- Add new flag UBC_ISMAPPED which tells ubc_uiomove() the object is mmap()ed
somewhere. Use it to decide whether to do direct-mapped copy, rather than
poking around directly in the vnode in ubc_uiomove(), which is ugly and
doesn't work for tmpfs. It would be nicer to contain all this in UVM but
the filesystem provides the needed locking here (VV_MAPPED) and to
reinvent that would suck more.
- Rename UBC_UNMAP_FLAG() to UBC_VNODE_FLAGS(). Pass in UBC_ISMAPPED where
appropriate.
and getcwd():
- push vnode locking back as far as possible.
- do most lookups directly in the namecache, avoiding vnode locks & refs.
- don't block new refs to vnodes across VOP_INACTIVE().
- get shared locks for VOP_LOOKUP() if the file system supports it.
- correct lock types for VOP_ACCESS() / VOP_GETATTR() in a few places.
Possible future enhancements:
- make the lookups lockless.
- support dotdot lookups by being lockless and inferring absence of chroot.
- maybe make it work for layered file systems.
- avoid vnode references at the root & cwd.
automate installation of sysctl nodes.
Note that there are still a number of device and pseudo-device modules
that create entries tied to individual device units, rather than to the
module itself. These are not changed.
has been deleted. Otherwise VFS will try to write cached data "back to
disc", which in the case of a UAO means needless page deactivations and
the resulting TLB shootdowns.
This did not do what I thought it did. opt_diagnostic.h is only for
the unused _DIAGNOSTIC, which seems like an abortive attempt to
incrementally convert DIAGNOSTIC to an opt_*.h option rather than a
command-line option.
- Change the lock on uvm_object, vm_amap and vm_anon to be a RW lock.
- Break v_interlock and vmobjlock apart. v_interlock remains a mutex.
- Do partial PV list locking in the x86 pmap. Others to follow later.
without any synchronization against changes by e.g. clock_settime().
- Replace with new getbinboottime() / getnanoboottime() / getmicroboottime()
functions (naming mirrors that of other time access functions in kern_tc.c).
It returns the (maybe-converted) value of timebasebin, which also tracks
our estimate of when the system was booted (i.e. the legacy "boottime" was
redundant).
XXX There needs to be a lockless synchronization mechanism for reading
timebasebin, but this is a problem in kern_tc.c that pre-existed these
"boottime" changes. At least now the problem is centralized in one location.
module hook, we can share a common set of synchronization structures.
This cuts the amount of cacheline_aligned data for these structures by
50%.
Note that we still have a per-hook localcount, since we need to count
individual references.
As discussed with riastradh@
Welcome to 9.99.22 !
tkusumi