aboutsummaryrefslogtreecommitdiff
path: root/kernel/sched/fair.c
diff options
context:
space:
mode:
authorChengming Zhou <zhouchengming@bytedance.com>2022-08-18 20:48:03 +0800
committerPeter Zijlstra <peterz@infradead.org>2022-08-23 11:01:19 +0200
commitdf16b71c686cb096774e30153c9ce6756450796c (patch)
tree91b3b04f50be7489b5d8c0ccca0abf4a3e79ced9 /kernel/sched/fair.c
parent7e2edaf61814fb6aa363989d718950c023b882d4 (diff)
sched/fair: Allow changing cgroup of new forked task
commit 7dc603c9028e ("sched/fair: Fix PELT integrity for new tasks") introduce a TASK_NEW state and an unnessary limitation that would fail when changing cgroup of new forked task. Because at that time, we can't handle task_change_group_fair() for new forked fair task which hasn't been woken up by wake_up_new_task(), which will cause detach on an unattached task sched_avg problem. This patch delete this unnessary limitation by adding check before do detach or attach in task_change_group_fair(). So cpu_cgrp_subsys.can_attach() has nothing to do for fair tasks, only define it in #ifdef CONFIG_RT_GROUP_SCHED. Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20220818124805.601-8-zhouchengming@bytedance.com
Diffstat (limited to 'kernel/sched/fair.c')
-rw-r--r--kernel/sched/fair.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index e92bc053aff6..fd1aa4c92b2d 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -11676,6 +11676,13 @@ void init_cfs_rq(struct cfs_rq *cfs_rq)
#ifdef CONFIG_FAIR_GROUP_SCHED
static void task_change_group_fair(struct task_struct *p)
{
+ /*
+ * We couldn't detach or attach a forked task which
+ * hasn't been woken up by wake_up_new_task().
+ */
+ if (READ_ONCE(p->__state) == TASK_NEW)
+ return;
+
detach_task_cfs_rq(p);
#ifdef CONFIG_SMP