Re: Is it better to set the freelist to a prime number ?

Thanks for the reference, which I've followed up. Suddenly it's all clear.

It makes no difference whether the value is prime or not. The significance appears I think when you use multiple free lists AND multiple freelist groups in a single instance.

In this case, the number of freelists and the number of freelist groups must be relatively prime (co-prime ?) or you don't make use of all the freelists in all the freelist blocks.

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Andrew Mobbs wrote in message <9uo*Yp3tp_at_news.chiark.greenend.org.uk>...


>Connor McDonald  <connor_mcdonald_at_yahoo.com> wrote:

>>

>>Do we (anyone?) have any insider info on the hash algorithm used for

>>freelist mapping?  Is it plain ol' modulo - in which case, the use of

>>prime number would be suitable, but there's also endless (non-modulo)

>>hashing algoriths out there that would not have such a requirement

>

>Metalink Doc Id 1029850.6

>

>Basically, yes, it's just PID mod number of freelists (or groups).

>

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>Andrew Mobbs - http://www.chiark.greenend.org.uk/~andrewm/