dillon at apollo.backplane.com
Sun Apr 23 00:16:18 PDT 2006
Well, I would say that nothing has been abandoned, but these items need
developer hands for progress to take place and I am only one person.
There are a lot of people working the edges (and this is very necessary
in order for DragonFly to remain viable), but only a handful of people
doing big ticket items. Users have different needs and, unfortunately,
it is not possible to make all of them priority #1.
My focus is squarely on the critical path, which I outlined at the
beginning of the year: A cache coherency model that works well
enough to be able to migrate execution contexts between machines,
a userland VFS interface (primarily so ZFS can be ported in userland
== more developer hands available to help out), and other issues related
to supporting clustering.
Laying the groundwork for this is itself a huge task. It's pretty much
all I have been doing for the last two years. For example, userland
VFS is impractical without a VFS API that is capable of breaking UIO's
up into buffer-sized segments, or without direct buffer cache access
above the VFS layer for it to be efficient. To do cache coherency right
we need a ranged locking layer (actually several layers), which means
that the entire I/O subsystem had to be converted to a byte-oriented
API from a block oriented API. In fact, we have to get rid of global
vnode locks entirely, which will not be easy. Its a huge list.
AMD64 is desireable, as is more SMP work, and I'd be quite happy if
other developers did some work in those areas. Not to mention keeping
device drivers up to date. But I could spend my entire life doing
nothing but device drivers and have nothing truely innovative or
interesting to show for it at the end of that road. So despite its
importance it would be a very bad move for me to drop everything and
focus on driver maintainance. I have to prioritize my own work and right
now that priority is on cache coherency and cluster-related code.
The edge work keeps us within shouting distance of all our goals, but
the large scale pushes are necessarily going to be far more narrowly
If you want to help out then choose something near and dear to your heart
and start working on it. My only caution is that large scale endevours
must be done in committable bite-sized chunks. Trying to do something
like AMD64 in one big patch, for example, would only result in an
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