Re: GSoC Make Dragonfly NUMA-aware

["Edward O'Callaghan" <eocallaghan@xxxxxxxxxxxx>]

Hi Jeff,

I already started on this however I would be happy to hand it over and
mentor you if you wish.
Basically its a three step process,

a.) Your need to make sure the DF ACPI subsystem has all the hooks you
need to get the required information from the BIOS. (This can be done
as you go really..)
b.) There are two bits of information your need from the BIOS, SLIT
(System Locality Information Table) and SRAT (Static
Resource Affinity Table). This is just a matter of making a link list
with each node filled with information parsed from these two 'tables'.
c.) This is by far the hardest part to get right out of the whole job;
Your need to make a NUMA scheduler and make the kernel use the pared
NUMA information in a useful way.

 - The SLIT table is actually a matrix with "distances" between nodes,
this should basically be proportional to the memory access latency
ratios.
 - SRAT stores the topology "who they belongs to" information for all
the processors and memory, describing the physical locations of the
processors and memory in the system. It also describes what memory is
hot-pluggable, and what is not. Note that some nodes may not
necessarily have a corresponding processor.

I have completed my research on doing the ACPI side (part 'a' and 'b')
of things for the most part and believe I have a set of API's for
that, which are basically similar to NetBSD's. I have started to
implement a few basic functions and written a few draft struct types.
At the end of this week I shall have more time and thus more
details/code for you.

Hope this is ok as a intro? Let me know if you need to know anything
in particular and any or all your questions.

Cheers,
Edward O'Callaghan.

On 31 March 2010 09:31, Jeff Leep <sleepjeff@gmail.com> wrote:
> Hello, my name is Jeff Leep.
>
>  I'm a third year computer science major at Grinnell College, and I'm
> interested in the "Make Dragonfly NUMA-aware" Google Summer of Code project
> for DragonFlyBSD. I recently completed a basic class on computer
> organization and architecture. I was wondering if  this project would be
> feasible for me and if you could give me more information on the project.
>
> Thanks a lot,
>
> -Jeff
>



-- 
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Edward O'Callaghan
http://www.auroraux.org/
eocallaghan at auroraux dot org
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