On Mon, Oct 20, 2014 at 6:29 PM, Chris Moore <Chris.Moore@xxxxxxxxxx> wrote: > The following code is in isert_conn_setup_qp() in ib_isert.c: > > /* > * FIXME: Use devattr.max_sge - 2 for max_send_sge as > * work-around for RDMA_READ.. > */ > attr.cap.max_send_sge = device->dev_attr.max_sge - 2; > > It's not clear from the comment what this is a work-around for, and I wasn't able > to figure it out from looking at logs. I believe this refers to some IBTA spec corner case which comes into play with the max_sges advertized by mlx4, Eli, can you shed some light (IBTA pointer) on that? is this the case (i.e dev_attr.max_sge isn't always achievable) with mlx5 too? > In trying to get isert working with ocrdma I ran into a problem where the code > thought there was only 1 send SGE available when in fact the device has 3. > Then I found the above work-around, which explained the problem. Nic, any reason for attr.cap.max_send_sge = 1 not to work OK? > Removing this (setting attr.cap.max_send_sge to device->dev_attr.max_sge) > fixes the problem with isert and ocrdma, but I don't know what other side effects > that might have. > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
