Well that's suboptimal. What are my options for 100% GPU solves with no host transfers?
On Tue, Jan 10, 2023, 2:23 PM Barry Smith <[email protected]> wrote: > > > On Jan 10, 2023, at 2:19 PM, Mark Lohry <[email protected]> wrote: > > Is DILU a point-block method? We have -pc_type pbjacobi (and vpbjacobi if >> the node size is not uniform). The are good choices for scale-resolving CFD >> on GPUs. >> > > I was hoping you'd know :) pbjacobi is underperforming ilu by a pretty > wide margin on some of the systems i'm looking at. > > We don't have colored smoothers currently in PETSc. >> > > So what happens under the hood when I run -mg_levels_pc_type sor on GPU? > Are you actually decomposing the matrix into lower and computing updates > with matrix multiplications? Or is it just the standard serial algorithm > with thread safety ignored? > > > It is running the regular SOR on the CPU and needs to copy up the vector > and copy down the result. > > > On Tue, Jan 10, 2023 at 1:52 PM Barry Smith <[email protected]> wrote: > >> >> We don't have colored smoothers currently in PETSc. >> >> > On Jan 10, 2023, at 12:56 PM, Jed Brown <[email protected]> wrote: >> > >> > Is DILU a point-block method? We have -pc_type pbjacobi (and vpbjacobi >> if the node size is not uniform). The are good choices for scale-resolving >> CFD on GPUs. >> > >> > Mark Lohry <[email protected]> writes: >> > >> >> I'm running GAMG with CUDA, and I'm wondering how the nominally serial >> >> smoother algorithms are implemented on GPU? Specifically SOR/GS and >> ILU(0) >> >> -- in e.g. AMGx these are applied by first creating a coloring, and the >> >> smoother passes are done color by color. Is this how it's done in >> petsc AMG? >> >> >> >> Tangential, AMGx and OpenFOAM offer something called "DILU", diagonal >> ILU. >> >> Is there an equivalent in petsc? >> >> >> >> Thanks, >> >> Mark >> >> >
