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Subject: Re: [OMPI devel] RFC: convert send to ssend
From: Sylvain Jeaugey (sylvain.jeaugey_at_[hidden])
Date: 2009-08-24 11:54:34


For the record, I see an big interest in this.

Sometimes, you have to answer calls for tender featuring applications that
must work with no code change, even if the code is completely not
MPI-compliant.

That's sad, but true (no pun intended :-))

Sylvain

On Mon, 24 Aug 2009, George Bosilca wrote:

> Do people know that there exist tools for checking MPI code correctness?
> Many, many tools and most of them are freely available.
>
> Personally I don't see any interest of doing this, absolutely no interest.
> There is basically no added value to our MPI, except for a very limited
> number of users, and these users if they manage to write a parallel
> application that need this checking I'm sure they will greatly benefit from a
> real tool to help them correct their MPI code.
>
> As a side note, a very similar effect can be obtained by decreasing the eager
> size of the BTLs to be equal to the size of the match header, which is about
> 24 bytes.
>
> george.
>
> On Aug 24, 2009, at 11:11 , Samuel K. Gutierrez wrote:
>
>> Hi Jeff,
>>
>> Sounds good to me.
>>
>> Samuel K. Gutierrez
>>
>>
>> Jeff Squyres wrote:
>>> The debug builds already have quite a bit of performance overhead. It
>>> might be desirable to change this RFC to have a similar tri-state as the
>>> MPI parameter checking:
>>>
>>> - compiled out
>>> - compiled in, always check
>>> - compiled in, use MCA parameter to determine whether to check
>>>
>>> Adapting that to this RFC, perhaps something like this:
>>>
>>> - compiled out
>>> - compiled in, always convert standard send to sync send
>>> - compiled in, use MCA parameter to determine whether to convert standard
>>> -> sync
>>>
>>> And we can leave the default as "compiled out".
>>>
>>> Howzat?
>>>
>>>
>>> On Aug 23, 2009, at 9:07 PM, Samuel K. Gutierrez wrote:
>>>
>>>> Hi all,
>>>>
>>>> How about exposing this functionality as a run-time parameter that is
>>>> only
>>>> available in debug builds? This will make debugging easier and won't
>>>> impact the performance of optimized builds. Just an idea...
>>>>
>>>> Samuel K. Gutierrez
>>>>
>>>>>
>>>>> ----- "Jeff Squyres" <jsquyres_at_[hidden]> wrote:
>>>>>
>>>>>> Does anyone have any suggestions? Or are we stuck
>>>>>> with compile-time checking?
>>>>>
>>>>> I didn't see this until now, but I'd be happy with
>>>>> just a compile time option so we could produce an
>>>>> install just for debugging purposes and have our
>>>>> users explicitly select it with modules.
>>>>>
>>>>> I have to say that this is of interest to us as we're
>>>>> trying to help a researcher at one of our member uni's
>>>>> to track down a bug where a message appears to go missing.
>>>>>
>>>>> cheers!
>>>>> Chris
>>>>> --
>>>>> Christopher Samuel - (03) 9925 4751 - Systems Manager
>>>>> The Victorian Partnership for Advanced Computing
>>>>> P.O. Box 201, Carlton South, VIC 3053, Australia
>>>>> VPAC is a not-for-profit Registered Research Agency
>>>>> _______________________________________________
>>>>> devel mailing list
>>>>> devel_at_[hidden]
>>>>> http://www.open-mpi.org/mailman/listinfo.cgi/devel
>>>>>
>>>>
>>>> _______________________________________________
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>>>> devel_at_[hidden]
>>>> http://www.open-mpi.org/mailman/listinfo.cgi/devel
>>>>
>>>
>>>
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