2023.02.16 Meeting Notes

Agenda

• Individual/group updates
• Getting started guide
• non-WIP PRs

Individual updates

JM

• started working on particle IO and went down rabbit hole
• needed to update MetaData (moved over from riot branch) with couple of improvements
  • performance: search by flags now uses a new MetaData cache (with support for sets of variables) -> remove the (potentially excessive cost by linearly go through all vars, which could be bad if number of vars goes to the hundreds)
  • FlagCollection that supports set arithmetic
  • discovered issue with ordered set as shared pointer objects for sparse var may change so the order may change (in different ways between different ranks) -> now addressing ordering by fixed, global index; which is also faster and should eventually go into VariablePack caching machinery
  • can now request user enrolled metadata flag by given name
  • variable pack by name will be ordered in the order of the name
  • LR should review (to check for compatibility with sparse) and PG will review for AthenaPK

BR

• working downstream

BP

• working on PEP1 with example in KHARMA with supporting documenation
• KHARMA is back to Parthenon develop
  • got new features
  • but had to remove the "solver" pieces that had to be rolled back from the riot PR
    • contains CG, BiCG, and more
    • plus supporting features in sparse
  • will add this as separate PR

PM

• downstream dev
• shout-out to feature of AddIteration, which is great!
• found bug in AthenaK due to missing fences before MPI comm

FG

• downstream dev
• need prolong/restrict for prim vars
• will give a talk at the APS meeting on AthenaPK/Parthenon

LR

• downstream dev
• thinking about refinement structures to find optimal meshes
• will ping JD with JM wrt CellVariable -> Variable transition (what's missing to get the PR across the finish line)
• looked at multi-threading the TaskList, ran into issues as Kokkos is not thread safe itself

TG

• has some resources again to contribute

PG

• Ascent PR basically ready (incl CI) but one thing is slightly off (in contact with Ascent devs)
• Open PR to yt main of Parthenon frontend
• Abstract for CUG paper on using parthenon-hydro in Frontier accepted
• Discussed test setup for AMR comparison between AthenaPK/Parthenon and AthenaK with JS

Getting started guide

• we should have sth like a getting started guide with focus basic concepts (in addition to dev doc and compile doc)
• could also look at KHARMA for some dev doc (more intro on modern C++)
• also need a full list of input parameters
• PG will create PR to move all doc to Sphinx and then we go from there
• TG will go through new (and then searchable doc) and create an issue to collect items that are missing/unclear/unexpected/...

Next meeting

Mar 2 (if quorum) otherwise Mar 9