Re: [OMPI users] "Re: Best way to overlap computation and transfer using MPI over TCP/Ethernet?"

2009-06-08 Thread Lars Andersson
On Mon, Jun 8, 2009 at 11:07 PM, Lars Andersson<lars...@gmail.com> wrote: > I'd say that your own workaround here is to intersperse MPI_TEST's > periodically. This will trigger OMPI's pipelined protocol for large > messages, and should allow partial bursts of progress while you're

[OMPI users] "Re: Best way to overlap computation and transfer using MPI over TCP/Ethernet?"

2009-06-04 Thread Lars Andersson
>> I've been trying to get overlapping computation and data transfer to >> work, without much success so far. > > If this is so important to you, why do you insist in using Ethernet > and not a more HPC-oriented interconnect which can make progress in > the background ? We have a medium sized

[OMPI users] Best way to overlap computation and transfer using MPI over TCP/Ethernet?

2009-06-04 Thread Lars Andersson
Hi all, I've been trying to get overlapping computation and data transfer to work, without much success so far. What I'm trying to achieve is: NODE 1: * Post nonblocking send (30MB data) NODE 2: 1) Post nonblocking receive 2) do local work, while data is being received 3)

Re: [OMPI users] Receiving MPI messages of unknown size

2009-06-04 Thread Lars Andersson
> On Thu, 2009-06-04 at 14:54 +1000, Lars Andersson wrote: >> Hi Gus, >> >> Thanks for the suggestion. I've been thinking along those lines, but >> it seems to have drawbacks. Consider the following MPI conversation: >> >> Time NODE 1 NODE 2 >

Re: [OMPI users] Receiving MPI messages of unknown size

2009-06-04 Thread Lars Andersson
On Thu, Jun 4, 2009 at 2:54 PM, Lars Andersson <lars...@gmail.com> wrote: > Hi Gus, > > Thanks for the suggestion. I've been thinking along those lines, but > it seems to have drawbacks. Consider the following MPI conversation: > > Time            NODE 1        

Re: [OMPI users] Receiving MPI messages of unknown size

2009-06-04 Thread Lars Andersson
around this? Am I missing something? /Lars On Thu, Jun 4, 2009 at 2:34 PM, Lars Andersson <lars...@gmail.com> wrote: > Hi Lars > > I wonder if you could always use blocking message passing on the > preliminary send/receive pair that transmits the message size/header, >

[OMPI users] Receiving MPI messages of unknown size

2009-06-03 Thread Lars Andersson
using ordinary 1Gbit ethernet. Best regards, Lars Andersson

Re: [OMPI users] Oversubscription performance problem

2008-04-09 Thread Lars Andersson
On Fri, Apr 4, 2008 at 4:30 PM, Lars Andersson <lars...@gmail.com> wrote: > Hi, > > I'm just in the progress of moving our application from LAM/MPI to > OpenMPI, mainly because OpenMPI makes it easier for a user to run > multiple jobs(MPI universa) simultaneously. Thi

[OMPI users] Oversubscription performance problem

2008-04-04 Thread Lars Andersson
Hi, I'm just in the progress of moving our application from LAM/MPI to OpenMPI, mainly because OpenMPI makes it easier for a user to run multiple jobs(MPI universa) simultaneously. This is useful if a user wants to run smaller experiments without disturbing a large experiment running in the