# Re: \[PATCH, v7\] cgroups: introduce timer slack controller

- From: Thomas Gleixner \<hidden\>
- Date: 2011-03-03 07:35:52 
- List: linux-api
- Page: https://ratatoskr.run/linux-api/2011/03/3685168
- Thread: https://ratatoskr.run/linux-api/2011/03/3684763/t.md

```text
On Thu, 3 Mar 2011, Li Zefan wrote:

> >> +unsigned long get_task_timer_slack(struct task_struct *tsk)
> >> +{
> >> +	struct cgroup_subsys_state *css;
> >> +	struct tslack_cgroup *tslack_cgroup;
> >> +	unsigned long ret;
> >> +
> >> +	rcu_read_lock();
> > 
> > Did you just remove the odd comment or actually figure out why you
> > need rcu_read_lock() here ?
> > 
> 
> It's necessary to protect against task exiting or task moving between cgroups.

I know, though after the last review I wanted to make sure, that the
author understands it as well and not just removed the odd comment
just because I ranted about it :)

Thanks,

	tglx
```