Messages in this thread | | | Date | Thu, 18 Aug 2022 18:48:39 +0800 | Subject | Re: [PATCH v5 7/9] sched/fair: allow changing cgroup of new forked task | From | Chengming Zhou <> |
| |
On 2022/8/18 18:36, Peter Zijlstra wrote: > On Thu, Aug 18, 2022 at 11:43:41AM +0800, Chengming Zhou wrote: > >> diff --git a/kernel/sched/core.c b/kernel/sched/core.c >> index 8e3f1c3f0b2c..157f7461a08a 100644 >> --- a/kernel/sched/core.c >> +++ b/kernel/sched/core.c >> @@ -4550,11 +4550,11 @@ int sched_fork(unsigned long clone_flags, struct task_struct *p) >> { >> __sched_fork(clone_flags, p); >> /* >> - * We mark the process as NEW here. This guarantees that >> + * We mark the process as running here. This guarantees that >> * nobody will actually run it, and a signal or other external >> * event cannot wake it up and insert it on the runqueue either. >> */ >> - p->__state = TASK_NEW; >> + p->__state = TASK_RUNNING; >> >> /* >> * Make sure we do not leak PI boosting priority to the child. >> @@ -4672,7 +4672,6 @@ void wake_up_new_task(struct task_struct *p) >> struct rq *rq; >> >> raw_spin_lock_irqsave(&p->pi_lock, rf.flags); >> - WRITE_ONCE(p->__state, TASK_RUNNING); >> #ifdef CONFIG_SMP >> /* >> * Fork balancing, do it here and not earlier because: >> @@ -10290,36 +10289,19 @@ static void cpu_cgroup_css_free(struct cgroup_subsys_state *css) >> sched_unregister_group(tg); >> } > >> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c >> index eba8a64f905a..e0d34ecdabae 100644 >> --- a/kernel/sched/fair.c >> +++ b/kernel/sched/fair.c >> @@ -11840,6 +11840,13 @@ 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 (!p->on_rq && !p->se.sum_exec_runtime) >> + return; >> + >> detach_task_cfs_rq(p); > > Wouldn't that be much clearer when expressed in TASK_NEW ?
Ah, I was stupid, will change to use TASK_NEW.
Thanks for your suggestion!
| |