Messages in this thread | | | Date | Wed, 16 Jan 2002 09:42:26 -0800 | From | William Lee Irwin III <> | Subject | Re: hashed waitqueues |
| |
On Wed, Jan 16, 2002 at 02:21:41PM +0000, Jamie Lokier wrote: > Looking up "good hash function" on Google leads to these notable pages: [various URL's] > The last one is interesting because it mentions the golden prime > multiplier function, and suggests good non-multipler functions instead. > (Justification: the multiplier function doesn't distribute bits evenly).
Excellent! I can always use more of these to test.
It seems odd that they don't like Fibonacci hashing, it appears to pass various chi^2 tests on bucket distribution. And operator-sparse Fibonacci hashing primes appear to pass it as well, at least once 10 terms of the continued fraction match (operator-sparse Fibonacci hashing primes means that the multiplication can be done with shifts and adds or subtracts).
Regardless, various arches want non-multiplicative hash functions and they'll be getting them. These hash functions will certainly prove useful in getting a broader base to test against. I don't care to have a "pet" hash function, only one that is good as possible.
Thanks, Bill - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |