed to transfer tasks out of empty cpuset ");
pr_cont_cgroup_name(cs->css.cgroup);
pr_cont("\n");
}
}
static void cpuset_migrate_tasks_workfn(struct work_struct *work)
{
struct cpuset_remove_tasks_struct *s;
s = container_of(work, struct cpuset_remove_tasks_struct, work);
remove_tasks_in_empty_cpuset(s->cs);
css_put(&s->cs->css);
kfree(s);
}
static void
hotplug_update_tasks_legacy(struct cpuset *cs,
struct cpumask *new_cpus, nodemask_t *new_mems,
bool cpus_updated, bool mems_updated)
{
bool is_empty;
spin_lock_irq(&callback_lock);
cpumask_copy(cs->cpus_allowed, new_cpus);
cpumask_copy(cs->effective_cpus, new_cpus);
cs->mems_allowed = *new_mems;
cs->effective_mems = *new_mems;
spin_unlock_irq(&callback_lock);
/*
* Don't call update_tasks_cpumask() if the cpuset becomes empty,
* as the tasks will be migrated to an ancestor.
*/
if (cpus_updated && !cpumask_empty(cs->cpus_allowed))
update_tasks_cpumask(cs, new_cpus);
if (mems_updated && !nodes_empty(cs->mems_allowed))
update_tasks_nodemask(cs);
is_empty = cpumask_empty(cs->cpus_allowed) ||
nodes_empty(cs->mems_allowed);
/*
* Move tasks to the nearest ancestor with execution resources,
* This is full cgroup operation which will also call back into
* cpuset. Execute it asynchronously using workqueue.
*/
if (is_empty && cs->css.cgroup->nr_populated_csets &&
css_tryget_online(&cs->css)) {
struct cpuset_remove_tasks_struct *s;
s = kzalloc(sizeof(*s), GFP_KERNEL);
if (WARN_ON_ONCE(!s)) {
css_put(&cs->css);
return;
}
s->cs = cs;
INIT_WORK(&s->work, cpuset_migrate_tasks_workfn);
schedule_work(&s->work);
}
}
static void
hotplug_update_tasks(struct cpuset *cs,
struct cpumask *new_cpus, nodemask_t *new_mems,