Re: [PATCH V6 1/1] Softirq:avoid large sched delay from the pending softirqs

[Qais Yousef]

On 09/11/20 12:14, John Dias wrote:
> I agree that the rt-softirq interaction patches are a gross hack (and I
> wrote the original versions, so it's my grossness). The problem is that
> even a 1ms delay in executing those low-latency audio threads is enough to
> cause obvious glitching in audio under very real circumstances, which is
> not an acceptable user experience -- and some softirq handlers run for >1ms
> on their own. (And 1ms is a high upper bound, not a median target.)

AFAIK professional audio apps have the toughest limit of sub 10ms. 120MHz
screens impose a stricter limit on display pipeline too to finish its frame in
8ms.

1ms is too short and approaches PREEMPT_RT realm.

Is it possible to expand on the use case here? What application requires this
constraint?

Thanks

--
Qais Yousef