Re: [dpdk-dev] [PATCH v3] doc: add performance test guide to the linux gsg

["Xu, Qian Q" <qian.q.xu@intel.com>]

Thomas
Thanks for the comments. See my comments inline below. Let me know if you have objections, if no, I will send a v4 patch soon. 

Thanks
Qian

-----Original Message-----
From: Thomas Monjalon [mailto:thomas.monjalon@6wind.com] 
Sent: Friday, September 25, 2015 10:11 PM
To: Xu, Qian Q
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v3] doc: add performance test guide to the linux gsg

2015-09-24 19:48, Qian Xu:
> --- a/doc/guides/linux_gsg/index.rst
> +++ b/doc/guides/linux_gsg/index.rst
> @@ -47,3 +47,4 @@ Contents
>      build_sample_apps
>      enable_func
>      quick_start
> +    perf_test_intel_platform_nic

Why "test"? What about nic_perf_intel_platform?
[Qian] OK. 

> --- /dev/null
> +++ b/doc/guides/linux_gsg/perf_test_intel_platform_nic.rst
[...]
> +Grub Boot Parameters
> +~~~~~~~~~~~~~~~~~~~~
> +
> +The following are some recommendations on GRUB boot settings:
> +
> +#. Use the default grub file as a starting point.
> +
> +#. Reserve 1G huge pages via grub configurations. For example to reserve 8 huge pages of 1G size::
> +
> +      default_hugepagesz=1G hugepagesz=1G hugepages=8
> +
> +#. Isolate CPU cores which will be used for DPDK. For example::
> +
> +      isolcpus=2,3,4,5,6,7,8
> +
> +#. If it wants to use VFIO, use the following additional grub parameters::
> +
> +      iommu=pt intel_iommu=on

These paramters can be set with GRUB, yes.
But they are Linux command line parameters.
I suggest to change the title.
[Qian] OK. 
[...]
> +4. Bind the test ports to igb_uio. For example bind two ports to a DPDK compatible driver and check the status:

Not speaking about VFIO here suggests that igb_uio gives better performance.
By the way, UIO/VFIO is not used by mlx4.
[Qian] In fact not suggests a better performance with igb_uio, but as to VFIO, we need to turn on VT-d in the BIOS, it's an additional step. So here I want to change it as "UIO(e.g: igb_uio) or VFIO(turn on VT-d in the BIOS)", not sure mlx4 uses which module for dpdk running. 
[...]
> +   Note: Don't use one 2 lcores on the same core

one 2 lcores? looks to be a typo
[Qian] Will correct it.
[...]
> +5. As it is known that a XL710 40G port need at least two queue pairs to achieve best performance,

Is it well known? At least it is said here.
[Qian] Maybe well known only in Intel. I will change it as : A XL710 40G port need at least two queue pairs to achieve best performance. 

> +8. Configure the traffic to a traffic generator such as IXIA or Spirent.
> +
> +   * Start creating a stream on packet generator, e.g. IXIA.

Not sure mentioning IXIA or Spirent helps here.
Same comment for the (nice) diagram.
[Qian] *Start creating a stream on packet generator, usually hardware traffic generator can provide line rate traffic, so the NIC's best performance will not be limited by the traffic generator. Hardware traffic generator is like IXIA or Spirent. You can also use high speed software traffic generator to check the NIC's performance. 


Thanks for the documentation effort.