I do not own a Rasberry Pi. Is this thing self-hosted, hence you are driving the Hydra download+build from a wimpy ARM core? Or is your Pi attached to a real computer? In case it wasn't obvious from the shell prompt ("Jeffs-MacBook-Pro:tmp jhammond"), I was timing on a Macbook Pro, which happens to have a 2.5 GHz Intel Core i7 quad-core processor. When I time on the oldest processor to which I have access (PPC970MP 2.5 GHz circa 2007), the whole process takes twice as long (77 seconds). In both cases, I built in /tmp, which on Linux is a ramdisk (http://en.wikipedia.org/wiki/Tmpfs). If building Hydra is a bottleneck because the Pi is too slow for basic operations like download a file, unpack it and run gcc on its contents, then you should go back to your very first statement ("I am trying to use two raspberry-pi to sample and then process some data") and consider whether or not what you're doing makes sense. If a computer can't compile very simple software like Hydra in a reasonable amount of time, I fail to see how it can be used to process data quickly. While configure isn't necessarily a good model for data analysis, I imagine that your time is best spent implementing and running your data analysis on a computer with more substantial processing power. I guess I should also point out that you should be able to cross compile Hydra if you have the appropriate cross-compiler toolchain, hence you can download and build Hydra on an x86 laptop and then merely copy the resulting binary over to your toy processor. Best, Jeff On Sun, Jun 16, 2013 at 12:26 PM, Lee, Eibhlin <[email protected]> wrote:

Unfortunately my past experience with hydra is VERY different. I'm baffled as to how you managed to do it so quickly. Surely you have to download the file from mpich.org then unzip (which takes at least 5 mins) then configure (up to an hour) make (a long time as well) and finally make install (another chance in which you can go have a cuppa). And then get the image and put it onto another device which first needs formatting; for me that takes anywhere between 10 minutes and an hour. What did you do so that it took so little time? Eibhlin ________________________________________ From: [email protected] [[email protected]] on behalf of Jeff Hammond [[email protected]] Sent: 16 June 2013 18:19 To: [email protected] Subject: Re: [mpich-discuss] Running an mpi program that needs to access /dev/mem

...

I did not want to spend a whole day installing hydra instead of smpd if it would not work.

It took me 41 seconds to install Hydra ex nihilo and I didn't even use "make -j". The argument that installation time is a bottleneck is invalid. smpd is not supported and you shouldn't use it. End of discussion.

Jeff

<snip> ALL DONE Sun Jun 16 12:16:12 CDT 2013

real 0m40.912s user 0m17.405s sys 0m11.028s

Jeffs-MacBook-Pro:tmp jhammond$ cat auto #!/bin/bash date wget http://www.mpich.org/static/downloads/3.0.4/hydra-3.0.4.tar.gz && \ tar -xzf hydra-3.0.4.tar.gz && \ cd hydra-3.0.4 && \ mkdir build && \ cd build && \ ../configure CC=gcc --prefix=/tmp/hydra-install && \ make && \ make install && \ make check echo "ALL DONE" date

-- Jeff Hammond Argonne Leadership Computing Facility University of Chicago Computation Institute [email protected] / (630) 252-5381 http://www.linkedin.com/in/jeffhammond https://wiki.alcf.anl.gov/parts/index.php/User:Jhammond ALCF docs: http://www.alcf.anl.gov/user-guides _______________________________________________ discuss mailing list [email protected] To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss _______________________________________________ discuss mailing list [email protected] To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss

-- Jeff Hammond Argonne Leadership Computing Facility University of Chicago Computation Institute [email protected] / (630) 252-5381 http://www.linkedin.com/in/jeffhammond https://wiki.alcf.anl.gov/parts/index.php/User:Jhammond ALCF docs: http://www.alcf.anl.gov/user-guides