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From: Tim Prins (tprins_at_[hidden])
Date: 2007-05-29 10:56:03

I think both patches should be put in immediately. I have done some
simple testing, and with 128 nodes of odin, with 1024 processes
running mpi hello, these decrease our running time from about 14.2
seconds to 10.9 seconds. This is a significant decrease, and as the
scale increases there should be increasing benefit.

I'd be happy to commit these changes if no one objects.


On May 24, 2007, at 8:39 AM, Ralph H Castain wrote:

> Thanks - I'll take a look at this (and the prior ones!) in the next
> couple
> of weeks when time permits and get back to you.
> Ralph
> On 5/23/07 1:11 PM, "George Bosilca" <bosilca_at_[hidden]> wrote:
>> Attached is another patch to the ORTE layer, more specifically the
>> replica. The idea is to decrease the number of strcmp by using a
>> small hash function before doing the strcmp. The hask key for each
>> registry entry is computed when it is added to the registry. When
>> we're doing a query, instead of comparing the 2 strings we first
>> check if the hash key match, and if they do match then we compare the
>> 2 strings in order to make sure we eliminate collisions from our
>> answers.
>> There is some benefit in terms of performance. It's hardly visible
>> for few processes, but it start showing up when the number of
>> processes increase. In fact the number of strcmp in the trace file
>> drastically decrease. The main reason it works well, is because most
>> of the keys start with basically the same chars (such as orte-
>> blahblah) which transform the strcmp on a loop over few chars.
>> Ralph, please consider it for inclusion on the ORTE layer.
>> Thanks,
>> george.
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