Re: [PATCH 6/6] sched: disabled rt-bandwidth by default

From: Ingo Molnar
Date: Thu Aug 28 2008 - 12:26:23 EST



* Max Krasnyansky <maxk@xxxxxxxxxxxx> wrote:

> Andi Kleen wrote:
>> On Thu, Aug 28, 2008 at 01:19:13PM +0200, Peter Zijlstra wrote:
>>> On Thu, 2008-08-28 at 13:09 +0200, Andi Kleen wrote:
>>>>> Even if the system has multiple CPUs, and even if just a single CPU is
>>>>> fully utilized by an RT task, without the rt-limit the system will still
>>>>> lock up in practice due to various other factors: workqueues and tasks
>>>>> being 'stuck' on CPUs that host an RT hog.
>>>> The load balancer will not notice that a particular CPU is busy
>>>> with real time tasks?
>>> Not currently, working on that though.
>>
>> I wonder if it would make sense to break affinities in extreme case?
>> With that even the workqueues would work again.
>
> Please lets not break affinity :).

correct, breaking affinity is a rather stupid idea.

Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/