Firstly offline cpu1:
# echo 0-1 > cpuset.cpus
# echo 0 > /sys/devices/system/cpu/cpu1/online
# cat cpuset.cpus
0-1
# cat cpuset.effective_cpus
0
Then online it:
# echo 1 > /sys/devices/system/cpu/cpu1/online
# cat cpuset.cpus
0-1
# cat cpuset.effective_cpus
0-1
And cpuset will bring it back to the effective mask.
This is a behavior change for sane_behavior.
Signed-off-by: Li Zefan <lizefan@xxxxxxxxxx>
---
kernel/cpuset.c | 140 +++++++++++++++++++++++++++++++-------------------------
1 file changed, 77 insertions(+), 63 deletions(-)
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index c3a02a9..20fc109 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -2134,6 +2134,77 @@ static void remove_tasks_in_empty_cpuset(struct cpuset *cs)
}
}
+static void hotplug_update_tasks_insane(struct cpuset *cs,
+ struct cpumask *off_cpus,
+ nodemask_t *off_mems)
+{
+ bool is_empty;
+
+ cpumask_andnot(off_cpus, cs->real_cpus_allowed,
+ top_cpuset.real_cpus_allowed);
+ nodes_andnot(*off_mems, cs->real_mems_allowed,
+ top_cpuset.real_mems_allowed);
+
+ mutex_lock(&callback_mutex);
+ cpumask_andnot(cs->cpus_allowed, cs->cpus_allowed, off_cpus);
+ cpumask_andnot(cs->real_cpus_allowed, cs->real_cpus_allowed, off_cpus);
+ nodes_andnot(cs->mems_allowed, cs->mems_allowed, *off_mems);
+ nodes_andnot(cs->real_mems_allowed, cs->real_mems_allowed, *off_mems);
+ mutex_unlock(&callback_mutex);
+
+ /*
+ * Don't call update_tasks_cpumask() if the cpuset becomes empty,
+ * as the tasks will be migrated to an ancestor.
+ */
+ if (!cpumask_empty(off_cpus) && !cpumask_empty(cs->cpus_allowed))
+ update_tasks_cpumask(cs, NULL);
+
+ if (!nodes_empty(*off_mems) && !cpumask_empty(cs->cpus_allowed))
+ update_tasks_nodemask(cs, NULL);
+
+ is_empty = cpumask_empty(cs->cpus_allowed) ||
+ nodes_empty(cs->mems_allowed);
+
+ mutex_unlock(&cpuset_mutex);
+ /*
+ * Move tasks to the nearest ancestor with execution resources,
+ * This is full cgroup operation which will also call back into
+ * cpuset. Should be don outside any lock.
+ */
+ if (is_empty)
+ remove_tasks_in_empty_cpuset(cs);
+ mutex_lock(&cpuset_mutex);
+}
+
+static void hotplug_update_tasks_sane(struct cpuset *cs,
+ struct cpumask *new_cpus,
+ nodemask_t *new_mems)
+{
+ struct cpuset *parent = parent_cs(cs);
+ bool update_cpus, update_mems;
+
+ cpumask_and(new_cpus, cs->cpus_allowed, parent->real_cpus_allowed);
+ if (cpumask_empty(new_cpus))
+ cpumask_copy(new_cpus, parent->real_cpus_allowed);
+
+ nodes_and(*new_mems, cs->mems_allowed, parent->real_mems_allowed);
+ if (nodes_empty(*new_mems))
+ *new_mems = parent->real_mems_allowed;
+
+ update_cpus = !cpumask_equal(cs->real_cpus_allowed, new_cpus);
+ update_mems = !nodes_equal(cs->real_mems_allowed, new_mems);
+
+ mutex_lock(&callback_mutex);
+ cpumask_copy(cs->real_cpus_allowed, new_cpus);
+ cs->real_mems_allowed = *new_mems;
+ mutex_unlock(&callback_mutex);
+
+ if (update_cpus)
+ update_tasks_cpumask(cs, NULL);
+ if (update_mems)
