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cpuset: Make generate_sched_domains() work with partition

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The generate_sched_domains() function is modified to make it work
correctly with the newly introduced subparts_cpus mask for scheduling
domains generation.

Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Waiman Long 2018-11-08 10:08:42 -05:00 committed by Tejun Heo
parent 4b842da276
commit 0ccea8feb9
1 changed files with 27 additions and 7 deletions
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34
kernel/cgroup/cpuset.c
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@ -769,13 +769,14 @@ static int generate_sched_domains(cpumask_var_t **domains,
int ndoms = 0; /* number of sched domains in result */
int nslot; /* next empty doms[] struct cpumask slot */
struct cgroup_subsys_state *pos_css;
bool root_load_balance = is_sched_load_balance(&top_cpuset);
doms = NULL;
dattr = NULL;
csa = NULL;
/* Special case for the 99% of systems with one, full, sched domain */
if (is_sched_load_balance(&top_cpuset)) {
if (root_load_balance && !top_cpuset.nr_subparts_cpus) {
ndoms = 1;
doms = alloc_sched_domains(ndoms);
if (!doms)
@ -798,6 +799,8 @@ static int generate_sched_domains(cpumask_var_t **domains,
csn = 0;
rcu_read_lock();
if (root_load_balance)
csa[csn++] = &top_cpuset;
cpuset_for_each_descendant_pre(cp, pos_css, &top_cpuset) {
if (cp == &top_cpuset)
continue;
@ -808,6 +811,9 @@ static int generate_sched_domains(cpumask_var_t **domains,
* parent's cpus, so just skip them, and then we call
* update_domain_attr_tree() to calc relax_domain_level of
* the corresponding sched domain.
*
* If root is load-balancing, we can skip @cp if it
* is a subset of the root's effective_cpus.
*/
if (!cpumask_empty(cp->cpus_allowed) &&
!(is_sched_load_balance(cp) &&
@ -815,11 +821,16 @@ static int generate_sched_domains(cpumask_var_t **domains,
housekeeping_cpumask(HK_FLAG_DOMAIN))))
continue;
if (root_load_balance &&
cpumask_subset(cp->cpus_allowed, top_cpuset.effective_cpus))
continue;
if (is_sched_load_balance(cp))
csa[csn++] = cp;
/* skip @cp's subtree */
pos_css = css_rightmost_descendant(pos_css);
/* skip @cp's subtree if not a partition root */
if (!is_partition_root(cp))
pos_css = css_rightmost_descendant(pos_css);
}
rcu_read_unlock();
@ -947,7 +958,12 @@ static void rebuild_sched_domains_locked(void)
* passing doms with offlined cpu to partition_sched_domains().
* Anyways, hotplug work item will rebuild sched domains.
*/
if (!cpumask_equal(top_cpuset.effective_cpus, cpu_active_mask))
if (!top_cpuset.nr_subparts_cpus &&
!cpumask_equal(top_cpuset.effective_cpus, cpu_active_mask))
goto out;
if (top_cpuset.nr_subparts_cpus &&
!cpumask_subset(top_cpuset.effective_cpus, cpu_active_mask))
goto out;
/* Generate domain masks and attrs */
@ -1367,11 +1383,15 @@ static void update_cpumasks_hier(struct cpuset *cs, struct tmpmasks *tmp)
update_tasks_cpumask(cp);
/*
* If the effective cpumask of any non-empty cpuset is changed,
* we need to rebuild sched domains.
* On legacy hierarchy, if the effective cpumask of any non-
* empty cpuset is changed, we need to rebuild sched domains.
* On default hierarchy, the cpuset needs to be a partition
* root as well.
*/
if (!cpumask_empty(cp->cpus_allowed) &&
is_sched_load_balance(cp))
is_sched_load_balance(cp) &&
(!cgroup_subsys_on_dfl(cpuset_cgrp_subsys) ||
is_partition_root(cp)))
need_rebuild_sched_domains = true;
rcu_read_lock();