Re: [RFC][PATCH 00/15] sched: SCHED_DEADLINE v5

[Peter Zijlstra]

On Mon, 2012-05-28 at 11:06 +0200, Juri Lelli wrote:
>   o  The only "big problem" I fear is related to the current deadline
>      inheritance mechanism. As Steven pointed out during the last review,
>      a task could force more bandwidth than was allowed if:
> 
>         - it takes a futex;
>         - it is boosted while holding it;
>         - never releases the futex;
> 
>      and this is sadly achievable since, if boosted, a task inherits top
>      waiter parameters and the enforcement mechanism is temporarily
>      disabled for it. 

/me goes read patch 12 in detail..

Wouldn't it be possible to enforce pi_se (aka. pi_task)'s bandwidth in
the dl-boosts-dl case?

Since afaict that's the only case we need to worry about. If you can
spawn FIFO/RR tasks you already loose bandwidth caps etc..


--
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/