Re: [Xenomai-help] [Fwd: Performance decrease]

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

[-- Attachment #1: Type: text/plain, Size: 1398 bytes --]

Daniel Schnell wrote:
> Hi,
> 
> 
>>>> For what is the real-time support in user space option good for ?
>>>>
>> This allows running Xenomai applications in user-space, instead of
>> implementing them as kernel modules.
>>
> 
> Everyone planning to write kernel-space drivers and/or applications
> should keep an eye on some non-technical aspect as well: the license.
> That's no problem for in-house, unpublished work. But for things that
> are to be given away / sold, one should recall that the kernel community
> is more and more considering non-GPL modules in general as a license
> infringement.
> 
> 
> Hmm, if I am writing an application that uses Xenomai's magic, e.g. in
> using the POSIX API, that shouldn't violate any GPL code isn't it ? Of
> course a kernel module should be GPL, because it is linked to the GPL
> kernel.

Well, kernel developers have a standard answer: "Consult a lawyer." And
if you are really going for a non-GPL kernel-based product, this is
probably a good idea to assess potential risks. Note that the Xenomai
API in kernel space is GPL due to the GPL environment of the kernel.
Only the user-space libs are LGPL.

> 
> So are RTDM drivers principially running in user space then ?

RTDM drivers are currently running in kernel space only, but they are
providing services to both user and kernel space, symmetrically.

Jan


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 250 bytes --]