hello everyone,I'm a research assistant at Tsinghua University.
And now,i begin to study the MPI for DSP.
Can anybody tell me something on this field?
thanks.
laij...@mails.tsinghua.edu.cn
2006-03-07
Hi David
yep they do (reduce the values to a single location) and in a tree
topology it would look something like the following:
proc 3 4 5 6
local values 30 40 50 60
partial sums - -
On Mar 6, 2006, at 3:38 PM, Xiaoning (David) Yang wrote:
I'm not quite sure how collective computation calls work. For
example, for an MPI_REDUCE with MPI_SUM, do all the processes
collect values from all the processes and calculate the sum and put
result in recvbuf on root? Sounds strange.
I'm not quite sure how collective computation calls work. For example, for
an MPI_REDUCE with MPI_SUM, do all the processes collect values from all the
processes and calculate the sum and put result in recvbuf on root? Sounds
strange.
David
* Correspondence *
> From: Jeff Squyres
> Re
Generally, yes. There are some corner cases where we have to
allocate additional buffers, but that's the main/easiest benefit to
describe. :-)
On Mar 6, 2006, at 11:21 AM, Xiaoning (David) Yang wrote:
Jeff,
Thank you for the reply. In other words, MPI_IN_PLACE only
eliminates data
mo
Jeff,
Thank you for the reply. In other words, MPI_IN_PLACE only eliminates data
movement on root, right?
David
* Correspondence *
> From: Jeff Squyres
> Reply-To: Open MPI Users
> Date: Fri, 3 Mar 2006 19:18:52 -0500
> To: Open MPI Users
> Subject: Re: [OMPI users] MPI_IN_PLACE
>
Second topic:
I am using 3 processors
I am calling a series of MPI_SCATTER which work when I send
messages of
5 ko to the other processors, fails at the second scatter if I sent
messages of ~10 ko, and fails at the first scatter for bigger
messages.
The message is:
What is "ko" -- d
