ROOT Parallelisation, Performance and Programming Model Meeting

Thursday 16 Mar 2017, 16:00 → 18:25 Europe/Zurich

42/R-022 (CERN)

Danilo Piparo (CERN)

CERN number: 71400 Extension: 109284483#

Present: Danilo

Old Actions:

* Lorenzo: integrate PR2 of Xavi (#367) about vectorisation

* Lorenzo, Danilo: merge VecCore PR once discussion about it is complete
  - Now the comments are all integrated
  - Need to discuss further involving Pere if needed

* Danilo: integrate new ctors taking a TEntryList in the TDF
   - Make sure to throw an informative message if more than one tree is present in the file(s)
   --> This is pending until the creation of TEntryLists is addressed with an Action.

* Gerri, Enric, Xavi, Danilo: identify a chunking (packetising) procedure for MT, MP, collections and trees (perhaps respecting clusters' granularity a la TTreeProcessor)

* Xavi: Slide 7 2N debug nasty scaling obtained. Ideas:
   - With perf count the page faults (Pere's idea).
   - Artificially increase the work to see if the overhead is less.
   - Try only one worker.

* Xavi: try fma with Ofast before ruling that out

New Actions:

* Danilo: investigate fallback mechanism with backquotes for branch names which are not c++ names

Open Actions:

Closed Action:

----

Jim:

Proposal to add a feature to ROOT. Add any ROOT function from numpy: through jit and cling. Query system uses numpy ufunc as a way to identify functions which are written in C++. Jit the adaptor code for numpy around C++ functions.

 

This will be presented in the PPP meeting on Thursdays, even in at the stage of prototype and when something substantial is available in the Monday meeting.

The deliverable is a PR with the new functionality.

 

 

16:00 → 17:00 Round table

ppp_20160316.pdf