History log of /haiku/src/system/kernel/slab/MemoryManager.cpp
Revision Date Author Comments
# c650846d 14-Mar-2023 Augustin Cavalier <waddlesplash@gmail.com>

vm: Replace the VMAreas OpenHashTable with an AVLTree.

Since we used a hash table with a fixed size (1024), collisions were
obviously inevitable, meaning that while insertions would always be
fast, lookups and deletions would take linear time to search the
linked-list for the area in question. For recently-created areas,
this would be fast; for less-recently-created areas, it would get
slower and slower and slower.

A particularly pathological case was the "mmap/24-1" test from the
Open POSIX Testsuite, which creates millions of areas until it hits
ENOMEM; it then simply exits, at which point it would run for minutes
and minutes in the kernel team deletion routines; how long I don't know,
as I rebooted before it finished.

This change fixes that problem, among others, at the cost of increased
area creation time, by using an AVL tree instead of a hash. For comparison,
mmap'ing 2 million areas with the "24-1" test before this change took
around 0m2.706s of real time, while afterwards it takes about 0m3.118s,
or around a 15% increase (1.152x).

On the other hand, the total test runtime for 2 million areas went from
around 2m11.050s to 0m4.035s, or around a 97% decrease (0.031x); in other
words, with this new code, it is *32 times faster.*

Area insertion will no longer be O(1), however, so the time increase
may go up with the number of areas present on the system; but if it's
only around 3 seconds to create 2 million areas, or about 1.56 us per area,
vs. 1.35 us before, I don't think that's worth worrying about.

My nonscientific "compile HaikuDepot with 2 cores in VM" benchmark
seems to be within the realm of "noise", anyway, with most results
both before and after this change coming in around 47s real time.

Change-Id: I230e17de4f80304d082152af83db8bd5abe7b831


# 8f68daed 25-Apr-2022 Augustin Cavalier <waddlesplash@gmail.com>

kernel: Make use of the new ConditionVariable lock-switching APIs in a few places.


# e12a5fe2 08-Feb-2022 Augustin Cavalier <waddlesplash@gmail.com>

kernel/slab: Change checks in FreeRawOrReturnCache to panic instead.

The function is largely useless if we cannot lock kernel space,
and the consumers may not expect it to silently "fail." Hence,
we now put the invocation of deferred_free in free_etc directly.


# 2f001d82 09-Sep-2021 Augustin Cavalier <waddlesplash@gmail.com>

kernel/slab: Add missing support for CACHE_DONT_LOCK_KERNEL_SPACE.

This codepath is only hit for especially large malloc'd areas that
do not fit into an object cache, which is a rather rare case to
have in tandem with DONT_LOCK_KERNEL_SPACE, but we need to be
prepared for it in this code anyways.

Probably this codepath would previously have caused a hang due to
attempted double lock of the kernel addres space. Unfortunately
it appears our rw_locks do not actually detect that at present,
so likely I should investigate that next...

Change-Id: I3c9059d3e3939271beeeff221ebc921bc07ddf00
Reviewed-on: https://review.haiku-os.org/c/haiku/+/4438
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: waddlesplash <waddlesplash@gmail.com>


# 86e43bdf 09-Jul-2019 Augustin Cavalier <waddlesplash@gmail.com>

kernel: Add missing error checks to MemoryManager::_AllocateChunks.


# d1f280c8 01-Apr-2012 Hamish Morrison <hamishm53@gmail.com>

Add support for pthread_attr_get/setguardsize()

* Added the aforementioned functions.
* create_area_etc() now takes a guard size parameter.
* The thread_info::stack_base/end range now refers to the usable range
only.


# 1bd07482 11-Sep-2012 Ingo Weinhold <ingo_weinhold@gmx.de>

Fix crash in MemoryManager::PerformMaintenance()

sFreeAreaCount wasn't decremented after removing an area from
sFreeAreas, thus causing the loop to continue until enountering and
crashing on a NULL pointer after removing the last area. Introduce
helper methods _PushFreeArea() and _PopFreeArea() to ensure this cannot
easily happen again.

Fixes ticket #8972.


# c3f0fd28 12-Jul-2012 Alex Smith <alex@alex-smith.me.uk>

Fixed formatting of output in some debugger commands.

