> From: Arlin Davis [mailto:[EMAIL PROTECTED] > Sent: Thursday, October 13, 2005 9:42 AM > > Sean Hefty wrote: > > > Arlin Davis wrote: > > > >> I just noticed some RDMA read performance issues that seem to be > >> related to the QP starting sequence number. If I set the starting > >> sequence to 1 then all is fine but if I set it to 0x10000 then it > >> seems to add ~40us to my 32KB RDMA read operation (polling for > >> completions). Has anyone seen anything like this? > > > > > > Has anyone else noticed this issue? You could try to reproduce this > > by using the rdma_bw test and changing the PSN. > > > > - Sean > > > > I added a starting PSN and RDMA READ option to the rdma_bw test and was > able to reproduce on a PCI-E adapter with 4.6.2 firmware. I retried on a > system with 4.7.0 and it looks like the problem is fixed. However, I > see nothing about this problem in the "bug fix" list in the release > notes. Can someone at Mellanox confirm this problem with RDMA reads and > add to release notes as a fix so it is documented somewhere? > > http://www.mellanox.com/products/fw_images/fw-25208-4_7_0-release_notes.pdf
Note that I have seen similar behavior (drop in bandwidth) correlated to starting PSN using Winsock Direct under Windows, so this doesn't seem to be a uDAPL or Linux issue. As for Arlin, the issue disappeared in firmware 4.7.0, and I too would like to see some confirmation that there was an issue and that it was fixed. Thanks, - Fab _______________________________________________ openib-general mailing list [email protected] http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
