Ah yes.
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Pavan Balaji Sent: Thursday, January 31, 2008 10:48 AM To: [email protected] Subject: Re: [mpich2-core] MPICH2 Threading Overhead
Actually that's what I thought when I wrote the code, but the latency number is also being aggregated. That means we have to multiply by nt^2. That is, average latency = total_latency / nt (this is already there). But total messaging rate = nt / average_latency. I'm missing the second nt.
-- Pavan
On 01/31/2008 10:45 AM, Rajeev Thakur wrote:
No, I think it's taken care of in your new code because you are dividing latency by the number of threads.
Rajeev
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Pavan Balaji Sent: Thursday, January 31, 2008 10:44 AM To: [email protected] Subject: Re: [mpich2-core] MPICH2 Threading Overhead
Oh, good catch. I think it should be nthreads/latency. My bad.
-- Pavan
On 01/31/2008 10:36 AM, Rajeev Thakur wrote:
In the code I have, the message rate is calculated as nthreads/latency. However, the numbers below seem to be calculated as 1/latency. Which is right?
Rajeev
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Pavan Balaji Sent: Thursday, January 31, 2008 8:00 AM To: [email protected] Subject: Re: [mpich2-core] MPICH2 Threading Overhead
Below are the numbers while using MPI_PROC_NULL. The trend is the same. I guess the next step is to start instrumenting the code.
BG/P: ---- # MPI Message Rate Test with 4 Threads # nthreads Size Latency (us) Message Rate (MMPS) 1 0 1.02 0.981 2 0 1.21 0.825 3 0 2.48 0.403 4 0 3.78 0.265
Breadboard: ---------- # MPI Message Rate Test with 4 Threads # nthreads Size Latency (us) Message Rate (MMPS) 1 0 0.39 2.589 2 0 0.85 1.183 3 0 4.68 0.213 4 0 4.36 0.229
Thanks.
-- Pavan
-- Pavan Balaji http://www.mcs.anl.gov/~balaji
-- Pavan Balaji http://www.mcs.anl.gov/~balaji
-- Pavan Balaji http://www.mcs.anl.gov/~balaji