Use the dedicated reference counting routines.
Change the type of struct vmspace::vm_refcnt and struct vm_map::ref_count
to volatile.
Remove the unnecessary vm->vm_map.misc_lock locking in process_domem().
Reviewed by <ad>
pmap is emptied. Pass UVM_FLAG_VAONLY when clearing out the map and avoid
needless extra work to tear down each mapping individually.
- uvm_map_lookup_entry(): remove the code to do a linear scan of map entries
for small maps, in preference to using the RB tree. It's questionable,
and I think the code is almost never triggered because the average number
of map entries has probably exceeded the hard-coded threshold for quite
some time.
- vm_map_entry: get it aligned on a cacheline boundary, and cluster fields
used during rbtree lookup at the beginning.
- 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.
mprotect settings so that debuggers can write to the text segment of traced
processes so that they can insert breakpoints. Turned off by default.
Ok: chuq (for now)
simplifying uvm_map handling (no special kernel entries anymore no relocking)
make malloc(9) a thin wrapper around kmem(9)
(with private interface for interrupt safety reasons)
releng@ acknowledged
- 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.
ambiguous members ownspace/space to gap/maxgap. Add some evcnt for
evaluation of lookups using tree/list. Drop threshold of using
tree for lookups from > 30 to > 15.
Bump kernel version to 4.99.71
- don't use managed mappings/backing objects for wired memory allocations.
save some resources like pv_entry. also fix (most of) PR/27030.
- simplify kernel memory management API.
- simplify pmap bootstrap of some ports.
- some related cleanups.
define and use vm_map_set{min,max}() for modifying these values.
remove the {min,max}_offset aliases for these vm_map fields to be more
namespace-friendly. PR 26475.
- allocate kva for vm_map_entry from the map itsself and
remove the static limit, MAX_KMAPENT.
- keep merged entries for later splitting to fix allocate-to-free problem.
PR/24039.
- for in-kernel maps, disable map entry merging so that
unmap operations won't block. (workaround for PR/24039)
- for in-kernel maps, allocate kva for vm_map_entry from
the map itsself and eliminate MAX_KMAPENT and
uvm_map_entry_kmem_pool.
to improve scalability of operations on the map.
originally done by Niels Provos for OpenBSD.
tweaked for NetBSD by me with some advices from enami tsugutomo.
discussed on tech-kern@ and tech-perform@.
means that the dynamic linker gets mapped in at the top of available
user virtual memory (typically just below the stack), shared libraries
get mapped downwards from that point, and calls to mmap() that don't
specify a preferred address will get mapped in below those.
This means that the heap and the mmap()ed allocations will grow
towards each other, allowing one or the other to grow larger than
before. Previously, the heap was limited to MAXDSIZ by the placement
of the dynamic linker (and the process's rlimits) and the space
available to mmap was hobbled by this reservation.
This is currently only enabled via an *option* for the i386 platform
(though other platforms are expected to follow). Add "options
USE_TOPDOWN_VM" to your kernel config file, rerun config, and rebuild
your kernel to take advantage of this.
Note that the pmap_prefer() interface has not yet been modified to
play nicely with this, so those platforms require a bit more work
(most notably the sparc) before they can use this new memory
arrangement.
This change also introduces a VM_DEFAULT_ADDRESS() macro that picks
the appropriate default address based on the size of the allocation or
the size of the process's text segment accordingly. Several drivers
and the SYSV SHM address assignment were changed to use this instead
of each one picking their own "default".
tearing down a vm_map. use this to skip the pmap_update()
at the end of all the removes, which allows pmaps to optimize
pmap tear-down. also, use the new pmap_remove_all() hook to
let the pmap implemenation know what we're up to.
kamil