The good news is that I suspect they are going away. It probably is mainly
tty and /proc by now, and /proc is pretty close to done.
It's hard to have too many inter-module dependencies when most of the core
modules no longer even take the kernel lock any more.
In the VFS layer, we still have
- the ioctl thing, obviously. That's just mind-numbing "move things
down", not hard per se. But there's a *lot* of them (and I suspect the
huge majority of them don't actually need it, since they'd already be
racing against read/write anyway if they did).
- default_llseek(). Probably the same, just a lot less of it.
- superblock read/write.
and the latter one in particular is really dubious (we already have
"[un]lock_super()" around it all, I think).
The core kernel, VM and networking already don't really do BKL. And it's
seldom the case that subsystems interact with other unrelated subsystems
outside of the core areas.
So it's a lot of work, no doubt, but I do think we should be able to do
it. The most mind-numbing part is literally all the ioctl crud. There's
more ioctl points than there are lock_kernel() calls left anywhere else.
Linus
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