> 1. Section 11.2.1.2 -- Query HCA: > • The maximum number of scatter/gather entries per Work Re- > quest supported by this HCA, for all Work Requests other > than Reliable Datagram Receive Queue Work Requests. > > This certainly implies that the create verb should not return > a number of scatter-gather entries greater than the max_sge value > (which is the max value supported by this HCA).
I take this to mean that Query HCA should return the maxium number of s/g entries supported for all work requests (leaving aside RD). In other words, if some work requests support 4 s/g entries and others support 8, then query HCA should return 4 as the max s/g entries, since this is the largest number that *all* work requests support (although some support 8). > Otherwise, why have a max_sge value returned by Query HCA? What use > would it serve? It gives an upper bound on what consumers can request in a simple way, without having to have the complexity of per-transport limits for send and receive queues separately. > Furthermore, how can the HCA return an sge value > in Create QP which exceeds the max_sge value returned by Query HCA? If > it does, the sge value in Create QP should be the one returned in > Query HCA! The mlx4 case is a simple example: send work requests support more s/g entries than receive work requests do. So query HCA must return the lower receive work request limit, but I see no reason why create QP can't return the actual limit for send work requests. - R. _______________________________________________ general mailing list [email protected] http://lists.openfabrics.org/cgi-bin/mailman/listinfo/general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
