Re: add DIAGNOSTIC back to GENERIC/INSTALL

[Mindaugas Rasiukevicius <rmind%netbsd.org@localhost>]

Mindaugas Rasiukevicius <rmind%netbsd.org@localhost> wrote:
> I have few concerns:
> 
> - If we enable DIAGNOSTIC, then we should also enable DEBUG, as it also
>   covers many relevant diagnostic checks.
> 
> - Alternatively, it should be clearly defined what goes under DEBUG,
>   i.e. what is considered a "heavier check".  I think code diverged in
>   a way that the difference between DEBUG and DIAGNOSTIC is small.
> 
> - Since performance is degraded and -current users concerned about it
>   will need to compile their own kernels anyway - I believe LOCKDEBUG
>   should be enabled as well.  Perhaps LOCKDEBUG should become a part
>   of DEBUG - it is at least clearly a "heavier check". :)
> 
> - There MUST be a very clear indication to users - a warning in a visible
>   place that the kernel has diagnostic options enabled, and performance
>   is significantly degraded.
> 
> - Obviously, defined policy/responsibility to disable these options for
>   release kernels.  In fact, if we go this way - then options should be
>   removed from all MD kernel configs and managed in MI src/sys/conf/std.

- DDB_ONPANIC=1 and DDB_COMMANDONENTER="bt;show regsisters" and perhaps
  also "call ddb_vgapost" in the beginning (not sure if there are any
  potential side effects?).  Otherwise, not getting information from DDB
  is just counter-productive, plus we get not very useful reports, when
  backtrace is missing.

-- 
Mindaugas