[openib-general] Timeline of IPoIB performance

[Matt Leininger]

I'm seeing an IPoIB netperf performance drop off, up to 90 MB/s, when
using kernels newer than 2.6.11.  This doesn't appear to be an OpenIB
IPoIB issue since the in-kernel and a recent svn3687 snapshot both have
the same performance (464 MB/s) with 2.6.11.  I used the same kernel
config file as a starting point for each of these kernel builds.  Have
there been any changes in Linux that would explain these results?


All benchmarks are with RHEL4 x86_64 with HCA FW v4.7.0
dual EM64T 3.2 GHz PCIe IB HCA (memfull)

Kernel           OpenIB    msi_x  netperf (MB/s)  
2.6.14-rc3      in-kernel    1     374 
2.6.13.2        svn3627      1     386 
2.6.13.2        in-kernel    1     394 
2.6.12          in-kernel    1     406 
2.6.11          in-kernel    1     464 
2.6.11          svn3687      1     464 
2.6.9-11.ELsmp  svn3513      1     425  (Woody's results, 3.6Ghz EM64T) 

  Thanks,

	- Matt