This uglifies the interface, because several operations need to be
passed the namei flags and cache_lookup also needs for the time being
to be passed cnp->cn_nameiop. Nonetheless, it's a net benefit.
The glop should be able to go away eventually but requires structural
cleanup elsewhere first.
This change requires a kernel bump.
- Reorganize locking in UVM and provide extra serialisation for pmap(9).
New lock order: [vmpage-owner-lock] -> pmap-lock.
- Simplify locking in some pmap(9) modules by removing P->V locking.
- Use lock object on vmobjlock (and thus vnode_t::v_interlock) to share
the locks amongst UVM objects where necessary (tmpfs, layerfs, unionfs).
- Rewrite and optimise x86 TLB shootdown code, make it simpler and cleaner.
Add TLBSTATS option for x86 to collect statistics about TLB shootdowns.
- Unify /dev/mem et al in MI code and provide required locking (removes
kernel-lock on some ports). Also, avoid cache-aliasing issues.
Thanks to Andrew Doran and Joerg Sonnenberger, as their initial patches
formed the core changes of this branch.
- VOP_LOCK(vp, flags): Limit the set of allowed flags to LK_EXCLUSIVE,
LK_SHARED and LK_NOWAIT. LK_INTERLOCK is no longer allowed as it
makes no sense here.
- VOP_ISLOCKED(vp): Remove the for some time unused return value
LK_EXCLOTHER. Mark this operation as "diagnostic only".
Making a lock decision based on this operation is no longer allowed.
Discussed on tech-kern.
