Re: [Starpu-devel] Fwd: Strong interest in contributions and integrations

[Samuel Thibault <samuel.thibault@inria.fr>]

Hello,

Thanks Andra for the good feedback :) Just additional comments here:

Andra Hugo, on Mon 23 May 2016 12:07:12 +0200, wrote:
> 1. Do you measure energy or power? Maybe the field names don't match 
> properly(you store the energy value in the power field).

Perhaps the field names were improperly chosen :)

> I am however a little bit worried about interfering with the application's 
> cmd line parameters. We usually use env variables for runtime options for 
> starpu.

Yes, please do not use cmd line parameters, they become a nightmare when
combined with mpirun, simgrid, etc. environment variable pose way less
problems :)

> 10. This is more like a suggestion: In order to monitor the processors you 
> create a set of threads to take care of this. StarPU also has its own set 
> of threads. Leaving the OS deal with the context switch might affect 
> performance. Did you consider maybe using starpu's threads instead?  I 
> understand that your approach client server is definitely a better software 
> engineering solution, and it can then be easily integrated in any software 
> without modifying the code, but the overhead might be significant. 

If there is only a couple of communication between threads for each
task, it would seem OK to me, provided that there is no synchronization,
only signalling (I haven't read the source, so I don't know how they
communicate). Otherwise it will become a bottleneck that will pose
problem.

Samuel