ZFS_DEBUG + enable ZFS ASSERTS with INVARIANTS any objections?

[Andriy Gapon]

on 02/07/2013 09:51 Matthew Ahrens said the following:
> If I understand correctly, INVARIANTS is a mechanism that enables
> additional runtime checks in the kernel, analogous to DEBUG enabling
> ASSERTions in Solaris-derived code.

Yes.

> You want to turn on ZFS_DEBUG and
> assertions within ZFS without setting DEBUG in general.
> 
> Why do you want to do this?

Because in larger FreeBSD kernel DEBUG has already been used for other purposes.
 In some place it enables lots of printfs that typically are of no interest but
can easily spam logs / message buffer.

> Why not set DEBUG and turn on all assertions
> in Solaris-derived code?  If it is performance, how much slow down do
> non-ZFS assertions cause?  If it's too much, can we fix that?
> 
> I'm not sure why ZFS_DEBUG exists, rather than just using DEBUG.  It may be
> historical; now it seems that ZFS_DEBUG and DEBUG are always set together
> (including in libzpool).  Unless there's a good reason for them to be
> separate, I'd rather see ZFS_DEBUG removed, and use DEBUG instead.



-- 
Andriy Gapon