Currently all debugger commands assume 32-bit pointers when formatting their
output. This means that on x86_64 the output is incorrectly formatted. Fixed
this by adding a B_PRINTF_POINTER_WIDTH definition (16 on 64-bit, 8 on
32-bit), and using this to correctly format the output. Not all commands have
been fixed yet, but all VM, slab, VFS, team, thread and image commands should
be correct.


# 4be4fc6b 15-Jun-2012 Alex Smith <alex@alex-smith.me.uk>

More 64-bit compilation/safety fixes.


# 81fea743 02-Nov-2011 Michael Lotz <mmlr@mlotz.ch>

bonefish+mmlr:
Add MemoryManager::DebugObjectCacheForAddress() to retrieve the ObjectCache for
a certain address from KDL.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@43117 a95241bf-73f2-0310-859d-f6bbb57e9c96


# f606e8fd 01-Nov-2011 Ingo Weinhold <ingo_weinhold@gmx.de>

mmlr + bonefish:
* AllocationTrackingCallback::ProcessTrackingInfo(): Also pass the
allocation pointer.
* "allocations_per_caller" KDL command: Add option "-d". When given,
each allocation for the specified caller is printed, including the
respective stack trace.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@43087 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 50175c99 01-Nov-2011 Ingo Weinhold <ingo_weinhold@gmx.de>

mmlr + bonefish:
Refactor the "allocations_per_caller" KDL command related functions.
They expect an instance of a class implementing the new
AllocationTrackingCallback interface, now. The only implementation ATM
is AllocationCollectorCallback, which does the work the now removed
slab_debug_add_allocation_for_caller() did before.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@43082 a95241bf-73f2-0310-859d-f6bbb57e9c96


# f908ff9b 01-Nov-2011 Ingo Weinhold <ingo_weinhold@gmx.de>

mmlr + bonefish:
* Fix build broken in r43078. The slab_debug_add_allocation_for_caller()
wasn't guarded correctly.
* slab_debug_add_allocation_for_caller(): Add bool resetAllocationInfos
parameter, which makes the function clear the allocation tracking
infos after processing the data.
* "allocations_per_caller" KDL command: Add option "-r" to reset the
allocation tracking infos. The next invocation of the command will
only show the allocations made after the reset.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@43079 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 0422a0f3 01-Nov-2011 Ingo Weinhold <ingo_weinhold@gmx.de>

mmlr + bonefish:
* dump_allocations_per_caller(): Compute the total allocation count and
size from the caller infos instead of using return arguments in the
helper functions called.
* Move caller info update code from analyze_allocation_callers() to new
function slab_debug_add_allocation_for_caller(), so it can be reused.
* Add MemoryManager::AnalyzeAllocationCallers() to collect the
allocation information for the memory manager.



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@43078 a95241bf-73f2-0310-859d-f6bbb57e9c96


# e1c6140e 01-Nov-2011 Ingo Weinhold <ingo_weinhold@gmx.de>

mmlr + bonefish:
* Add optional stack trace capturing for slab memory manager tracing.
* Add allocation tracking for the slab allocator (enabled via
SLAB_ALLOCATION_TRACKING). The allocation tracking requires tracing
with stack traces to be enabled for object caches and/or the memory
manager.
- Add class AllocationTrackingInfo that associates an allocation with
its respective tracing entry. The structure is added to the end of
an allocation done by the memory manager. For the object caches
there's a separate array for each slab.
- Add code range markers to the slab code, so that the first caller
into the slab code can be retrieved from the stack traces.
- Add KDL command "allocations_per_caller" that lists all allocations
summarized by caller.
* Move debug definitions from slab_private.h to slab_debug.h.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@43072 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 72156a40 31-Oct-2011 Michael Lotz <mmlr@mlotz.ch>

bonefish+mmlr:
* Introduce "paranoid" malloc/free into the slab allocator (initializing
allocated memory to 0xcc and setting freed memory to 0xdeadbeef).
* Allow for optional stack traces for slab object cache tracing.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@43046 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 1e393751 06-Jul-2011 Ingo Weinhold <ingo_weinhold@gmx.de>

MemoryManager::_GetChunks(): Fixed incorrect check. The area structure offset
introduced in r37701 was not taken into account for computing the short meta
chunk size. Fixes the reopened #6237.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@42385 a95241bf-73f2-0310-859d-f6bbb57e9c96


