Re: [rfc][patch] dynamic resizing dentry hash using RCU

From: Michael K. Edwards
Date: Fri Feb 23 2007 - 20:31:53 EST

On 2/23/07, Zach Brown <zab@xxxxxxxxx> wrote:
I'd love to see a generic implementation of RCU hashing that
subsystems can then take advantage of. It's long been on the fun
side of my todo list. The side I never get to :/.

There's an active thread on netdev about implementing an RCU hash.
I'd suggest a 2-left (or possibly even k-left) hash for statistical
reasons discussed briefly there, and in greater depth in a paper by
Michael Mitzenmacher at
Despite his paper's emphasis on hardware parallelism, there's a bigger
win associated with Poisson statistics and decreasing occupation
fraction (and therefore collision probability) in successive hashes.

- Michael
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