Messages in this thread |  | | Subject | Re: Got iperf regression while intel_iommu is on, how to cut the cost of cache flushing | From | Eric Dumazet <> | Date | Thu, 31 Oct 2013 08:25:36 -0700 |
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On Thu, 2013-10-31 at 10:44 +0800, Ethan Zhao wrote: > Hi guys, > > We got network I/O performance degradation with latest stable > kernel and the be2net driver as compared to old kernel 3.0.6. later > we found even compared to > the same latest stable kernel but the INTEL_IOMMU set to 'n', still > got very noticeable performance regression: > > Kernel : 3.11.x with CONFIG_INTEL_IOMMU_DEFAULT_ON not set > Network driver : be2net > > Average Bandwidth for : > 1.tcp-unidirectional test : 7908 Mbits/sec > 2.tcp-unidirectional-parallel: 9400 Mbits/sec > 3.tcp-bidirectonal test : 5464 Mbits/sec > > Kernel : 3.11.x with CONFIG_INTEL_IOMMU_DEFAULT_ON set > Network driver : be2net
You might hit a known problem for some 10Gb links.
3.12-rc6 has the fixes already, and stable has some pending backports :
commit 95bd09eb27507691520d39ee1044d6ad831c1168 tcp: TSO packets automatic sizing
commit c9eeec26e32e087359160406f96e0949b3cc6f10 tcp: TSQ can use a dynamic limit
Please check that current 3.12-rc6 is OK ?
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