[cctbxbb] Should we enable boost threads in bootstrap?

Tue Aug 1 13:16:59 PDT 2017

Lee,

End game for us is moving to “proper” threading i.e. lots of threads / cores working on one problem in one address space - be it regular 20 core xeon or 64 core KNL

Boost threads came up in conversation today as a C++11 like threading model, so I wondered if it would be a stepping stone...

Don’t have this book, maybe should get it….

Cheers Graeme

On 1 Aug 2017, at 18:14, Lee O'Riordan <loriordan at lbl.gov<mailto:loriordan at lbl.gov>> wrote:

Graeme, Nigel,

I would be a little bit worried about Boost threads when it comes to our KNL port of cctbx. In this instance the use of OpenMP or Intel TBB (at least accordingly to Intel docs) would be optimal over boost threads (or pthreads, etc.)[see Intel Xeon Phi High Performance Programming, KNL edition P155 --- no ebook, sorry]. That being said, there is no way to know unless we try it out first, but it isn't something we can test right now.

As for Threads vs MP, this again falls into our KNL port, where threads would be better suited (and become a necessity for optimal performance) when running on high-core count devices. If the OpenMP functionality exists, then maybe this would be a more portable way of taking advantage of all cores/hyperthreads.

In this instance I think turning boost threads on for a build-by-build basis would be better, rather than as a default? Though if I am wrong, feel free to correct me.

Best,
Lee.

On Tue, Aug 1, 2017 at 9:36 AM, Nigel Moriarty <nwmoriarty at lbl.gov<mailto:nwmoriarty at lbl.gov>> wrote:
Graeme

The short answer is "Why?" but that may start a very long discussion. There are a number of multiprocessing modules in easy_mp that seem to cover all the bases. Are there situations where threading is "better" to multiprocessing?

Articles on multiprocessing in cctbx.

https://www.phenix-online.org/newsletter/CCN_2017_01.pdf#page=6

https://www.phenix-online.org/newsletter/CCN_2013_07.pdf

https://www.phenix-online.org/newsletter/CCN_2013_01.pdf

Cheers

Nigel

---
Nigel W. Moriarty
Building 33R0349, Molecular Biophysics and Integrated Bioimaging
Lawrence Berkeley National Laboratory
Berkeley, CA 94720-8235
Phone : 510-486-5709<tel:(510)%20486-5709>     Email : NWMoriarty at LBL.gov<mailto:NWMoriarty at LBL.gov>
Fax   : 510-486-5909<tel:(510)%20486-5909>       Web  : CCI.LBL.gov<http://cci.lbl.gov/>

On Tue, Aug 1, 2017 at 7:54 AM, <Graeme.Winter at diamond.ac.uk<mailto:Graeme.Winter at diamond.ac.uk>> wrote:
Afternoon all,

Should we do this? Any opinions? Could be useful for threads in a semi-portable way...

Thanks & cheerio Graeme

--
This e-mail and any attachments may contain confidential, copyright and or privileged material, and are for the use of the intended addressee only. If you are not the intended addressee or an authorised recipient of the addressee please notify us of receipt by returning the e-mail and do not use, copy, retain, distribute or disclose the information in or attached to the e-mail.
Any opinions expressed within this e-mail are those of the individual and not necessarily of Diamond Light Source Ltd.
Diamond Light Source Ltd. cannot guarantee that this e-mail or any attachments are free from viruses and we cannot accept liability for any damage which you may sustain as a result of software viruses which may be transmitted in or with the message.
Diamond Light Source Limited (company no. 4375679). Registered in England and Wales with its registered office at Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, United Kingdom

_______________________________________________
cctbxbb mailing list
cctbxbb at phenix-online.org<mailto:cctbxbb at phenix-online.org>
http://phenix-online.org/mailman/listinfo/cctbxbb

_______________________________________________
cctbxbb mailing list
cctbxbb at phenix-online.org<mailto:cctbxbb at phenix-online.org>
http://phenix-online.org/mailman/listinfo/cctbxbb

_______________________________________________
cctbxbb mailing list
cctbxbb at phenix-online.org<mailto:cctbxbb at phenix-online.org>
http://phenix-online.org/mailman/listinfo/cctbxbb