# e653b865 22-Jul-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

Free(), FreeRawOrReturnCache(), GetAllocationInfo(), CacheForAddress(): Check
Assert that the meta chunk the given address lies in is actually in use.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37703 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 93a56baf 22-Jul-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

Moved the Area structure from the beginning of area to one page inside the
area. The first page is not mapped, so someone writing over the bounds of the
previous area will be axed immediately.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37701 a95241bf-73f2-0310-859d-f6bbb57e9c96


# b9447668 10-Jul-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

* Moved the vm_page initialization from vm_page.cpp:vm_page_init() to the new
vm_page::Init().
* Made vm_page::wired_count private and added accessor methods.
* Added VMCache::fWiredPagesCount (the number of wired pages the cache
contains) and accessor methods.
* Made more use of vm_page::IsMapped().
* vm_copy_on_write_area(): Added vm_page_reservation* parameter that can be
used to request a special handling for wired pages. If given the wired pages
are replaced by copies and the original pages are moved to the upper cache.
* vm_copy_area():
- We don't need to do any wired ranges handling, if the source area is a
B_SHARED_AREA, since we don't touch the area's mappings in this case.
- We no longer wait for wired ranges of the concerned areas to disappear.
Instead we use the new vm_copy_on_write_area() feature and just let it
copy the wired pages. This fixes #6288, an issue introduced with the use
of user mutexes in libroot: When executing multiple concurrent fork()s all
but the first one would wait on the fork mutex, which (being a user mutex)
would wire a page that the vm_copy_area() of the first fork() would wait
for.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37460 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 05951b9b 02-Jul-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

* Added optional paranoid checking of the slab memory manager meta chunks
after each chunk allocation/deallocation.
* The commands that dump chunks also verify, whether chunks that look free
are in the free list.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37360 a95241bf-73f2-0310-859d-f6bbb57e9c96


# a8ad734f 14-Jun-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

* Introduced structures {virtual,physical}_address_restrictions, which specify
restrictions for virtual/physical addresses.
* vm_page_allocate_page_run():
- Fixed conversion of base/limit to array indexes. sPhysicalPageOffset was not
taken into account.
- Takes a physical_address_restrictions instead of base/limit and also
supports alignment and boundary restrictions, now.
* map_backing_store(), VM[User,Kernel]AddressSpace::InsertArea()/
ReserveAddressRange() take a virtual_address_restrictions parameter, now. They
also support an alignment independent from the range size.
* create_area_etc(), vm_create_anonymous_area(): Take
{virtual,physical}_address_restrictions parameters, now.
* Removed no longer needed B_PHYSICAL_BASE_ADDRESS.
* DMAResources:
- Fixed potential overflows of uint32 when initializing from device node
attributes.
- Fixed bounce buffer creation TODOs: By using create_area_etc() with the
new restrictions parameters we can directly support physical high address,
boundary, and alignment.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37131 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 2ea7b17c 09-Jun-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

* vm_allocate_early(): Replace "bool blockAlign" parameter by a more flexible
"addr_t aligmnent".
* X86PagingMethod32Bit::PhysicalPageSlotPool::InitInitial(),
generic_vm_physical_page_mapper_init(): Use vm_allocate_early()'s alignment
feature instead of aligning by hand.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37070 a95241bf-73f2-0310-859d-f6bbb57e9c96


# c1be1e07 01-May-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

* VMTranslationMap::Map()/Protect(): Added "memoryType" parameter. Not
implemented for any architecture yet.
* vm_set_area_memory_type(): Call VMTranslationMap::ProtectArea() to change the
memory type for the already mapped pages.



