vm_map_user_pageable().
o Remove vm_map_pageable() and vm_map_user_pageable().
o Remove vm_map_clear_recursive() and vm_map_set_recursive(). (They were
only used by vm_map_pageable() and vm_map_user_pageable().)
Reviewed by: tegge
Submitted by: tegge
o Eliminate the "!mapentzone" check from vm_map_entry_create() and
vm_map_entry_dispose(). Reviewed by: tegge
o Fix white-space usage in vm_map_entry_create().
or user vm_maps. This implementation has two key benefits when compared
to vm_map_{user_,}pageable(): (1) it avoids a race condition through
the use of "in-transition" vm_map entries and (2) it eliminates lock
recursion on the vm_map.
Note: there is still an error case that requires clean up.
Reviewed by: tegge
o Add a stub for vm_map_wire().
Note: the description of the previous commit had an error. The in-
transition flag actually blocks the deallocation of a vm_map_entry by
vm_map_delete() and vm_map_simplify_entry().
or user vm_maps. In accordance with the standards for munlock(2),
and in contrast to vm_map_user_pageable(), this implementation does not
allow holes in the specified region. This implementation uses the
"in transition" flag described below.
o Introduce a new flag, "in transition," to the vm_map_entry.
Eventually, vm_map_delete() and vm_map_simplify_entry() will respect
this flag by deallocating in-transition vm_map_entrys, allowing
the vm_map lock to be safely released in vm_map_unwire() and (the
forthcoming) vm_map_wire().
o Modify vm_map_simplify_entry() to respect the in-transition flag.
In collaboration with: tegge
vm_map_create(), and vm_map_submap().
o Make further use of a local variable in vm_map_entry_splay()
that caches a reference to one of a vm_map_entry's children.
(This reduces code size somewhat.)
o Revert a part of revision 1.66, deinlining vmspace_pmap().
(This function is MPSAFE.)
deinlining vm_map_entry_behavior() and vm_map_entry_set_behavior()
actually increases the kernel's size.
o Make vm_map_entry_set_behavior() static and add a comment describing
its purpose.
o Remove an unnecessary initialization statement from vm_map_entry_splay().
into the vm_object layer:
o Acquire and release Giant in vm_object_shadow() and
vm_object_page_remove().
o Remove the GIANT_REQUIRED assertion preceding vm_map_delete()'s call
to vm_object_page_remove().
o Remove the acquisition and release of Giant around vm_map_lookup()'s
call to vm_object_shadow().
and vm_map_delete(). Assert GIANT_REQUIRED in vm_map_delete()
only if operating on the kernel_object or the kmem_object.
o Remove GIANT_REQUIRED from vm_map_remove().
o Remove the acquisition and release of Giant from munmap().
the last accessed datum is moved to the root of the splay tree.
Therefore, on lookups in which the hint resulted in O(1) access,
the splay tree still achieves O(1) access. In contrast, on lookups
in which the hint failed miserably, the splay tree achieves amortized
logarithmic complexity, resulting in dramatic improvements on vm_maps
with a large number of entries. For example, the execution time
for replaying an access log from www.cs.rice.edu against the thttpd
web server was reduced by 23.5% due to the large number of files
simultaneously mmap()ed by this server. (The machine in question has
enough memory to cache most of this workload.)
Nothing comes for free: At present, I see a 0.2% slowdown on "buildworld"
due to the overhead of maintaining the splay tree. I believe that
some or all of this can be eliminated through optimizations
to the code.
Developed in collaboration with: Juan E Navarro <jnavarro@cs.rice.edu>
Reviewed by: jeff
that td_intr_nesting_level is 0 (like malloc() does). Since malloc() calls
uma we can probably remove the check in malloc() for this now. Also,
perform an extra witness check in that case to make sure we don't hold
any locks when performing a M_WAITOK allocation.
release Giant around vm_map_madvise()'s call to pmap_object_init_pt().
o Replace GIANT_REQUIRED in vm_object_madvise() with the acquisition
and release of Giant.
o Remove the acquisition and release of Giant from madvise().
several reasons before. Fixing it involved restructuring the generic hash
code to require calling code to handle locking, unlocking, and freeing hashes
on error conditions.
vm_object_deallocate(), replacing the assertion GIANT_REQUIRED.
o Remove GIANT_REQUIRED from vm_map_protect() and vm_map_simplify_entry().
o Acquire and release Giant around vm_map_protect()'s call to pmap_protect().
Altogether, these changes eliminate the need for mprotect() to acquire
and release Giant.
mallochash. Mallochash is going to go away as soon as I introduce the
kfree/kmalloc api and partially overhaul the malloc wrapper. This can't happen
until all users of the malloc api that expect memory to be aligned on the size
of the allocation are fixed.
Implement the following checks on freed memory in the bucket path:
- Slab membership
- Alignment
- Duplicate free
This previously was only done if we skipped the buckets. This code will slow
down INVARIANTS a bit, but it is smp safe. The checks were moved out of the
normal path and into hooks supplied in uma_dbg.
0xdeadc0de and then check for it just before memory is handed off as part
of a new request. This will catch any post free/pre alloc modification of
memory, as well as introduce errors for anything that tries to dereference
it as a pointer.
