Re: [CFS Bandwidth Control v4 3/7] sched: throttle cfs_rq entities which exceed their local quota

[Balbir Singh <balbir@linux.vnet.ibm.com>]

* Paul Turner <pjt@google.com> [2011-02-15 19:18:34]:

> In account_cfs_rq_quota() (via update_curr()) we track consumption versus a
> cfs_rq's local quota and whether there is global quota available to continue
> enabling it in the event we run out.
> 
> This patch adds the required support for the latter case, throttling entities
> until quota is available to run.  Throttling dequeues the entity in question
> and sends a reschedule to the owning cpu so that it can be evicted.
> 
> The following restrictions apply to a throttled cfs_rq:
> - It is dequeued from sched_entity hierarchy and restricted from being
>   re-enqueued.  This means that new/waking children of this entity will be
>   queued up to it, but not past it.
> - It does not contribute to weight calculations in tg_shares_up
> - In the case that the cfs_rq of the cpu we are trying to pull from is throttled
>   it is  is ignored by the loadbalancer in __load_balance_fair() and
>   move_one_task_fair().
> 
> Signed-off-by: Paul Turner <pjt@google.com>
> Signed-off-by: Nikhil Rao <ncrao@google.com>
> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>


Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
 
-- 
	Three Cheers,
	Balbir