use_parent_ecpus is used to track whether the children are using the
parent's effective_cpus. When a parent's effective_cpus is changed
due to changes in a child partition's effective_xcpus, any child
using parent'effective_cpus must call update_cpumasks_hier. However,
if a child is not a valid partition, it is sufficient to determine
whether to call update_cpumasks_hier based on whether the child's
effective_cpus is going to change. To make the code more succinct,
it is suggested to remove use_parent_ecpus.
Signed-off-by: Chen Ridong <chenridong@huawei.com>
---
kernel/cgroup/cpuset.c | 30 ++++--------------------------
1 file changed, 4 insertions(+), 26 deletions(-)
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 8be0259065f5..71c24542966b 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -185,12 +185,6 @@ struct cpuset {
/* partition root state */
int partition_root_state;
- /*
- * Default hierarchy only:
- * use_parent_ecpus - set if using parent's effective_cpus
- */
- int use_parent_ecpus;
-
/*
* number of SCHED_DEADLINE tasks attached to this cpuset, so that we
* know when to rebuild associated root domain bandwidth information.
@@ -1505,11 +1499,8 @@ static void reset_partition_data(struct cpuset *cs)
if (is_cpu_exclusive(cs))
clear_bit(CS_CPU_EXCLUSIVE, &cs->flags);
}
- if (!cpumask_and(cs->effective_cpus,
- parent->effective_cpus, cs->cpus_allowed)) {
- cs->use_parent_ecpus = true;
+ if (!cpumask_and(cs->effective_cpus, parent->effective_cpus, cs->cpus_allowed))
cpumask_copy(cs->effective_cpus, parent->effective_cpus);
- }
}
/*
@@ -1683,8 +1674,6 @@ static int remote_partition_enable(struct cpuset *cs, int new_prs,
spin_lock_irq(&callback_lock);
isolcpus_updated = partition_xcpus_add(new_prs, NULL, tmp->new_cpus);
list_add(&cs->remote_sibling, &remote_children);
- if (cs->use_parent_ecpus)
- cs->use_parent_ecpus = false;
spin_unlock_irq(&callback_lock);
update_unbound_workqueue_cpumask(isolcpus_updated);
@@ -2309,13 +2298,8 @@ static void update_cpumasks_hier(struct cpuset *cs, struct tmpmasks *tmp,
* it is a partition root that has explicitly distributed
* out all its CPUs.
*/
- if (is_in_v2_mode() && !remote && cpumask_empty(tmp->new_cpus)) {
+ if (is_in_v2_mode() && !remote && cpumask_empty(tmp->new_cpus))
cpumask_copy(tmp->new_cpus, parent->effective_cpus);
- if (!cp->use_parent_ecpus)
- cp->use_parent_ecpus = true;
- } else if (cp->use_parent_ecpus) {
- cp->use_parent_ecpus = false;
- }
if (remote)
goto get_css;
@@ -2452,8 +2436,7 @@ static void update_sibling_cpumasks(struct cpuset *parent, struct cpuset *cs,
* Check all its siblings and call update_cpumasks_hier()
* if their effective_cpus will need to be changed.
*
- * With the addition of effective_xcpus which is a subset of
- * cpus_allowed. It is possible a change in parent's effective_cpus
+ * It is possible a change in parent's effective_cpus
* due to a change in a child partition's effective_xcpus will impact
* its siblings even if they do not inherit parent's effective_cpus
* directly.
@@ -2467,8 +2450,7 @@ static void update_sibling_cpumasks(struct cpuset *parent, struct cpuset *cs,
cpuset_for_each_child(sibling, pos_css, parent) {
if (sibling == cs)
continue;
- if (!sibling->use_parent_ecpus &&
- !is_partition_valid(sibling)) {
+ if (!is_partition_valid(sibling)) {
compute_effective_cpumask(tmp->new_cpus, sibling,
parent);
if (cpumask_equal(tmp->new_cpus, sibling->effective_cpus))
@@ -4128,7 +4110,6 @@ static int cpuset_css_online(struct cgroup_subsys_state *css)
if (is_in_v2_mode()) {
cpumask_copy(cs->effective_cpus, parent->effective_cpus);
cs->effective_mems = parent->effective_mems;
- cs->use_parent_ecpus = true;
}
spin_unlock_irq(&callback_lock);
@@ -4194,9 +4175,6 @@ static void cpuset_css_offline(struct cgroup_subsys_state *css)
is_sched_load_balance(cs))
update_flag(CS_SCHED_LOAD_BALANCE, cs, 0);
- if (cs->use_parent_ecpus)
- cs->use_parent_ecpus = false;
-
cpuset_dec();
clear_bit(CS_ONLINE, &cs->flags);
--
2.34.1On 8/16/24 04:27, Chen Ridong wrote:
> use_parent_ecpus is used to track whether the children are using the
> parent's effective_cpus. When a parent's effective_cpus is changed
> due to changes in a child partition's effective_xcpus, any child
> using parent'effective_cpus must call update_cpumasks_hier. However,
> if a child is not a valid partition, it is sufficient to determine
> whether to call update_cpumasks_hier based on whether the child's
> effective_cpus is going to change. To make the code more succinct,
> it is suggested to remove use_parent_ecpus.
