Re: [Gems-users] Injection rate option doesn't work

[Niket Agarwal <niketa@xxxxxxxxxxxxx>]

A couple of things:

1. The injection rate parameter, as I used it, specifies the packet injection rate per-node. The curve in the paper uses flits/cycle. So you need to convert the packets to flits. Moreover, in the paper I tried to match the topology/traffic pattern, etc. used in previous papers. So, in some cases I have used multiple vnets and the topology was 7x7 and 8x8.

2. Secondly, looking at your stats it looks like you are just injecting traffic in one vnet and that is using only vc=0 to send traffic. This could be because the vnet is declared as "ordered." For network-only experiments, people usually assume unordered networks. You might want to change that.

Note that the garnet tester that I have provided is just for reference and you should feel free to modify it for your needs.

All the best.

-Niket

On 1/24/2010 11:37 PM, 신민정 wrote:

I checked that too, but the curve looks very linear.

By the way, I changed the injection_rate value in “Tester.C” file as

//injection_rate = .1;

injection_rate = RubyConfig::injectionRate();

 

where injectionRate() function returns g_TRAFFIC_INJECTION_RATE in “RubyConfig.h” file.

Is this right???

This is all I changed, but I think I did something wrong.

 

How did you get the curve in the paper using Garnet network tester???

 

I ran the tester on 4X4 mesh with MOESI CMP Directory protocol.

My running command is as follows.

           ./tester.exec -l 10000 -i 0.1

And output file shows

           Average Link Utilization :: 0.0897725 flits/cycle

-------------

Average VC Load [0] = 12.9272 flits/cycle

Average VC Load [1] = 0 flits/cycle

Average VC Load [2] = 0 flits/cycle

Average VC Load [3] = 0 flits/cycle

-------------

Total flits injected = 240090

Total flits recieved = 240090

Average network latency = 94.6688

Average queueing latency = 31032.1

Average latency = 31126.8

-------------

Total Link Power = 3.21034 W

Total Router Power = 8365.3 W

 

However, in the paper, average latency is under 50 when injection rate is 0.1.

I would appreciate your help.

 

Thanks.

 

Minjeong

 

From: Niket Agarwal [mailto:niketa@xxxxxxxxxxxxx]
Sent: Monday, January 25, 2010 1:46 AM
To: Minjeong Shin
Cc: Gems Users
Subject: Re: Injection rate option doesn't work

 

Hi Minneong, 

 

             What you are seeing is "Average network latency" and it is the number of cycles that a flit spends in the network. At saturation, this does not increase and what increases is the queuing delay at network interfaces. In the printStats function in GarnetNetwork_d.C, please uncomment the lines that print out the queuing latency and total latency to see those values. 

 

-Niket 

 

On Jan 24, 2010, at 7:49 AM, Minjeong Shin wrote:

Hi Niket,

 

I am using Garnet network-tester at http://www.princeton.edu/~niketa/garnet_files/tester-network-only.tgz

 

I wanted to get “injection rate – average latency” curve which is in the GARNET technical paper,

However, injection rate option (‘-i’ parameter) in the network-tester doesn’t work at all.

 

I checked the “Tester.C” file and injection_rate was just set to 0.1.

However, even if I change the injection_rate value, Average network latency never increased over 100.

And I don’t see any similarity between my result and the curve in the paper.

 

Is there anything I did wrong?

lease help me doing this.

 

Thank you.

 

Minjeong

 

--
Minjeong Shin
Dept. of Computer Science
Korea Advanced Institute of Science and Technology
+82-10-5553-2950