This code takes the form of special init, fini, ctor and dtor routines that
are specificly used by malloc. It is in a seperate file because additional
debugging aids will want to live here as well.
mutex class. Currently this is only used for kmapentzone because kmapents
are are potentially allocated when freeing memory. This is not dangerous
though because no other allocations will be done while holding the
kmapentzone lock.
i386/ia64/alpha - catch up to sparc64/ppc:
- replace pmap_kernel() with refs to kernel_pmap
- change kernel_pmap pointer to (&kernel_pmap_store)
(this is a speedup since ld can set these at compile/link time)
all platforms (as suggested by jake):
- gc unused pmap_reference
- gc unused pmap_destroy
- gc unused struct pmap.pm_count
(we never used pm_count - we track address space sharing at the vmspace)
in the same style as sys/proc.h.
o Undo the de-inlining of several trivial, MPSAFE methods on the vm_map.
(Contrary to the commit message for vm_map.h revision 1.66 and vm_map.c
revision 1.206, de-inlining these methods increased the kernel's size.)
due to conditions that suggest the possible need for stack growth.
This has two beneficial effects: (1) we can
now remove calls to vm_map_growstack() from the MD trap handlers and (2)
simple page faults are faster because we no longer unnecessarily perform
vm_map_growstack() on every page fault.
o Remove vm_map_growstack() from the i386's trap_pfault().
o Remove the acquisition and release of Giant from i386's trap_pfault().
(vm_fault() still acquires it.)
statclock can access it in the tail end of statclock_process() at an
unfortunate time. This bit me several times on an SMP alpha (UP2000)
and the problem went away with this change. I'm not sure why it doesn't
break x86 as well. Maybe it's because the clocks are much faster
on alpha (HZ=1024 by default).
and pmap_copy_page(). This gets rid of a couple more physical addresses
in upper layers, with the eventual aim of supporting PAE and dealing with
the physical addressing mostly within pmap. (We will need either 64 bit
physical addresses or page indexes, possibly both depending on the
circumstances. Leaving this to pmap itself gives more flexibilitly.)
Reviewed by: jake
Tested on: i386, ia64 and (I believe) sparc64. (my alpha was hosed)
hash while holding the lock on a zone. Fix this by doing the allocation
seperately from the actual hash expansion.
The lock is dropped before the allocation and reacquired before the expansion.
The expansion code checks to see if we lost the race and frees the new hash
if we do. We really never will lose this race because the hash expansion is
single threaded via the timeout mechanism.
Fortunately we have no large zones with maximums specified yet, so it wasn't
breaking anything.
Implement blocking when a zone exceeds the maximum and M_WAITOK is specified.
Previously this just failed like the old zone allocator did. The old zone
allocator didn't support WAITOK/NOWAIT though so we should do what we
advertise.
While I was in there I cleaned up some more zalloc logic to further simplify
that code path and reduce redundant code. This was needed to make the blocking
work properly anyway.
didn't like the wait argument and that if you were removing a zone it had
better be empty.
Also, I broke out part of hash_expand and made a seperate hash_free() for use
in uma_zdestroy.
never held across blocking operations. Also, fix two other lock order
reversals that were exposed by jhb's witness change.
The free path previously had a bug that would cause it to skip the free bucket
list in some cases and go straight to allocating a new bucket. This has been
fixed as well.
These changes made the bucket handling code much cleaner and removed quite a
few lock operations. This should be marginally faster now.
It is now possible to call malloc w/o Giant and avoid any witness warnings.
This still isn't entirely safe though because malloc_type statistics are not
protected by any lock.
relating to extreme low memory situations occured. This was only ever seen on
the port build cluster, so many thanks to kris for helping me debug this.
Tested by: kris
PCPU_LAZY_INC() which increments elements in it for cases where we
can afford the occassional inaccuracy. Use of per-cpu stats counters
avoids significant cache stalls in various critical paths that would
otherwise severely limit our cpu scaleability.
Adjust all sysctl's accessing cnt.* elements to now use a procedure
which aggregates the requested field for all cpus and for the global
vmmeter.
The global vmmeter is retained, since some stats counters, like v_free_min,
cannot be made per-cpu. Also, this allows us to convert counters from
the global vmmeter to the per-cpu vmmeter in a piecemeal fashion, so
have at it!
most cases NULL is passed, but in some cases such as network driver locks
(which use the MTX_NETWORK_LOCK macro) and UMA zone locks, a name is used.
Tested on: i386, alpha, sparc64
memory in phys_avail will fit in 'int', use vm_size_t. This fixes booting
on sparc64 machines with more than 2 gigs of ram.
Thanks to Jan Chrillesen for providing me with access to a 4 gig machine.
general cleanup of the API. The entire API now consists of two functions
similar to the pre-KSE API. The suser() function takes a thread pointer
as its only argument. The td_ucred member of this thread must be valid
so the only valid thread pointers are curthread and a few kernel threads
such as thread0. The suser_cred() function takes a pointer to a struct
ucred as its first argument and an integer flag as its second argument.
The flag is currently only used for the PRISON_ROOT flag.
Discussed on: smp@
with this flag. Remove the dup_list and dup_ok code from subr_witness. Now
we just check for the flag instead of doing string compares.
Also, switch the process lock, process group lock, and uma per cpu locks over
to this interface. The original mechanism did not work well for uma because
per cpu lock names are unique to each zone.
Approved by: jhb
where a sysctl within 20 seconds of a cache_drain could yield negative "USED"
counts.
Also, grab the uma_mtx while in the sysctl handler. This hadn't caused
problems yet because Giant is held all the time.
Reported by: kkenn