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@36574 a95241bf-73f2-0310-859d-f6bbb57e9c96


# a93fa3c9 02-Mar-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

More debug output.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35725 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 40bb9481 03-Feb-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

* Removed useless return parameter from vm_remove_all_page_mappings().
* Added vm_clear_page_mapping_accessed_flags() and
vm_remove_all_page_mappings_if_unaccessed(), which combine the functionality
of vm_test_map_activation(), vm_clear_map_flags(), and
vm_remove_all_page_mappings(), thus saving lots of calls to translation map
methods. The backend is the new method
VMTranslationMap::ClearAccessedAndModified().
* Started to make use of the cached page queue and changed the meaning of the
other non-free queues slightly:
- Active queue: Contains mapped pages that have been used recently.
- Inactive queue: Contains mapped pages that have not been used recently. Also
contains unmapped temporary pages.
- Modified queue: Contains unmapped modified pages.
- Cached queue: Contains unmapped unmodified pages (LRU sorted).
Unless we're actually low on memory and actively do paging, modified and
cached queues only contain non-temporary pages. Cached pages are considered
quasi free. They still belong to a cache, but since they are unmodified and
unmapped, they can be freed immediately. And this is what
vm_page_[try_]reserve_pages() do now when there are no more actually free
pages at hand. Essentially this means that pages storing cached file data,
unless mmap()ped, no longer are considered used and don't contribute to page
pressure. Paging will not happen as long there are enough free + cached pages
available.
* Reimplemented the page daemon. It no longer scans all pages, but instead works
the page queues. As long as the free pages situation is harmless, it only
iterates through the active queue and deactivates pages that have not been
used recently. When paging occurs it additionally scans the inactive queue and
frees pages that have not been used recently.
* Changed the page reservation/allocation interface:
vm_page_[try_]reserve_pages(), vm_page_unreserve_pages(), and
vm_page_allocate_page() now take a vm_page_reservation structure pointer.
The reservation functions initialize the structure -- currently consisting
only of a count member for the number of still reserved pages.
vm_page_allocate_page() decrements the count and vm_page_unreserve_pages()
unreserves the remaining pages (if any). Advantages are that reservation/
unreservation mismatches cannot occur anymore, that vm_page_allocate_page()
can verify that the caller has indeed a reserved page left, and that there's
no unnecessary pressure on the free page pool anymore. The only disadvantage
is that the vm_page_reservation object needs to be passed around a bit.
* Reworked the page reservation implementation:
- Got rid of sSystemReservedPages and sPageDeficit. Instead
sUnreservedFreePages now actually contains the number of free pages that
have not yet been reserved (it cannot become negative anymore) and the new
sUnsatisfiedPageReservations contains the number of pages that are still
needed for reservation.
- Threads waiting for reservations do now add themselves to a waiter queue,
which is ordered by descending priority (VM priority and thread priority).
High priority waiters are served first when pages become available.
Fixes #5328.
* cache_prefetch_vnode(): Would reserve one less page than allocated later, if
the size wasn't page aligned.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35393 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 0e81d474 30-Jan-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

Don't access the area after deleting it.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35340 a95241bf-73f2-0310-859d-f6bbb57e9c96


# e65c4002 29-Jan-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

* Replaced the vm_page_allocate_page*() "pageState" parameter by a more
general "flags" parameter. It encodes the target state of the page -- so
that the page isn't unnecessarily put in the wrong page queue first -- a
flag whether the page should be cleared, and one to indicate whether the
page should be marked busy.
* Added page state PAGE_STATE_CACHED. Not used yet.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35333 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 72382fa6 29-Jan-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

* Removed the page state PAGE_STATE_BUSY and instead introduced a vm_page::busy
flag. The obvious advantage is that one can still see what state a page is in
and even move it between states while being marked busy.
* Removed the vm_page::is_dummy flag. Instead we mark marker pages busy, which
in all cases has the same effect. Introduced a vm_page_is_dummy() that can
still check whether a given page is a dummy page.
* vm_page_unreserve_pages(): Before adding to the system reserve make sure
sUnreservedFreePages is non-negative. Otherwise we'd make nonexisting pages
available for allocation. steal_pages() still has the same problem and it
can't be solved that easily.
* map_page(): No longer changes the page state/mark the page unbusy. That's the
caller's responsibility.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35331 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 1196f305 29-Jan-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

Unconditionally log when the memory manager creates/deletes areas.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35330 a95241bf-73f2-0310-859d-f6bbb57e9c96


# cff6e9e4 26-Jan-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

* The system now holds back a small reserve of committable memory and pages. The
memory and page reservation functions have a new "priority" parameter that
indicates how deep the function may tap into that reserve. The currently
existing priority levels are "user", "system", and "VIP". The idea is that
user programs should never be able to cause a state that gets the kernel into
trouble due to heavy battling for memory. The "VIP" level (not really used
yet) is intended for allocations that are required to free memory eventually
(in the page writer). More levels are thinkable in the future, like "user real
time" or "user system server".
* Added "priority" parameters to several VMCache methods.
* Replaced the map_backing_store() "unmapAddressRange" parameter by a "flags"
parameter.
* Added area creation flag CREATE_AREA_PRIORITY_VIP and slab allocator flag
CACHE_PRIORITY_VIP indicating the importance of the request.
* Changed most code to pass the right priorities/flags.

