From 3c2acae88844e7423a50b5cbe0a2c9d430fcd20c Mon Sep 17 00:00:00 2001 From: Chen Ridong Date: Tue, 20 Aug 2024 03:01:26 +0000 Subject: [PATCH] cgroup/cpuset: remove use_parent_ecpus of cpuset 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 Reviewed-by: Waiman Long Signed-off-by: Tejun Heo --- 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 92e79ddc8188..7db55eed63cf 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);