Jayesh,<div> Thanks again for getting back to me. How do I broadcast "non-standard" datasets using MPI? For example, how do i broadcast unstructured grids to all the nodes? Also, should I use a barrier to hold all the processes till i'm done broadcasting?</div>
<div>Prashanth<br><br><div class="gmail_quote">On Tue, Dec 7, 2010 at 1:27 PM, Jayesh Krishna <span dir="ltr"><<a href="mailto:jayesh@mcs.anl.gov">jayesh@mcs.anl.gov</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
Hi,<br>
In your case it looks like you might be better off reading from one MPI process and broadcasting to others.<br>
<div class="im"><br>
Regards,<br>
Jayesh<br>
----- Original Message -----<br>
From: Prashanth <<a href="mailto:prashanth.dumpuri@gmail.com">prashanth.dumpuri@gmail.com</a>><br>
</div><div><div></div><div class="h5">To: Jayesh Krishna <<a href="mailto:jayesh@mcs.anl.gov">jayesh@mcs.anl.gov</a>>, <a href="mailto:mpich-discuss@mcs.anl.gov">mpich-discuss@mcs.anl.gov</a><br>
Sent: Tue, 07 Dec 2010 11:10:07 -0600 (CST)<br>
Subject: Re: [mpich-discuss] reading data into a parallel program<br>
<br>
Jayesh,<br>
Thanks for getting back to me. I'm not using MPI-IO functions. My datasets<br>
are unstructured grids and I have to use another toolkit (VTK) to read the<br>
files. I can store them in the binary format and they shouldn't be more than<br>
a few megabytes.<br>
My MPI processes are launched after i read the data and every processor<br>
requires knowledge of the complete dataset (in other words i cannot<br>
partition the data and split it across the available processors). Hope I<br>
answered your question correctly.<br>
So, given this should I let all the nodes read the input files?<br>
Thanks<br>
Prashanth<br>
<br>
On Tue, Dec 7, 2010 at 10:45 AM, Jayesh Krishna <<a href="mailto:jayesh@mcs.anl.gov">jayesh@mcs.anl.gov</a>> wrote:<br>
<br>
> Hi,<br>
> This will depend on how much data is read and where your MPI processes are<br>
> launched. Are you using MPI-IO functions (like MPI_File_read_all()) for<br>
> reading the data ?<br>
><br>
> Regards,<br>
> Jayesh<br>
> ----- Original Message -----<br>
> From: Prashanth <<a href="mailto:prashanth.dumpuri@gmail.com">prashanth.dumpuri@gmail.com</a>><br>
> To: <a href="mailto:mpich-discuss@mcs.anl.gov">mpich-discuss@mcs.anl.gov</a><br>
> Sent: Mon, 06 Dec 2010 10:44:53 -0600 (CST)<br>
> Subject: [mpich-discuss] reading data into a parallel program<br>
><br>
> All,<br>
> I have a main program that reads input data from files and 3<br>
> filters/classes instantiated within the main program that process the<br>
> datasets. I have parallelized 2 of those 3 classes (using MPICH2). Is it<br>
> faster to read data on the root processor and then broadcast it to all the<br>
> child nodes or should I let all the nodes read the data?<br>
> I'm running my main program on a Windows XP machine with an Intel Quad<br>
> core processor.<br>
> Thanks<br>
> Prashanth<br>
><br>
><br>
<br>
</div></div></blockquote></div><br></div>