Re: [RFC v4 PATCH 2/7] sched: Bandwidth initialization for fair task groups

[Peter Zijlstra <peterz@infradead.org>]

On Tue, 2009-11-17 at 20:04 +0530, Bharata B Rao wrote:

> +++ b/kernel/sched.c
> @@ -237,6 +237,15 @@ static DEFINE_MUTEX(sched_domains_mutex);
>  
>  #include <linux/cgroup.h>
>  
> +#if defined(CONFIG_FAIR_GROUP_SCHED) && defined(CONFIG_CFS_HARD_LIMITS)
> +struct cfs_bandwidth {
> +	spinlock_t		cfs_runtime_lock;
> +	ktime_t			cfs_period;
> +	u64			cfs_runtime;
> +	struct hrtimer		cfs_period_timer;
> +};
> +#endif
> +
>  struct cfs_rq;
>  
>  static LIST_HEAD(task_groups);

So what's wrong with using struct rt_bandwidth, aside from the name?

> @@ -445,6 +457,19 @@ struct cfs_rq {
>  	unsigned long rq_weight;
>  #endif
>  #endif
> +#ifdef CONFIG_CFS_HARD_LIMITS
> +	/* set when the group is throttled  on this cpu */
> +	int cfs_throttled;
> +
> +	/* runtime currently consumed by the group on this rq */
> +	u64 cfs_time;
> +
> +	/* runtime available to the group on this rq */
> +	u64 cfs_runtime;
> +
> +	/* Protects the cfs runtime related fields of this cfs_rq */
> +	spinlock_t cfs_runtime_lock;
> +#endif
>  };

If you put these 4 in a new struct, say rq_bandwidth, and also use that
for rt_rq, then I bet you can write patch 6 with a lot less copy/paste
action.