Re: [linux-audio-dev] Re: [announce] [patch] Voluntary KernelPreemption Patch

From: Andrew Morton
Date: Thu Sep 02 2004 - 17:32:07 EST


Andrea Arcangeli <andrea@xxxxxxx> wrote:
>
> if you're scared that there are too many cond_resched (I'm not scared
> and people should enable them anyways if they make a difference, they
> still should be less than the number of spin_unlocks with preempt
> enabled), then you should add a cond_resched_costly and add a config
> option that turns it off.

None of these approaches improves worst-case latency at all on SMP. If
we're not going to address the SMP problem we could just make it UP-only,
in which case increased locking costs are a non-issue.

I'd prefer that we find a solution for SMP too though.
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