Re: [dpdk-dev] [PATCH] Adding RTE_KNI_PREEMPT configuration option

[Marc Sune <marc.sune@bisdn.de>]

On 10/02/15 14:22, Bruce Richardson wrote:
> On Tue, Feb 10, 2015 at 01:21:55PM +0100, Marc Sune wrote:
>> On 10/02/15 13:02, Bruce Richardson wrote:
>>> On Tue, Feb 10, 2015 at 12:59:29PM +0100, Marc Sune wrote:
>>>> This patch of Nov 2014 hasn't been yet ACKed/NACKed. Could someone please
>>>> give some quick feedback?
>>>>
>>>> Thanks
>>>> marc
>>>>
>>> Idea is good, any chance it could be added as a run-time rather than
>>> compile-time option?
>> It is also an option. I wasn't really thinking someone would want to change
>> this behaviour at runtime. If we think it is worth, I can have a closer look
>> on it. Any other opinions on this?
>>
>> If we would go for a runtime flag, we would either have to add a config
>> parameter to rte_kni_init() or add a specific call to turn on/off this knob,
>> depending on whether it is sufficient to change this behaviour at
>> bootstrapping time, or we want to also change it during 'operation'. In
>> either case we would require some communication, probably via ioctl(), from
>> user-space to kernel space.
>>
>> Thanks
>> Marc
>>
> Yes, I can't see it needing to be changed much at runtime, however, we may need
> to take account of those who are using precompiled DPDK libs. For those using
> prebuilt DPDK libs, they won't have any ability to modify compile-time values.

I see the point. So it should be enough to improve rte_kni_init() with 
an extra argument, but this means add some additional ioctl() calls, as 
far as I see.

>
> However, that being said, I have no particular objection to taking this change
> in as-is for now. It only adds something, rather than taking it away.

Yes, we can improve it in the future, I have no time right now.

Thanks
marc

>
> Regards,
> /Bruce
>
>