[petsc-dev] PetscSection

[Jed Brown]

Matthew Knepley <knepley at gmail.com> writes:
> I wish the guy who write PetscSF believed in types smaller than int. Just
> because they are small, does not mean they
> cannot achieve great things. MPI_BYTE is the Little Type That Could.

You have a (rank, offset) per unit.  If unit is one byte, then you have
inflated the metadata by at least 8x (16x when 64-bit-indices).  That
is, you're using 8 bytes of metadata to move each byte of payload.
That's silly; we need a different model.

It looks like Shri would be just fine with 4 separate sections, each
with homogeneous-sized units.
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