[ofa-general] How much pinned memory each QP needs ?

[Roland Dreier]

 > If I change max_send_wr=16, inline_data=16, the memory per QP will
 > be 16*16 = 256 bytes ?

With existing driver code, there's no way to go below 4KB because of
the way memory is pinned.  Also, the minimum work request size is
currently 64 bytes.  But max_send_wr=16, max_inline_data=16 should get
you pretty close to 4KB.  Maybe 8KB.

 > I am asking Mellanox engineer, is there any document or will document the formula  ?

It actually somewhat depends on the driver, because the way things are
implemented has some flexibility.

 - R.