Re: [PATCH 1/4] libibmad: Distinguish timed out from other errors

[Jason Gunthorpe <jgunthorpe-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>]

On Sun, Apr 10, 2011 at 06:33:03AM -0400, Hal Rosenstock wrote:
> On 4/9/2011 1:12 PM, Jason Gunthorpe wrote:
> > On Sat, Apr 09, 2011 at 11:21:39AM -0400, Hal Rosenstock wrote:
> >>
> >> Add error field like errno to ib_rpc_t structure
> >> In mad_rpc code, make sure error is cleared and
> >> in _do_madrpc, set ETIMEDOUT.
> >>
> >> error field could also be used to distinguish other errors if needed.
> > 
> > This looks like it breaks the ABI since callers using functions that
> > accept ib_rpc_t are expected to allocate the ib_rpc_t struct
> > themselves.
> 
> Yes, this changes the ABI. I didn't see a good way not to do this. Do
> you have any ideas ? The only possible approach I saw was to steal the
> high order bit from mgtclass (class is really only a byte) to indicate
> which version of ib_rpc_t is being passed as to whether this field is
> present.

If you are going to change the ABI like this then you have to bump the
SONAME.

Setting a flag would work.

Jason
--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html