Re: [Starpu-devel] Performance issue of StarPU on Intel self-hosted KNL

[Mawussi Zounon <mawussi.zounon@manchester.ac.uk>]

Thanks Samuel,

I will perform a quick benchmark then be back to you.

Best regards,
--Mawussi
________________________________________
From: Samuel Thibault [samuel.thibault@inria.fr]
Sent: Monday, September 25, 2017 1:16 PM
To: Olivier Aumage; Mawussi Zounon; Negin Bagherpour; 
starpu-devel@lists.gforge.inria.fr; Jakub Sistek
Subject: Re: [Starpu-devel] Performance issue of StarPU on Intel self-hosted 
KNL

Samuel Thibault, on ven. 22 sept. 2017 11:48:12 +0200, wrote:
> Olivier Aumage, on ven. 22 sept. 2017 09:12:27 +0200, wrote:
> > The main reason for the initialization cost on KNL is the large number of 
> > cores and the fact that those cores are individually much less powerful 
> > and advanced than Broadwell's cores. Initializing libhwloc on the KNL 
> > takes about 0.5 to 1 second.
>
> And we do it twice, once for the whole architecture, and a second
> time in _starpu_build_tree to get only the structure of the
> architecture. Perhaps that second call could be avoided, it's probably
> less expensive to make build_tree cope with structure-useless hwloc
> object, than asking hwloc discovery a second time.

I have fixed this.

Samuel