+ update_tasks_nodemask(cs, NULL);
+}
+
/**
* cpuset_hotplug_update_tasks - update tasks in a cpuset for hotunplug
* @cs: cpuset in interest
@@ -2144,9 +2215,8 @@ static void remove_tasks_in_empty_cpuset(struct cpuset *cs)
*/
static void cpuset_hotplug_update_tasks(struct cpuset *cs)
{
- static cpumask_t off_cpus;
- static nodemask_t off_mems;
- bool is_empty;
+ static cpumask_t tmp_cpus;
+ static nodemask_t tmp_mems;
bool sane = cgroup_sane_behavior(cs->css.cgroup);
retry:
@@ -2163,67 +2233,11 @@ retry:
goto retry;
}
- cpumask_andnot(&off_cpus, cs->real_cpus_allowed,
- top_cpuset.real_cpus_allowed);
- nodes_andnot(off_mems, cs->real_mems_allowed,
- top_cpuset.real_mems_allowed);
-
- mutex_lock(&callback_mutex);
- if (!sane)
- cpumask_andnot(cs->cpus_allowed, cs->cpus_allowed, &off_cpus);
-
- cpumask_andnot(cs->real_cpus_allowed, cs->real_cpus_allowed,
- &off_cpus);
- /* Inherite the effective mask of the parent, if it becomes empty */
- if (cpumask_empty(cs->real_cpus_allowed))
- cpumask_copy(cs->real_cpus_allowed,
- parent_cs(cs)->real_cpus_allowed);
- mutex_unlock(&callback_mutex);
-
- /*
- * If sane_behavior flag is set, we need to update tasks' cpumask
- * for empty cpuset to take on ancestor's cpumask. Otherwise, don't
- * call update_tasks_cpumask() if the cpuset becomes empty, as
- * the tasks in it will be migrated to an ancestor.
- */
- if ((sane && cpumask_empty(cs->cpus_allowed)) ||
- (!cpumask_empty(&off_cpus) && !cpumask_empty(cs->cpus_allowed)))
- update_tasks_cpumask(cs, NULL);
-
- mutex_lock(&callback_mutex);
- if (!sane)
- nodes_andnot(cs->mems_allowed, cs->mems_allowed, off_mems);
-
- nodes_andnot(cs->real_mems_allowed, cs->real_mems_allowed, off_mems);
- /* Inherite the effective mask of the parent, if it becomes empty */
- if (nodes_empty(cs->real_mems_allowed))
- cs->real_mems_allowed = parent_cs(cs)->real_mems_allowed;
- mutex_unlock(&callback_mutex);
-
- /*
- * If sane_behavior flag is set, we need to update tasks' nodemask
- * for empty cpuset to take on ancestor's nodemask. Otherwise, don't
- * call update_tasks_nodemask() if the cpuset becomes empty, as
- * the tasks in it will be migratd to an ancestor.
- */
- if ((sane && nodes_empty(cs->mems_allowed)) ||
- (!nodes_empty(off_mems) && !nodes_empty(cs->mems_allowed)))
- update_tasks_nodemask(cs, NULL);
-
- is_empty = cpumask_empty(cs->cpus_allowed) ||
- nodes_empty(cs->mems_allowed);
-
+ if (sane)
+ hotplug_update_tasks_sane(cs, &tmp_cpus, &tmp_mems);
+ else
+ hotplug_update_tasks_insane(cs, &tmp_cpus, &tmp_mems);
mutex_unlock(&cpuset_mutex);
-
- /*
- * If sane_behavior flag is set, we'll keep tasks in empty cpusets.
- *
- * Otherwise move tasks to the nearest ancestor with execution
- * resources. This is full cgroup operation which will
- * also call back into cpuset. Should be done outside any lock.
- */
- if (!sane && is_empty)
- remove_tasks_in_empty_cpuset(cs);
}
/**
--
1.8.0.2
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