Re: [Gems-users] Message size, link weight, bash code

["Niket Agarwal (niketa@xxxxxxxxxxxxx)" <niketa@xxxxxxxxxxxxx>]

Link weight is defaulted to "link latency" if otherwise specified and is
then used to calculate the shortest path from one point to the other in
the network. This is used for routing.

All this works fine if you use infinite buffering. For finite buffering
though, the routing has to be restricted to dimension ordered e-cube and
hence the link-weights have to be accordingly specified in the network
topology file.

- Niket


>     1. In Throttle.C, the function network_message_to_size() uses a constant
>     MESSAGE_SIZE_MULTIPLIER whose value is 1000 to multiply with the message
>     size. Why do we need this value? I think the message sizes in GEMS should be
>     8B for control message and 64+8B for data message. But with this value, the
>     message sizes are 1000 times larger. Is that correct?
>
>        
>
> The bandwidth unit in the simulator is 1/1000 of a byte. This was for
> smooth graduation of curves for the BASH paper
>
>     2. What dese the link weight mean in network code? Basically we have three
>     properties in a link: latency, bandwidth and weight. I noticed by default
>     the link weight was set to the same as latency, but it has been used when
>     calculating the routing route. So I am a little confused about the weight.
>
>        
>
> i believe the link_weight is for E_cube routing when FINITE_BUFFERING
> is enabled. I'm not positive though.
>
>     3. In the wakeup function of Throttle.C, there is a piece of Bash code. I am
>     wondering what it's used for.
>
>        
>
> BASH-- Bandwidth Adaptive Snooping, Martin et al.
>
> http://www.cs.wisc.edu/multifacet/papers/hpca02_bash.pdf
>
>