Jason Gunthorpe <[email protected]> wrote: >> Modify libmlx4 to support IBoE, where the only user space piece >> to handle is the creation of UD address handles - the L2 Ethernet >> attributes have to be resolved from the DGID.
> Other than rejecting some GIDs it doesn't seem like there is any > operational need to learn the link type.. Jason, as the change log explains, under Ethernet link type the code (see mlx4_resolve_grh_to_l2) goes and extracts the Ethernet L2 info (mac and vlan, look on the last patch) from the GID. > It seems a shame to add a kernel syscall to every ah creation just to learn > the link type AH creation is app's slow path, e.g the equivalent of session creation, so I wouldn't bother too much on perf, on the being elegant side, I'll check if/how I can plant/cache the link type for the ah creation code to use. > Also, did anyone document the GID format for IBoE? IIRC we invented > this for Linux since IBA refused to standardize anything. Not really, maybe we can/should add a document to the kernel IB documentation folder with some details - as this data is more for deep divers - the thing is that applications that use the rdma-cm don't deal directly with the GIDs, they just get it from the kernel and hand it over to libibverbs (e.g UD apps use address / route resolution and then call ah create, RC apps even don't have to call libibiverbs, as the qp modifications go beyond the cover of librdmacm calling libibverbs). Or. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
