dolfin team mailing list archive

["Garth N. Wells" <gnw20@xxxxxxxxx>]

On 23 September 2011 17:21, Anders Logg <logg@xxxxxxxxx> wrote:
> On Fri, Sep 23, 2011 at 04:50:33PM +0100, Garth N. Wells wrote:
>> On 22 September 2011 12:46, Johannes Ring <johannr@xxxxxxxxx> wrote:
>> > On Wed, Sep 21, 2011 at 1:19 PM, Johannes Ring <johannr@xxxxxxxxx> wrote:
>> >> On Wed, Sep 21, 2011 at 1:01 PM, Garth N. Wells <gnw20@xxxxxxxxx> wrote:
>> >>> On 21 September 2011 11:55, Johannes Ring <johannr@xxxxxxxxx> wrote:
>> >>>> On Wed, Sep 21, 2011 at 12:27 PM, Garth N. Wells <gnw20@xxxxxxxxx> wrote:
>> >>>>> On 21 September 2011 11:06, Johannes Ring <johannr@xxxxxxxxx> wrote:
>> >>>>>> On Wed, Sep 21, 2011 at 11:45 AM, Garth N. Wells <gnw20@xxxxxxxxx> wrote:
>> >>>>>>> A while ago, we used some Boost MPI but then removed it because of
>> >>>>>>> some older systems lack support. Could we start using it now? I would
>> >>>>>>> like to. It would make some parallel things a lot simpler. Would the
>> >>>>>>> buildbots need to be updated?
>> >>>>>>
>> >>>>>> Yes, some of them would need an update. Also, we would no longer be
>> >>>>>> able to provide packages for Ubuntu 10.04 LTS, which is by far the
>> >>>>>> Ubuntu version with the most downloads from the PPA.
>> >>>>>>
>> >>>>>
>> >>>>> OK, so the decision is whether or not to continue support for 10.04.
>> >>>>> Since I don't use 10.04 but I do use MPI, I vote for ditching 10.04
>> >>>>> and using Boost MPI. A compromise would be to use Boost MPI, and not
>> >>>>> provide parallel support in the 10.04 package.
>> >>>>>
>> >>>>> How do we deal with Swig 2 in 10.04? Or is it not required since the
>> >>>>> wrappers have already been generated?
>> >>>>
>> >>>> I have backported SWIG 2.0 to Lucid.
>> >>>>
>> >>>
>> >>> OK,  what about backporting Boost too? There are a few PPAs already, e.g.
>> >>>
>> >>>   https://launchpad.net/~infie/+archive/boost-1.47
>> >>>   https://launchpad.net/~gezakovacs/+archive/boost
>> >>
>> >> Yes, I will try to backport Boost in my test PPA
>> >> (https://launchpad.net/~johannr/+archive/test-ppa). I am just afraid
>> >> that it will break some of the other packages that depends on the
>> >> older Boost, but I will give it a shot.
>> >
>> > It seems to work out nicely. I only had to rebuild UFC against the new
>> > Boost packages and then everything ran smoothly.
>> >
>> > It will require some work on the buildbots if we start using Boost MPI.
>> >
>>
>> Does anyone else want to throw in an opinion on this?
>
> ok for me. Is the plan to keep the MPI:: utility functions and replace
> the implementation by boost? Or will we be using boost throughout? In
> particular, does it have a replacement for MPI::distribute?
>

I suggest keeping the functions in MPI.h.

Boost MPI won't replace MPI::distribute, but it will make the
internals of  MPI::distribute simpler and more general (e.g. handle
booleans, which we don't at the moment because they need to be treated
as a special case).

The two big advantages of Boost MPI are

1. It's templated, so we don't need *4+* versions of each function
(uint, int, double, bool, . . .)
2. It can handle various C++ STL objects seamlessly.

When do we want to start?

Garth


> --
> Anders
>