Re: [PATCH trivial] UAPI: Kbuild: add/modify comments for "uapi/Kbuild" and "uapi/linux/Kbuild"

[Chen Gang <gang.chen@asianux.com>]

On 09/04/2013 05:27 PM, Geert Uytterhoeven wrote:
> On Wed, Sep 4, 2013 at 11:13 AM, Chen Gang <gang.chen@asianux.com> wrote:
>>>> Hmm... why we need "uapi/linux/" ?  (I can not find some related
>>>> documents, so I have to 'guess').
>>>
>>> The "uapi" subdirectories are there to distinguish userspace headers from
>>> kernelspace headers, and allow both to live in the kernel source tree.
>>>
>>> When running "make headers_install", the (processed) headers in the
>>> various "uapi" subdirectories are copied to /usr/include.
>>> Hence "uapi/linux/foo.h" becomes <linux/foo.h> in userspace.
>>> In userspace there are no "uapi" subdirectories anymore.
>>>
>>
>> Yeah, so why need another "uapi/*" excluding "uapi/linux" ?
>>
>> Are they also truly still "Userspace API" but which need not distinguish
>> ? (at least, it seems that idea is not quite good).
>>
>> Hmm... maybe the "uapi/*" except "uapi/linux" are also installed? Is it
>> for compatible (originally they are here, and now we have to follow, it
>> is no reason to change if not find related critical issues)?
> 
> All uapi files are installed, a.o. /usr/include/scsi/, /usr/include/video/, ...
> 

Oh, sorry, I misunderstand your original mail contents.

> Historically, everything under "include" in the kernel source tree was
> installed in /usr/include/, after (semi)manual cleanup.
> Since the uapi split, everything is handled automatically.
> Because of compatibility reasons (do not break userspace), paths had to
> stay the same.
> 

At least for me, that sounds reasonable.

Hmm... when some members need add a new Userspace API. I guess:

  if it is related with one of existent "uapi/*" sub-directory (except "uapi/linux"), they need put the file(or directory) under the related "uapi/*",

  if can not find existent "uapi/*" sub-directory, they need put the file(or directory) under "uapi/linux/*".

Does it sound reasonable ?


Thanks.

> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds
> 
> 


-- 
Chen Gang