smsc/xpmem: alignment and stack memory space

[devreal]

This PR addresses two issues identified in https://github.com/open-mpi/ompi/issues/10121:

1. The aligned upper bound was off by 1.
2. We may not be able to map the full aligned range if the memory points to the stack. In that case we should try again with the requested upper bound.

Signed-off-by: Joseph Schuchart [email protected]

[hjelmn]

Bounds when it comes to rcache registration are the last byte of the range. Probably doesn't matter much here as no rcache is in use.

[devreal]

I changed the fallback to align to the actual page size, which seems to work as well and reduces the number of times we may need to remap until we have mapped all the relevant stack positions mapped.

[devreal]

@hjelmn Can you please take a look at this PR?

[devreal]

Rebased to current main. Can someone please review?

[bwbarrett]

bot:aws:retest

[awlauria]

@devreal I think you'll want to rebase and force push again.

[awlauria]

bot:aws:retest