Local-only use of segments

[krzikalla]

Sec. 7.2.1 (gaspi_segment_alloc) reads:

After successful procedure completion, i. e. return value GASPI_SUCCESS, the
segment can be accessed locally. In case that there is a connection established to
a remote Gaspi process, it can also be used for passive communication between
the two Gaspi processes.

This sounds as if it cannot be used as the local segment in gaspi_wirte and gaspi_read. However, sec. 8.2.1 (gaspi_write) reads differently:

A valid gaspi_write communication request requires that the local and the
remote segment are allocated, that there is a connection between the local and
the remote Gaspi process and that the remote segment has been registered on
the local Gaspi process.

I guess the latter is intended. We should harmonize 7.2.1 accordingly.

To put this issue to an extreme: is it actually necessary to have local segments at all? Couldn't gaspi_write and the like just take a pointer to the local memory?

[mrahn]

Isn't the registration missing?

[end137]

Hi all, if I remember correctly, the course of discussion was something like the following: for IB you have to register your local memory as well as your remote memory for RDMA communication. If we don't have an explicit call for this, we'd have to hide this somewhere else and this would most probably lead to registering memory segments we don't even need (i.e. contrary to sparse infrastructure) Best, Vanessa

…

On 18.09.2018 09:25, Mirko Rahn wrote: Isn't the registration missing?

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[krzikalla]

Ok, then 8.2.1 must be clarified accordingly:

A valid gaspi_write communication request requires that the local and the
remote segment are allocated, that there is a connection between the local and
the remote Gaspi process , that the local segment has been registered on
the remote Gaspi process and that the remote segment has been registered on
the local Gaspi process.

Maybe there is a better wording.