On 10/21, Honglei Wang wrote:
>
> @@ -230,6 +230,15 @@ void cgroup_freezer_migrate_task(struct task_struct *task,
> + /*
> + * It's not necessary to do changes if both of the src and dst cgroups
> + * are not freeze and task is not frozen.
> + */
> + if (!test_bit(CGRP_FREEZE, &src->flags) &&
> + !test_bit(CGRP_FREEZE, &dst->flags) &&
> + !task->frozen)
> + return;
> +
If we want to optimize cgroup_freezer_migrate_task()... I am sure I missed
something, but can't we do better ?
If a frozen task enters or leaves cgrp, this should never change the state
of FROZEN bit?
Oleg.
--- x/kernel/cgroup/freezer.c
+++ x/kernel/cgroup/freezer.c
@@ -238,14 +238,14 @@ void cgroup_freezer_migrate_task(struct
if (task->frozen) {
cgroup_inc_frozen_cnt(dst);
cgroup_dec_frozen_cnt(src);
+ } else {
+ if (test_bit(CGRP_FREEZE, &src->flags))
+ cgroup_update_frozen(src);
+ if (test_bit(CGRP_FREEZE, &dst->flags)) {
+ cgroup_update_frozen(dst);
+ cgroup_freeze_task(task, true);
+ }
}
- cgroup_update_frozen(dst);
- cgroup_update_frozen(src);
-
- /*
- * Force the task to the desired state.
- */
- cgroup_freeze_task(task, test_bit(CGRP_FREEZE, &dst->flags));
}
void cgroup_freeze(struct cgroup *cgrp, bool freeze)
