I’m currently working on an implementation of a general PetscStream object. Currently it only supports Vector ops and has a proof of concept KSPCG, but should be extensible to other objects when finished. Junchao is also indirectly working on pipeline support in his NVSHMEM MR. Take a look at either MR, it would be very useful to get your input, as tailoring either of these approaches for pipelined algorithms is key. Best regards, Jacob Faibussowitsch (Jacob Fai - booss - oh - vitch) Cell: (312) 694-3391

On Jan 9, 2021, at 15:01, Mark Adams <[email protected]> wrote:

I would like to put a non-overlapping ASM solve on the GPU. It's not clear that we have a model for this.

PCApply_ASM currently pipelines the scater with the subdomain solves. I think we would want to change this and do a 1) scatter begin loop, 2) scatter end and non-blocking solve loop, 3) solve-wait and scatter begging loop and 4) scatter end loop.

I'm not sure how to go about doing this. * Should we make a new PCApply_ASM_PARALLEL or dump this pipelining algorithm and rewrite PCApply_ASM? * Add a solver-wait method to KSP?

Thoughts?

Mark