Messages in this thread | | | Date | Tue, 12 Nov 2013 09:03:14 +0800 | Subject | Re: Got iperf regression while intel_iommu is on, how to cut the cost of cache flushing | From | Ethan Zhao <> |
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Eric, We have tested the performance with the TSO and TSQ patches merged, the result not good, even worse than kernel without those two patches. any idea ?
kernel : 3.11.x with TSO & TSQ merged. ( CONFIG_INTEL_IOMMU_DEFAULT_ON=y ) Network Interface : eth4 Network driver : be2net
Average Bandwidth for : 1.tcp-unidirectional test : 4385 Mbits/sec 2.tcp-unidirectional-parallel: 9383 Mbits/sec 3.tcp-bidirectonal test : 2755 Mbits/sec
vs
kernel : 3.11.x without TSO & TSQ patches. (CONFIG_INTEL_IOMMU_DEFAULT_ON is not set) Network Interface : eth4 Network driver : be2net
Average Bandwidth for : 1.tcp-unidirectional test : 7992 Mbits/sec 2.tcp-unidirectional-parallel: 9403 Mbits/sec 3.tcp-bidirectonal test : 5802 Mbits/sec
Thanks, Ethan
On Thu, Oct 31, 2013 at 11:25 PM, Eric Dumazet <eric.dumazet@gmail.com> wrote: > 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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