Re: Path to kmods

[Joerg Sonnenberger <joerg%britannica.bec.de@localhost>]

On Sat, Nov 22, 2008 at 03:00:36PM -0500, Martin S. Weber wrote:
> Who fixes softdeps? "It is going to be dropped and replaced
> by WAPBL".

I will pick this specific item as it is one of the things I am involved
with. First of all, what is the problem with softdeps? It is a huge
amount of code, it is complicating the whole FFS code and it is
complicating the rest of the buffer code as well. In short, the softdep
code as it is is very intrusive. It gives little to no advantage over a
*working* WAPBL. Note that I don't say that WAPBL is correctly working
right now, it has issues. Softdep due to its very nature depends on IO
ordering contraints that are not available at least for consumer hard
disks without completely killing performance and it will break in ways
that are not obvious. So -- who might want to fix softdeps? Look at the
code first. Do you want to provide patches? Do you want to compensate
people for the pain needed to fix problems? Will you compensate people
for effectively wasting time on a to-be-redundant feature just because
it was once supported? It won't be dropped until WAPBL can hold up to
the promises made.

Joerg