Present: Danilo, Guillerme, Xavi, Enrico, Enric, Lorenzo, Philippe, Kim, Gerrim, Jim
* Guillerme: report on the progress about the veccore integration and coherency with vc and vecgeom
* Danilo: integrate new ctors in the TDF
- Make sure to throw an informative message if more than one tree is present in the file(s)
* Danilo: investigate the TProfiles in TDF, investigate usage of histos with buffers
* Danilo: PR #364, integrate
* Xavi, Danilo: iron out the issue streaming the TSeq between processes
* Gerri, Enric, Xavi, Danilo: identify a chunking (packetising) procedure for MT, MP, collections and trees (perhaps respecting clusters' granularity a la TTreeProcessor)
* Xavi: implement Kahan summation to debug the different results in the likelihood benchmark based on multiprocessing
* Enric, Danilo: assess the difficulty of enabling TTreeProcessorMT also in the non imt builds, absorbing the duality of the imt/non-imt code path at the level of the ttreeprocessor implementation rather than TDF.
* 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: deliver PR1 for vectorisation in math to be integrated in ROOT as well as the associated tests
* Guilherme: if possible, report on the status of the integration of veccore
- Created an independent version, working to integrate it in vecgeom and ROOT. Start from vecgeom because smaller and quicker during the compilation
- Challenge: Get vecgeom, vc, veccore coherently - needed a bit more time to make it work
- Issues with the VC integration and Ninja: working on those
* Xavi: communicate to Guilherme the issue he had with vecore
* Danilo, Enrico, Enric: decide an interface for trees on multiple files (or chains)
* Danilo: make progress on the 2D and 3D histos
* Danilo: merge PR 337 and tests
* Action Xavi: check the table at slide 12 pres 2, redo numbers only with 4 physical cores.
* Action Xavi: chunk the work in N parts with N being the number of processes.
* Action Xavi/Danilo: Work out the difficulty streaming the double_v.
o ProcessExecutor: creating a lot of workers with many points. Implement the interface for chunking which was there in the TThreadExecutor into the TProcessExecutor (#364)
o Solved with the ifdef techinque the streaming of veccore types
o Problem: issues in the likelihood calculations, idea of Guillerme: try out a different backend. But in the mt case veccore works.
o TDataFrame: Philippe proposes that if we have more than one tree, we should throw rather than pick the "first" one.
o Kim: the exception message should be informartive
o Gerri: we accept the challenge of inglobating the multiprocessing as well as distributed system
o Lambda Macro:
- we should check if this solution suffers from "comma related" problems
- other potential problem: using quotes
Guillerme asked gsoc about packaging HEP software within the Gentoo community
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