> -----Original Message----- > From: Jason Gunthorpe [mailto:jgunthorpe@xxxxxxxxxxxxxxxxxxxx] > Sent: Tuesday, July 25, 2017 4:34 PM > To: Steve Wise > Cc: linux-rdma@xxxxxxxxxxxxxxx; 'Doug Ledford'; 'Ram Amrani'; 'Ira Weiny'; > 'Benjamin Drung'; 'Jarod Wilson' > Subject: Re: [PATCH rdma-core 0/5] Common systemd/udev based boot support > > On Tue, Jul 25, 2017 at 01:49:37PM -0500, Steve Wise wrote: > > > After I rebooted, cxgb4 and iw_cxgb4 were loaded, but the services were not > > started. I think that is probably due to the fact that iw_cxgb4 doesn't > > register with the rdma core until the cxgb4 interfaces are brought > > up. > > Yes, it is done on demand when the kernel creates its side of the > interface. > > > I then brought up port 0 of the cxgb4 card: > > > > [root@stevo3 ~]# ip link set enp4s0f4 up > > [root@stevo3 ~]# ip addr add 172.16.3.3/24 dev enp4s0f4 > > > > And then the services were started: > > Yep, everything you sent me looks fine, thanks for taking a look at > this. > Great! You can add a Tested-by: line for me. > This sort of hotplug that cxbg4 does is quite strange, what happens > when 'ip link set X down' is done? Does it remove the RDMA device? > Does 'ip link set down' block until all users go away? > No. iw_cxgb4 just triggers on the first 'up', to add the rdma provider instance for that device. The Low Level Driver (LLD), cxgb4, passes the CXGB4_STATE_UP event to all registered upper level drivers (ULDs) when the first port is enabled (see cxgb_up). Any rdma connections that are active when a link goes down still function, as any TCP connection would function if the interface was brought down; eg: tcp retransmits if there is pending data until it gives up and aborts the connection. So Netdev link down/up transitions are hidden from the rdma application. > This is going to make it harder for cxgb users to get a reliably > bootup at this time, we need more kernel autoloading for things to be > reliable, and I'm sure iwpmd.service needs some dependency adjusting, > I just don't know enough about it to do it right. :\ I don't understand? Stevo -- 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
