Re: How how latent should non-preemptive scheduling be?

[Sitsofe Wheeler]

Ingo Molnar wrote:
> well, since they went away after you enabled CONFIG_PREEMPT=y, they are 
> definitely in-kernel latencies, not any external SMM latencies.
>
> I.e. they are inherently fixable. Could you enable:
>
>   CONFIG_DYNAMIC_FTRACE=y
>   CONFIG_FTRACE_MCOUNT_RECORD=y
>
> that should make the traces a lot more verbose - every kernel function 
> executed in the latency path will be logged. That way we'll be able to 
> say which one takes that long.

I do not appear to have the CONFIG_FTRACE_MCOUNT_RECORD option in 
2.6.27rc7. Is it an option that is only in -tip ?

--
Sitsofe | http://sucs.org/~sits/
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