On 2024/7/24 10:16, Waiman Long wrote:
On 7/23/24 21:08, Chen Ridong wrote:
The child_ecpus_count variable was previously used to update
sibling cpumask when parent's effective_cpus is updated. However, it
became
obsolete after commit e2ffe502ba45 ("cgroup/cpuset: Add
cpuset.cpus.exclusive for v2"). It should be removed.
Thanks for finding that.
Signed-off-by: Chen Ridong <chenridong@xxxxxxxxxx>
---
kernel/cgroup/cpuset.c | 13 -------------
1 file changed, 13 deletions(-)
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 40ec4abaf440..146bf9258db2 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -188,10 +188,8 @@ struct cpuset {
/*
* Default hierarchy only:
* use_parent_ecpus - set if using parent's effective_cpus
- * child_ecpus_count - # of children with use_parent_ecpus set
*/
int use_parent_ecpus;
- int child_ecpus_count;
/*
* number of SCHED_DEADLINE tasks attached to this cpuset, so
that we
@@ -1512,7 +1510,6 @@ static void reset_partition_data(struct cpuset *cs)
if (!cpumask_and(cs->effective_cpus,
parent->effective_cpus, cs->cpus_allowed)) {
cs->use_parent_ecpus = true;
- parent->child_ecpus_count++;
cpumask_copy(cs->effective_cpus, parent->effective_cpus);
}
}
@@ -1689,10 +1686,7 @@ static int remote_partition_enable(struct
cpuset *cs, int new_prs,
isolcpus_updated = partition_xcpus_add(new_prs, NULL,
tmp->new_cpus);
list_add(&cs->remote_sibling, &remote_children);
if (cs->use_parent_ecpus) {
- struct cpuset *parent = parent_cs(cs);
-
cs->use_parent_ecpus = false;
- parent->child_ecpus_count--;
}
You can also remove { } or just set use_parent_ecpus to false.
spin_unlock_irq(&callback_lock);
update_unbound_workqueue_cpumask(isolcpus_updated);
@@ -2320,12 +2314,9 @@ static void update_cpumasks_hier(struct cpuset
*cs, struct tmpmasks *tmp,
cpumask_copy(tmp->new_cpus, parent->effective_cpus);
if (!cp->use_parent_ecpus) {
cp->use_parent_ecpus = true;
- parent->child_ecpus_count++;
}
Just set it to true.
} else if (cp->use_parent_ecpus) {
cp->use_parent_ecpus = false;
- WARN_ON_ONCE(!parent->child_ecpus_count);
- parent->child_ecpus_count--;
}
Remove {} or set it to false.
if (remote)
@@ -4139,7 +4130,6 @@ static int cpuset_css_online(struct
cgroup_subsys_state *css)
cpumask_copy(cs->effective_cpus, parent->effective_cpus);
cs->effective_mems = parent->effective_mems;
cs->use_parent_ecpus = true;
- parent->child_ecpus_count++;
}
spin_unlock_irq(&callback_lock);
@@ -4206,10 +4196,7 @@ static void cpuset_css_offline(struct
cgroup_subsys_state *css)
update_flag(CS_SCHED_LOAD_BALANCE, cs, 0);
if (cs->use_parent_ecpus) {
- struct cpuset *parent = parent_cs(cs);
-
cs->use_parent_ecpus = false;
- parent->child_ecpus_count--;
}
Just set it to false.
Cheers,
Longman
Thank you, Longman, I will do that.
I am considering the necessity of use_parent_ecpus. Currently, the
use_parent_ecpus variable is only utilized within the
update_sibling_cpumasks function. This implies that if a cpuset is not
configured to use its parent's effective_cpus, it might not need to
invoke update_cpumasks_hier. However, the invocation of
update_cpumasks_hier may not be necessary for a cpuset, regardless of
whether it uses its parent's effective_cpus, if there is no change in
the cpuset's effective_cpus.
Is use_parent_ecpus still relevant?
Or, do I miss something?
Thanks
Ridong
