From: Waiman Long <longman@redhat.com>
To: Tejun Heo <tj@kernel.org>, Li Zefan <lizefan@huawei.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>
Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-doc@vger.kernel.org, kernel-team@fb.com, pjt@google.com,
luto@amacapital.net, Mike Galbraith <efault@gmx.de>,
torvalds@linux-foundation.org, Roman Gushchin <guro@fb.com>,
Juri Lelli <juri.lelli@redhat.com>,
Patrick Bellasi <patrick.bellasi@arm.com>,
Waiman Long <longman@redhat.com>
Subject: [PATCH v13 08/11] cpuset: Make generate_sched_domains() work with partition
Date: Fri, 12 Oct 2018 13:55:48 -0400 [thread overview]
Message-ID: <1539366951-8498-9-git-send-email-longman@redhat.com> (raw)
In-Reply-To: <1539366951-8498-1-git-send-email-longman@redhat.com>
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>
---
kernel/cgroup/cpuset.c | 34 +++++++++++++++++++++++++++-------
1 file changed, 27 insertions(+), 7 deletions(-)
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 578e6ae..c52074e 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -763,13 +763,14 @@ 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)
@@ -792,6 +793,8 @@ 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;
@@ -802,6 +805,9 @@ 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) &&
@@ -809,11 +815,16 @@ 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();
@@ -941,7 +952,12 @@ 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 */
@@ -1356,11 +1372,15 @@ 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();
--
1.8.3.1
next prev parent reply other threads:[~2018-10-12 17:56 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-12 17:55 [PATCH v13 00/11] cpuset: Enable cpuset controller in default hierarchy Waiman Long
2018-10-12 17:55 ` [PATCH v13 01/11] " Waiman Long
2018-10-15 18:31 ` Tom Hromatka
2018-10-15 18:41 ` Waiman Long
2018-10-15 19:10 ` Tom Hromatka
2018-10-12 17:55 ` [PATCH v13 02/11] cpuset: Define data structures to support scheduling partition Waiman Long
2018-10-12 17:55 ` [PATCH v13 03/11] cpuset: Simply allocation and freeing of cpumasks Waiman Long
2018-10-15 18:35 ` Tom Hromatka
2018-10-15 18:43 ` Waiman Long
2018-10-12 17:55 ` [PATCH v13 04/11] cpuset: Add new v2 cpuset.sched.partition flag Waiman Long
2018-10-13 14:10 ` kbuild test robot
2018-10-12 17:55 ` [PATCH v13 05/11] cpuset: Add an error state to cpuset.sched.partition Waiman Long
2018-10-12 17:55 ` [PATCH v13 06/11] cpuset: Track cpusets that use parent's effective_cpus Waiman Long
2018-10-12 17:55 ` [PATCH v13 07/11] cpuset: Make CPU hotplug work with partition Waiman Long
2018-10-12 17:55 ` Waiman Long [this message]
2018-10-12 17:55 ` [PATCH v13 09/11] cpuset: Expose cpus.effective and mems.effective on cgroup v2 root Waiman Long
2018-10-12 17:55 ` [PATCH v13 10/11] cpuset: Add documentation about the new "cpuset.sched.partition" flag Waiman Long
2018-10-12 17:55 ` [PATCH v13 11/11] cpuset: Expose cpuset.cpus.subpartitions with cgroup_debug Waiman Long
2018-10-15 16:35 ` [PATCH v13 00/11] cpuset: Enable cpuset controller in default hierarchy Tejun Heo
2018-10-15 17:04 ` Waiman Long
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