[openib-general] Lustre over OpenIB Gen2
halr at voltaire.com
Thu Nov 17 12:37:08 PST 2005
On Thu, 2005-11-10 at 14:50, Roland Dreier wrote:
> Eric> Or is it better to use FMR pools and take the map/unmap
> Eric> overhead? If so, is there a way to know when the unmap
> Eric> actually hits the hardware and my memory is safe?
> FMRs are only supported on Mellanox HCAs at the moment. But they do
> have some advantages, like allowing you to convert a bunch of pages
> into a single virtually contiguous region. You can use the
> ib_flush_fmr_pool() function to make sure that all unmapped FMRs are
> really and truly flushed, but that is a slow operation (since it
> incurs the penalty of flushing all in-flight operations in the HCA).
Assuming one had a machine with a mix of vendor HCAs (Mellanox,
PathScale), how would one determine what hardware/driver was being used
(assuming one wanted to take advantage of a proprietary feature which
was supported only on one or the other) ? If it that EINVAL or the like
is returned from the ones that don't support that feature ?
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