[RFC PATCH 4/4] arm64:numa: adding numa support for arm64 platforms.

[Ganapatrao Kulkarni]

On Mon, Oct 20, 2014 at 8:00 PM, Steve Capper <steve.capper at linaro.org> wrote:
> On Mon, Oct 20, 2014 at 03:25:56PM +0100, Steve Capper wrote:
>> On Fri, Oct 17, 2014 at 10:49:56PM +0530, Ganapatrao Kulkarni wrote:
>
> [...]
>
>>          /*Proximity Distance matrix for 4Node system
>> >                        <from-node to-node distance>
>> >         */
>> >          node-matrix=    <0 0 10>,
>> >                                <0 1 20>,
>> >                                <0 2 30>,
>> >                                <0 3 10>,
>> >                                <1 0 20>,
>> >                                 <1 1 10>,
>> >                                <1 2 30>,
>> >                               <1 3 10>,
>> >                               <2 0 30>,
>> >                               <2 1 20>,
>> >                               <2 2 10>,
>> >                              <2 3 10>,
>> >                             <3 0 10>,
>> >                             <3 1 20>,
>> >                             <3 2 30>,
>> >                             <3 3 10>,
>> >  }
>>
>> Hi Ganapat,
>> The above caught my attention.
>>
>> For a 4-node system do we not need 16 distances; the implication of that
>> would be that the distance between node A-B could be different from the
>> distance between B-A? Also the distance from a node to itself could be
>> safely assumed to be zero?
>>
>> I think we should have a symmetric matrix with zero-diagonals so strictly
>> only seven values would need specifying for a 4-node system.
Thanks Stave for the comments.
I too thought initially to take the assumption like
distance B-A is same as A-B and A-A is always defined to LOCAL.
However this example is an ideal case which will define all 16
distances for 4 node system.
In actual DT, we can skip to provide A-A and B-A, In kernel
implementation we will use these common/generic assumptions
to derive missing distances.
>
> s/seven/six/
>
> I really need to learn how to count.... :-/
>
>>
>> Cheers,
>> --
>> Steve
thanks
Ganapat