hotplug cpu move tasks in empty cpusets - refinements
- Narrow the scope of callback_mutex in scan_for_empty_cpusets().
- Avoid rewriting the cpus, mems of cpusets except when it is likely that
we'll be changing them.
- Have remove_tasks_in_empty_cpuset() also check for empty mems.
Signed-off-by: Paul Jackson <pj@sgi.com>
Acked-by: Cliff Wickman <cpw@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 6868c1e..67b2bfe 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1709,7 +1709,8 @@
* has online cpus, so can't be empty).
*/
parent = cs->parent;
- while (cpus_empty(parent->cpus_allowed))
+ while (cpus_empty(parent->cpus_allowed) ||
+ nodes_empty(parent->mems_allowed))
parent = parent->parent;
move_member_tasks_to_cpuset(cs, parent);
@@ -1741,7 +1742,6 @@
list_add_tail((struct list_head *)&root->stack_list, &queue);
- mutex_lock(&callback_mutex);
while (!list_empty(&queue)) {
cp = container_of(queue.next, struct cpuset, stack_list);
list_del(queue.next);
@@ -1750,19 +1750,24 @@
list_add_tail(&child->stack_list, &queue);
}
cont = cp->css.cgroup;
+
+ /* Continue past cpusets with all cpus, mems online */
+ if (cpus_subset(cp->cpus_allowed, cpu_online_map) &&
+ nodes_subset(cp->mems_allowed, node_states[N_HIGH_MEMORY]))
+ continue;
+
/* Remove offline cpus and mems from this cpuset. */
+ mutex_lock(&callback_mutex);
cpus_and(cp->cpus_allowed, cp->cpus_allowed, cpu_online_map);
nodes_and(cp->mems_allowed, cp->mems_allowed,
node_states[N_HIGH_MEMORY]);
+ mutex_unlock(&callback_mutex);
+
+ /* Move tasks from the empty cpuset to a parent */
if (cpus_empty(cp->cpus_allowed) ||
- nodes_empty(cp->mems_allowed)) {
- /* Move tasks from the empty cpuset to a parent */
- mutex_unlock(&callback_mutex);
+ nodes_empty(cp->mems_allowed))
remove_tasks_in_empty_cpuset(cp);
- mutex_lock(&callback_mutex);
- }
}
- mutex_unlock(&callback_mutex);
}
/*
