PetscSFWindowSetFlavorType

Set flavor type for MPI_Win creation

Synopsis

#include "petscsf.h" 
PetscErrorCode PetscSFWindowSetFlavorType(PetscSF sf, PetscSFWindowFlavorType flavor)

Logically Collective

Input Parameters

• sf - star forest for communication of type PETSCSFWINDOW

• flavor - flavor type

Options Database Key

• -sf_window_flavor - sets the flavor type CREATE, DYNAMIC, ALLOCATE or SHARED (see PetscSFWindowFlavorType)

Notes

Windows reuse follows these rules:

     PETSCSF_WINDOW_FLAVOR_CREATE: creates a new window every time, uses MPI_Win_create

     PETSCSF_WINDOW_FLAVOR_DYNAMIC: uses MPI_Win_create_dynamic/MPI_Win_attach and tries to reuse windows by comparing the root array. Intended to be used on repeated applications of the same SF, e.g.
       PetscSFRegisterPersistent(sf,rootdata1,leafdata);
       for i=1 to K
         PetscSFOperationBegin(sf,rootdata1,leafdata);
         PetscSFOperationEnd(sf,rootdata1,leafdata);
         ...
         PetscSFOperationBegin(sf,rootdata1,leafdata);
         PetscSFOperationEnd(sf,rootdata1,leafdata);
       endfor
       PetscSFDeregisterPersistent(sf,rootdata1,leafdata);

       The following pattern will instead raise an error
         PetscSFOperationBegin(sf,rootdata1,leafdata);
         PetscSFOperationEnd(sf,rootdata1,leafdata);
         PetscSFOperationBegin(sf,rank ? rootdata1 : rootdata2,leafdata);
         PetscSFOperationEnd(sf,rank ? rootdata1 : rootdata2,leafdata);

     PETSCSF_WINDOW_FLAVOR_ALLOCATE: uses MPI_Win_allocate, reuses any pre-existing window which fits the data and it is not in use

     PETSCSF_WINDOW_FLAVOR_SHARED: uses MPI_Win_allocate_shared, reusage policy as for PETSCSF_WINDOW_FLAVOR_ALLOCATE

See Also

PetscSF, PETSCSFWINDOW, PetscSFSetFromOptions(), PetscSFWindowGetFlavorType()

Level

advanced

Location

src/vec/is/sf/impls/window/sfwindow.c

Implementations

PetscSFWindowSetFlavorType_Window() in src/vec/is/sf/impls/window/sfwindow.c

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