On Tue, 2016-12-06 at 16:35 +0000, Harris, James R wrote:
> 
> > On Dec 6, 2016, at 5:49 AM, Kumaraparameshwaran Rathnavel <krath(a)cloudsimple
> > .com> wrote:
> > 
> > The setup is the default setup of NVMf target with Direct attached
> > Subsystem. The FIO plugin was at the target side and the IOPS from SPDK was
> > found to be around 2.5K and the IOPS from kernel was found to be 100k.
> 
> 
> Hi Param,
> 
> Can you check the AcceptorPollRate setting in your configuration file?  There
> was a recent fix to the default value for this parameter.  You should set it
> to at least 10000 (10ms).
> 
> https://github.com/spdk/spdk/commit/5f3761cf7ec50cf03183203dc50657a9f2a18908
> 
> Thanks,

Just to reinforce here - this is the solution. We saw this internally a few
weeks ago. Increasing the AcceptorPollRate to at least 10ms (you can go as much
as 1 second if you want, but the performance benefit decreases the larger you
make it), or moving the accceptor to a different core using the AcceptorCore
option will fix the problem.

> 
> -Jim
> 
> > 
> > Regards,
> > Param.
> > > On 06-Dec-2016, at 5:57 PM, Andrey Kuzmin <andrey.v.kuzmin(a)gmail.com>
> > > wrote:
> > > 
> > > 
> > > 
> > > On Tue, Dec 6, 2016, 15:24 Kumaraparameshwaran Rathnavel <krath(a)cloudsimpl
> > > e.com> wrote:
> > > > Hi All,
> > > > 
> > > > Is there any benchmarking done to prove that SPDK is better than the
> > > > Kernel driver?
> > > > 
> > > > We did run the sample driver provided from the SPDK and compared with
> > > > the kernel interface and found that SPDK is very slow. We did run FIO.
> > > > 
> > > 
> > > It's worth publishing your setup and results first.
> > > 
> > > Regards,
> > > Andrey
> > > > 
> > > > Can you describe the setup for the performance measurement between
> > > > Kernel and SPDK driver.
> > > > 
> > > > Regards,
> > > > Param.
> > > > _______________________________________________
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> > > > SPDK(a)lists.01.org
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> > > > 
> > > -- 
> > > Regards,
> > > Andrey
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> > 
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