Re: Circular Convolution scheduler

Nick Piggin
2003-10-14T10:22:12Z

Jamie Lokier wrote:

>Piet Delaney wrote:
>
>>circular convolution is used with the Fast Fourier Transform.
>>The frequency data goes from -N/2 ...0 ,,,, +N/2,
>>multiplying in the frequency domain is the same as
>>convolving in the time or space domain. The result of multiplying
>>a time series by say a filter is the same as convolving it
>>with the FFT of the filter. Both domains wrap around with the
>>FFT, so the normal convolution associated with the Fourier
>>transform is replace with the circular convolution.
>>
>>Many prediction algorithms are based on digital signal processing.
>>The Kalman filter for example was used by Harvey for forecasting
>>financial markets. The kernel likely has lots of time series that
>>could be used for system identification for predicting how to best
>>use system resources.
>>
>
>Ok, but what is "circular convolution scheduling"?
>
>

I don't know anything about it, but I don't see what exactly you'd be
trying to predict: the kernel's scheduler _dictates_ scheduling behaviour,
obviously. Also, "best use of system resources" wrt scheduling is a big
ask considering there isn't one ideal scheduling pattern for all but the
most trivial loads, even on a single processor computer (fairness, latency,
priority, thoughput, etc). Its difficult to even say one pattern is better
than another.