This is likely in the context of a preconditioner for a composite solve, so the many BoomerAMG solvers will persist. They all get set up and then applied in sequence to the many scalar systems at each iteration of an outer method.
If hypre doesn't want to dup its communicators internally, then PETSc will dup a communicator for hypre, attach it to the outer communicator, and look for it each time a new hypre object is created. It's easy for PETSc (we've done this for PETSc since the early days), but a headache for other libraries. "Li, Ruipeng" <[email protected]> writes: > Hi, Fande, > > "For instance, if an application has multiple fields and each field will be > solved by a HYPRE solver, then we end up with multiple hypre solves. The > multiple hypre solves are not run simultaneously, instead, it will be run > one-by-one. If we assign the same communicator to the multiple hypre solves, > any potential tag conflict?" > > In this scenario, is just the solve phase of BoomerAMG one after another, or > also the setup of AMG? Since BoomerAMG takes the communicator from the A > matrix, if the entire hypre solve (setup + solve) is serial, there should be > no conflicts. > > -Ruipeng > > . -- .- .. .-.. / ..-. .-. --- -- / .-. ..- .. .--. . -. --. / .-.. .. > Ruipeng Li > Center for Applied Scientific Computing > Lawrence Livermore National Laboratory > P.O. Box 808, L-561 > Livermore, CA 94551 > phone - (925) 422-6037, email - [email protected] > > > ________________________________________ > From: Kong, Fande <[email protected]> > Sent: Tuesday, April 3, 2018 1:34 PM > To: hypre-support > Cc: Barry Smith; Derek Gaston; Li, Ruipeng; Osei-Kuffuor, Daniel; For users > of the development version of PETSc; Schroder, Jacob B.; [email protected]; > [email protected]; Wang, Lu > Subject: Re: [issue1595] Issues of limited number of MPI communicators when > having many instances of hypre boomerAMG with Moose > > > > On Tue, Apr 3, 2018 at 2:12 PM, Rob Falgout hypre Tracker > <[email protected]<mailto:[email protected]>> wrote: > > Rob Falgout <[email protected]<mailto:[email protected]>> added the comment: > > Hi Barry, > > Can you explain the scenario where multiple hypre solves would be working in > parallel with the same communicator? Thanks! > > Hi Rob, > > For instance, if an application has multiple fields and each field will be > solved by a HYPRE solver, then we end up with multiple hypre solves. The > multiple hypre solves are not run simultaneously, instead, it will be run > one-by-one. If we assign the same communicator to the multiple hypre solves, > any potential tag conflict? > > Fande, > > > > -Rob > > ____________________________________________ > hypre Issue Tracker <[email protected]<mailto:[email protected]>> > <https://urldefense.proofpoint.com/v2/url?u=http-3A__cascb1.llnl.gov_hypre_issue1595&d=DwIFaQ&c=54IZrppPQZKX9mLzcGdPfFD1hxrcB__aEkJFOKJFd00&r=DUUt3SRGI0_JgtNaS3udV68GRkgV4ts7XKfj2opmiCY&m=3KsQjTxI8eRWrSIJtB3o9NlBc4bEuuP4HxiT-BlMx3U&s=FjvfvXD21bX8LA2TAD-J6MWCJyMNm0aameRp_9nfLYs&e=> > ____________________________________________