These changes already significantly improve the behavior in low memory
situations. I've tested a bit with 64 MB (virtual) RAM and, while not
particularly fast and responsive, the system remains at least usable under high
memory pressure.
As a side effect the slab allocator can now be used as general memory allocator.
Not done by default yet, though.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35295 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 30f2c6c8 25-Jan-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

When we create areas for large raw allocations there's no need to allocate
clear pages.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35286 a95241bf-73f2-0310-859d-f6bbb57e9c96


# b4e5e498 25-Jan-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

MemoryManager:
* Added support to do larger raw allocations (up to one large chunk (128 pages))
in the slab areas. For an even larger allocation an area is created (haven't
seen that happen yet, though).
* Added kernel tracing (SLAB_MEMORY_MANAGER_TRACING).
* _FreeArea(): Copy and paste bug: The meta chunks of the to be freed area
would be added to the free lists instead of being removed from them. This
would corrupt the lists and also lead to all kinds of misuse of meta chunks.

object caches:
* Implemented CACHE_ALIGN_ON_SIZE. It is no longer set for all small object
caches, but the block allocator sets it on all power of two size caches.
* object_cache_reserve_internal(): Detect recursion and don't wait in such a
case. The function could deadlock itself, since
HashedObjectCache::CreateSlab() does allocate memory, thus potentially
reentering.
* object_cache_low_memory():
- I missed some returns when reworking that one in r35254, so the function
might stop early and also leave the cache in maintenance mode, which would
cause it to be ignored by object cache resizer and low memory handler from
that point on.
- Since ReturnSlab() potentially unlocks, the conditions weren't quite correct
and too many slabs could be freed.
- Simplified things a bit.
* object_cache_alloc(): Since object_cache_reserve_internal() does potentially
unlock the cache, the situation might have changed and their might not be an
empty slab available, but a partial one. The function would crash.
* Renamed the object cache tracing variable to SLAB_OBJECT_CACHE_TRACING.
* Renamed debugger command "cache_info" to "slab_cache" to avoid confusion with
the VMCache commands.
* ObjectCache::usage was not maintained anymore since I introduced the
MemoryManager. object_cache_get_usage() would thus always return 0 and the
block cache would not be considered cached memory. This was only of
informational relevance, though.

slab allocator misc.:
* Disable the object depots of block allocator caches for object sizes > 2 KB.
Allocations of those sizes aren't so common that the object depots yield any
benefit.
* The slab allocator is now fully self-sufficient. It allocates its bootstrap
memory from the MemoryManager, and the hash tables for HashedObjectCaches use
the block allocator instead of the heap, now.
* Added option to use the slab allocator for malloc() and friends
(USE_SLAB_ALLOCATOR_FOR_MALLOC). Currently disabled. Works in principle and
has virtually no lock contention. Handling for low memory situations is yet
missing, though.
* Improved the output of some debugger commands.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35283 a95241bf-73f2-0310-859d-f6bbb57e9c96


# c3f84a1d 23-Jan-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

_FreeChunk(): When freeing a chunk from a formerly full meta chunk, we have
to add it back to its partial list or it would be leaked.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35266 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 5726fbda 23-Jan-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

MemoryManager:
* Does now keep one or two empty areas around, so that even in case of
CACHE_DONT_LOCK_KERNEL_SPACE memory can be provided as long as pages are
available. The object cache maintainer thread is used to asynchronously
allocate/delete the free areas.
* Added new debugger commands "slab_meta_chunk[s]" and improved the existing
ones.
* Moved Area::chunks to MetaChunk.
* Removed unused _AllocationArea() "chunkSize" parameter.
* Fixed serious bug in _FreeChunk(): Empty meta chunks were not removed from
the partial chunk lists and could thus be used twice.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35264 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 10189b50 23-Jan-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

