About adding OMPT into GNU's libgomp

[Harald Servat]

2015-04-13 12:53 GMT+02:00 Jakub Jelinek <jakub@redhat.com>:
>
> The only thing I'd like to say is that it would be nice if the changes
> didn't affect performance of non-analyzed/traced apps, so if changes to hot
> code paths are needed, they should be done with care, guarded with
> __builtin_expect and benchmarked that they don't slow normal OpenMP code
> paths significantly.

  The OMPT's phisolosophy is to limit as much as possible its
overhead. Still, we'll follow your indications in order to keep the
overhead as low as possible.

>>   If there's nobody working on that, how should we start? According to
>> the GCC webpage, GCC 5 is open for regression and doc fixes only [2],
>> so it could considered mature enough to be a starting point? Or should
>> we start in GCC 4.9.x? That being said, I've seen that there's a copy
>> of GCC in GitHub [3]; should we clone it, branch to GCC 5 (if that
>> exists), and then work on a local branch until we can send you some
>> patches? Or do you suggest a different work plan?
>
> Please see what Jonathan wrote.  You really should start working on a branch
> from the trunk, and work towards incorporating it into the trunk (stage1
> of GCC 6, where the trunk is open for new features, closes usually in
> November).

  Thank you very much.

>         Jakub



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