Accéder au contenu.
Menu Sympa

starpu-devel - Re: [Starpu-devel] Problem with performance model calibration

Objet : Developers list for StarPU

Archives de la liste

Re: [Starpu-devel] Problem with performance model calibration


Chronologique Discussions 
  • From: Mirko Myllykoski <mirkom@cs.umu.se>
  • To: Samuel Thibault <samuel.thibault@inria.fr>, starpu-devel@lists.gforge.inria.fr
  • Subject: Re: [Starpu-devel] Problem with performance model calibration
  • Date: Fri, 5 Jun 2020 15:01:11 +0200
  • Authentication-results: mail3-smtp-sop.national.inria.fr; spf=None smtp.pra=mirkom@cs.umu.se; spf=Pass smtp.mailfrom=mirkom@cs.umu.se; spf=None smtp.helo=postmaster@mail.cs.umu.se
  • Ironport-phdr: 9a23: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
  • List-archive: <http://lists.gforge.inria.fr/pipermail/starpu-devel/>
  • List-id: "Developers list. For discussion of new features, code changes, etc." <starpu-devel.lists.gforge.inria.fr>
  • Organization: Umeå University / HPC2N

I will check if that --disable-cuda-memcpy-peer flag is still relevant with the last versions of StarPU. It will probably take awhile since I have only limited access to GPUs right now.

- Mirko

On 2020-06-05 14:19, Samuel Thibault wrote:
Mirko Myllykoski, le ven. 05 juin 2020 14:13:35 +0200, a ecrit:
As you said, this probably does not matter when scheduling is
concerned but I can see how it could impact the performance models.

Yes, sure, but we use the performance models *for* the scheduling :)

I should also mention that I am compiling StarPU with the
--disable-cuda-memcpy-peer flag enabled. This seems to improve the
performance (sometimes significantly)

That's surprising. It'd be useful to investigate in traces how you can
get a performance improvement since this option basically adds *more*
synchronization within CUDA.

I can see how this could cause problems if the CUDA threads is busy
doing something else while a task starts/finishes.

Yes, that would perturbate performance models a lot since it'd make CUDA
report kernel termination only after some other terminations as well.
Again, the performance model getting affected is actually what we want
since that's what the scheduler will be faced to.

Samuel





Archives gérées par MHonArc 2.6.19+.

Haut de le page