>
> Signed-off-by: Chen Ridong <chenridong@huawei.com>
> ---
> kernel/cgroup/cpuset.c | 30 ++++--------------------------
> 1 file changed, 4 insertions(+), 26 deletions(-)
>
> diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
> index 8be0259065f5..71c24542966b 100644
> --- a/kernel/cgroup/cpuset.c
> +++ b/kernel/cgroup/cpuset.c
> @@ -185,12 +185,6 @@ struct cpuset {
> /* partition root state */
> int partition_root_state;
>
> - /*
> - * Default hierarchy only:
> - * use_parent_ecpus - set if using parent's effective_cpus
> - */
> - int use_parent_ecpus;
> -
> /*
> * number of SCHED_DEADLINE tasks attached to this cpuset, so that we
> * know when to rebuild associated root domain bandwidth information.
> @@ -1505,11 +1499,8 @@ static void reset_partition_data(struct cpuset *cs)
> if (is_cpu_exclusive(cs))
> clear_bit(CS_CPU_EXCLUSIVE, &cs->flags);
> }
> - if (!cpumask_and(cs->effective_cpus,
> - parent->effective_cpus, cs->cpus_allowed)) {
> - cs->use_parent_ecpus = true;
> + if (!cpumask_and(cs->effective_cpus, parent->effective_cpus, cs->cpus_allowed))
> cpumask_copy(cs->effective_cpus, parent->effective_cpus);
> - }
> }
>
> /*
> @@ -1683,8 +1674,6 @@ static int remote_partition_enable(struct cpuset *cs, int new_prs,
> spin_lock_irq(&callback_lock);
> isolcpus_updated = partition_xcpus_add(new_prs, NULL, tmp->new_cpus);
> list_add(&cs->remote_sibling, &remote_children);
> - if (cs->use_parent_ecpus)
> - cs->use_parent_ecpus = false;
> spin_unlock_irq(&callback_lock);
> update_unbound_workqueue_cpumask(isolcpus_updated);
>
> @@ -2309,13 +2298,8 @@ static void update_cpumasks_hier(struct cpuset *cs, struct tmpmasks *tmp,
> * it is a partition root that has explicitly distributed
> * out all its CPUs.
> */
> - if (is_in_v2_mode() && !remote && cpumask_empty(tmp->new_cpus)) {
> + if (is_in_v2_mode() && !remote && cpumask_empty(tmp->new_cpus))
> cpumask_copy(tmp->new_cpus, parent->effective_cpus);
> - if (!cp->use_parent_ecpus)
> - cp->use_parent_ecpus = true;
> - } else if (cp->use_parent_ecpus) {
> - cp->use_parent_ecpus = false;
> - }
>
> if (remote)
> goto get_css;
> @@ -2452,8 +2436,7 @@ static void update_sibling_cpumasks(struct cpuset *parent, struct cpuset *cs,
> * Check all its siblings and call update_cpumasks_hier()
> * if their effective_cpus will need to be changed.
> *
> - * With the addition of effective_xcpus which is a subset of
> - * cpus_allowed. It is possible a change in parent's effective_cpus
> + * It is possible a change in parent's effective_cpus
> * due to a change in a child partition's effective_xcpus will impact
> * its siblings even if they do not inherit parent's effective_cpus
> * directly.
> @@ -2467,8 +2450,7 @@ static void update_sibling_cpumasks(struct cpuset *parent, struct cpuset *cs,
> cpuset_for_each_child(sibling, pos_css, parent) {
> if (sibling == cs)
> continue;
> - if (!sibling->use_parent_ecpus &&
> - !is_partition_valid(sibling)) {
> + if (!is_partition_valid(sibling)) {
> compute_effective_cpumask(tmp->new_cpus, sibling,
> parent);
> if (cpumask_equal(tmp->new_cpus, sibling->effective_cpus))
> @@ -4128,7 +4110,6 @@ static int cpuset_css_online(struct cgroup_subsys_state *css)
> if (is_in_v2_mode()) {
> cpumask_copy(cs->effective_cpus, parent->effective_cpus);
> cs->effective_mems = parent->effective_mems;
> - cs->use_parent_ecpus = true;
> }
> spin_unlock_irq(&callback_lock);
>
> @@ -4194,9 +4175,6 @@ static void cpuset_css_offline(struct cgroup_subsys_state *css)
> is_sched_load_balance(cs))
> update_flag(CS_SCHED_LOAD_BALANCE, cs, 0);
>
> - if (cs->use_parent_ecpus)
> - cs->use_parent_ecpus = false;
> -
> cpuset_dec();
> clear_bit(CS_ONLINE, &cs->flags);
>
LGTM
Reviewed-by: Waiman Long <longman@redhat.com>
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