[ofa-general] Re: [PATCH 5 of 5] mlx4: Do not allocate an extra (unneeded) CQE when creating a CQ

[Roland Dreier]

 > You are correct, that is an unfortunate side-effect of the change, that
 > I missed. The largest CQ that an old libmlx4 will accept is 0x3fffff
 > (hard-coded in file libmlx4/src/verbs.c, procedure mlx4_create_cq() ).
 > The new limit returned in dev_lim is 0x400000.
 > 
 > Does this mean that you prefer to increment the ABI?

I'm not sure it's worth breaking the ABI for.

Does it seem OK if we leave the kernel alone (well, change the
in-kernel rounding, but leave the user-kernel interface the same),
apply the libmlx4 change, and just have the limit on the CQ size be
off by one?

We can fix everything if there's a reason for an ABI break later.

 - R.