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ammarhakim / gkyl

This is the main source repo for the Gkeyll 2.0 code. Please see gkeyll.rtfd.io for details.
https://gkeyll.readthedocs.io/en/latest/
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GPU hackathon 2023: twist-shift BCs and multi-CPU/GPU GK field solve #129

Closed manauref closed 1 year ago

manauref commented 1 year ago

This goes with g0's PR 191: https://github.com/ammarhakim/gkylzero/pull/191

Work done as part of the 2023 NERSC GPU hackathon, including:

  1. Putting twist-shift BCs in g0 and on GPUs.
  2. Adding support for multi-CPU/GPU 1x and 3x GK field solves.

This effort also included work on neutrals and on correcting Maxwellians (mostly in g0).

Some notes about 1 and 2 above (and see PR 191 in g0):

  1. We need to improve its performance, perhaps by batching over vpar and mu. 2a. Corresponding changes are needed still for Vlasov-Poisson and 2x2v GK. 2b. It'd be good to have someone produce a scaling of the GK solver on Perlmutter (@mrquell ?). 2c. Boundary fluxes in multi-GPU runs still appear off. Will fix that separately.