Krishna Kumar2 wrote:

quoted

Herbert Xu [off-list ref] wrote on 01/29/2010 02:36:25 PM:

quoted

I ran 5 serial netperf's with 16K and another 5 serial netperfs
with 64K I/O sizes, and the aggregate result is:

0. Driver unsets F_SG but sets F_GSO:
     Original code with 16K: 19471.65
     New code with 16K:      19409.70
     Original code with 64K: 21357.23
     New code with 64K:      22050.42

OK this is more in line with what I was expecting, namely that
enabling GSO is actually beneficial even without SG.

It would be good to get the CPU utilisation figures so we can
see the complete picture.

Same 5 runs of single netperf's:

0. Driver unsets F_SG but sets F_GSO:
        Org (16K):      BW: 18180.71    SD: 13.485
        New (16K):      BW: 18113.15    SD: 13.551
        Org (64K):      BW: 21980.28    SD: 10.306
        New (64K):      BW: 21386.59    SD: 10.447

1. Driver unsets F_SG, and with GSO off
        Org (16K):      BW: 10894.62    SD: 26.591
        New (16K):      BW: 7262.10     SD: 35.340
        Org (64K):      BW: 12396.41    SD: 23.357
        New (64K):      BW: 7853.02     SD: 32.405


2. Driver unsets F_SG and uses ethtool to set GSO:
        Org (16K):      BW: 18094.11    SD: 13.603
        New (16K):      BW: 17952.38    SD: 13.743
        Org (64K):      BW: 21540.78    SD: 10.771
        New (64K):      BW: 21818.35    SD: 10.598

Just a slight change in service demand there...  For those unfamiliar, 
service demand in netperf is the microseconds of non-idle CPU time per 
KB of data transferred.  Smaller is better.

happy benchmarking,

rick jones