Created attachment 406590 [details] some data Description of problem: The Niantic card has a performance regression when going from RHEL5.4 to RHEL5.5 On RHEL5.4 I see a throughput of app 9.3 Gbit/sec using a single stream netperf TCP_STREAM test with 16K message sizes. On RHEL5.5 on the same hardware, I see highly variable linespeeds. Also I'm observing that in RHEL5.5 the Niantic is running a lot slower on receive, (transmit is fine). The main symptom is a very "jerky" flow when running a single stream TCP_STREAM netperf test to the niantic. The thinking is that soemthing is filling up the queues and causing this behavior. If I use the modprobe option to create multiple vf, the issue goes away. It may be that this is related the RSC and flow director being bypassed in this mode. Also, reducing the coalesce time will improve the flow an throughput, although not entirely eliminate the issue. Version-Release number of selected component (if applicable): RHEL5.5 + ixgbe driver How reproducible: Always Steps to Reproduce: 1. Run netperf with large message sizes (./netperf -l 30 -H 172.17.20.22 -D ) 2. 3. Actual results: Very "jerky" flow and a low aggregate throughput. Expected results: Linespeed (9.4 Gbits/sec Additional info:
Created attachment 406612 [details] ixgbe-disable-multiple-tx-queues.patch Mark, one thing I've considered is that my backport may enable multiple TX queues in the driver on RHEL5.5 and if that is causing issues. Can you try this patch and let me know how it looks?
Tested that patch on Mark's system and found no benefit.
I have not been able to reproduce this issue. This is a test run from RHEL5.5 ia32e with the included ixgbe 2.0.44-k2 (2.6.18-194 kernel) #netperf -H u1505 -D TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to u1505 (190.0.15.5) port 0 AF_INET : demo Interim result: 9201.60 10^6bits/s over 1.00 seconds Interim result: 9251.12 10^6bits/s over 1.00 seconds Interim result: 9287.27 10^6bits/s over 1.00 seconds Interim result: 9270.80 10^6bits/s over 1.00 seconds Interim result: 9255.75 10^6bits/s over 1.00 seconds Interim result: 9281.18 10^6bits/s over 1.00 seconds Interim result: 9280.45 10^6bits/s over 1.00 seconds Interim result: 9284.71 10^6bits/s over 1.00 seconds Interim result: 9311.09 10^6bits/s over 1.00 seconds Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec Could you post the actual numbers you are seeing from the netperf run? Also the following information may be useful: - dmesg after loading the driver - cat /proc/interruts - lspci -vvv
data is included already included in an attachment to this (see near top of page) The other data you requested will take a while as the systems are in the midst of some RHEL6 work.
Mark, does it even make sense to keep this open at this point? It is on 5.5 and we are getting ready to ship 5.7. I'm going to close this as WORKSFORME, but we can reopen if needed.