Re: [PATCH v7 10/16] dlm: use new hashtable implementation

David Teigland
2012-10-29T16:24:46Z

On Mon, Oct 29, 2012 at 12:07:10PM -0400, Mathieu Desnoyers wrote:
> I'm fine with turning a direct + modulo mapping into a dispersed hash as
> long as there are no underlying assumptions about sequentiality of value
> accesses.
>
> If the access pattern would happen to be typically sequential, then
> adding dispersion could hurt performances significantly, turning a
> frequent L1 access into a L2 access for instance.

> All I'm asking is: have you made sure that this hash table is not
> deliberately kept sequential (without dispersion) to accelerate specific
> access patterns ? This should at least be documented in the changelog.

It was not intentional. I don't expect any benefit would be lost by
making it non-sequential.