[openib-general] question about poll_cq()

[Joerg Zinke]

hi,

i hope it's ok to ask this question here.
i just want to know more about poll_cq().
the standard seems to define only the input/ouput-params.
after reading the code i figured out that there is some kind of
"mapping" from libibverbs to the device specific "plugin" (mthca).
so it looks like that the ibv_poll_cq() call from the userspace (e.g.
ibv_xx_pingpong) finally ends in a call of: mthca_poll_cq() in
mthca_cq.c

so my question is: can someone give me a brief summary what
mthca_poll_cq (or mthca_poll_one()) is really doing?
i want to know how polling the completion queue really
works, there must be some kind of low-level acknowledge/response-
message if a new entry enters the cq?
where is the completion queue really located (on a rdma operation) -
local or remote?

or maybe give me some hints/links to docs where i can read more
about it.
thanks.

regards,

joerg zinke