Re: [dpdk-dev] i40e: Steps and required configurations of how to achieve the best performance!

["Zhang, Helin" <helin.zhang@intel.com>]

Hi Thomas

Yes, your proposal it the perfect one, also the most complicated one. I was thinking of that one as well, but we did not have enough time for that in our 1.8 timeframe.
In the long run, I agree with you to implement EAL function to access PCI config space directly. I will try to put it in our plan as soon as possible, if no objections.

For now, I think the quickest and easiest way might be to write out a script of using ‘setpci’, the Linux command. It is harmless for our code base, and we can remove it when we have better choice. What do you think?

Thank you very much for the great comments on this topic! I really like it!

Regards,
Helin

From: Thomas Monjalon [mailto:thomas.monjalon@6wind.com]
Sent: Wednesday, October 15, 2014 5:42 PM
To: Zhang, Helin
Cc: dev@dpdk.org; David Marchand
Subject: Re: [dpdk-dev] i40e: Steps and required configurations of how to achieve the best performance!


Hi Helin,



2014-09-19 03:43, Zhang, Helin:

> My idea on it could be,

> 1. Write a script to use ‘setpci’ to configure pci configuration.

> End user can decide which PCI device needs to be changed.

> 2. Add code to change that PCI configuration in i40e PMD only, as

> it seems nobody else need it till now.



The second solution seems better because more integrated and automatic.

But I would like to have some EAL functions to access to PCI configuration.

These functions would have Linux and BSD implementations.

Then the PMD could change the configuration if it's allowed by a run-time

option and would notify the change with a warning/log.



Thanks for keeping us notified of your progress.

--

Thomas