Re: [Xenomai-core] [RFC 0/1] Class driver for raw Ethernet packets

[Jan Kiszka <jan.kiszka@domain.hid>]

On 2011-09-27 19:04, Richard Cochran wrote:
> On Tue, Sep 27, 2011 at 06:30:00PM +0200, Jan Kiszka wrote:
>> On 2011-09-27 18:26, Jan Kiszka wrote:
>>> I was simply hoping to collect some new ideas how to address the driver
>>> maintenance issue in a better way but without dropping key features
>>> needed for RT networking. Something like "let's add generic RT channels
>>> to Linux upstream drivers and then only patch them fit RTDM". Not sure
>>> if that works, but it would come with a vision how to keep things more
>>> maintainable.
>>
>> +this could be useful for other scenarios - on PREEMPT-RT.
> 
> (But PREEMPT-RT will make the whole kernel deterministic, right? ;)

Yes. Except where not.

> 
> Adding low-latency channels (eg. working against coalescing) will be a
> very hard sell upstream.

That also depends on the invasiveness. Key requirements like separate
packet pools slowly sneak in (for swap over net). Also, separate IRQs
for separate channels on modern NICs may make the split-out smoother -
you may no longer need to disable features that used to affect the same
handler or shared some locks.

Jan

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