Changed the memory management algorithm: Instead of designating the area for
a certain chunk size, the areas are split into meta chunks (which are as
large as a large chunk) each of which can be a used independently for chunks
of a certain size. This reduces the vulnerablity to fragmentation, so that we
need fewer areas overall.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35250 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 8d1316fd 22-Jan-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

Replaced CACHE_DONT_SLEEP by two new flags CACHE_DONT_WAIT_FOR_MEMORY and
CACHE_DONT_LOCK_KERNEL_SPACE. If the former is given, the slab memory manager
does not wait when reserving memory or pages. The latter prevents area
operations. The new flags add a bit of flexibility. E.g. when allocating page
mapping objects for userland areas CACHE_DONT_WAIT_FOR_MEMORY is sufficient,
i.e. the allocation will succeed as long as pages are available.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35246 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 86c794e5 21-Jan-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

slab allocator:
* Implemented a more elaborated raw memory allocation backend (MemoryManager).
We allocate 8 MB areas whose pages we allocate and map when needed. An area is
divided into equally-sized chunks which form the basic units of allocation. We
have areas with three possible chunk sizes (small, medium, large), which is
basically what the ObjectCache implementations were using anyway.
* Added "uint32 flags" parameter to several of the slab allocator's object
cache and object depot functions. E.g. object_depot_store() potentially wants
to allocate memory for a magazine. But also in pure freeing functions it
might eventually become useful to have those flags, since they could end up
deleting an area, which might not be allowable in all situations. We should
introduce specific flags to indicate that.
* Reworked the block allocator. Since the MemoryManager allocates block-aligned
areas, maintains a hash table for lookup, and maps chunks to object caches,
we can quickly find out which object cache a to be freed allocation belongs
to and thus don't need the boundary tags anymore.
* Reworked the slab boot strap process. We allocate from the initial area only
when really necessary, i.e. when the object cache for the respective
allocation size has not been created yet. A single page is thus sufficient.

other:
* vm_allocate_early(): Added boolean "blockAlign" parameter. If true, the
semantics is the same as for B_ANY_KERNEL_BLOCK_ADDRESS.
* Use an object cache for page mappings. This significantly reduces the
contention on the heap bin locks.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35232 a95241bf-73f2-0310-859d-f6bbb57e9c96


# d1f280c80529d5f0bc55030c2934f9255bc7f6a2 01-Apr-2012 Hamish Morrison <hamishm53@gmail.com>

Add support for pthread_attr_get/setguardsize()

* Added the aforementioned functions.
* create_area_etc() now takes a guard size parameter.
* The thread_info::stack_base/end range now refers to the usable range
only.


# 1bd07482531e9fae514212e729ce94eb7b534f42 11-Sep-2012 Ingo Weinhold <ingo_weinhold@gmx.de>

Fix crash in MemoryManager::PerformMaintenance()

sFreeAreaCount wasn't decremented after removing an area from
sFreeAreas, thus causing the loop to continue until enountering and
crashing on a NULL pointer after removing the last area. Introduce
helper methods _PushFreeArea() and _PopFreeArea() to ensure this cannot
easily happen again.

Fixes ticket #8972.


# c3f0fd28cda13d70a8c092003609442e4e29cf78 12-Jul-2012 Alex Smith <alex@alex-smith.me.uk>

Fixed formatting of output in some debugger commands.

Currently all debugger commands assume 32-bit pointers when formatting their
output. This means that on x86_64 the output is incorrectly formatted. Fixed
this by adding a B_PRINTF_POINTER_WIDTH definition (16 on 64-bit, 8 on
32-bit), and using this to correctly format the output. Not all commands have
been fixed yet, but all VM, slab, VFS, team, thread and image commands should
be correct.


# 4be4fc6b1faddbd037146214a0011d320842b4f3 15-Jun-2012 Alex Smith <alex@alex-smith.me.uk>

More 64-bit compilation/safety fixes.


# 81fea743949e8fcd9f7738204f5853b2cd15c868 02-Nov-2011 Michael Lotz <mmlr@mlotz.ch>

bonefish+mmlr:
Add MemoryManager::DebugObjectCacheForAddress() to retrieve the ObjectCache for
a certain address from KDL.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@43117 a95241bf-73f2-0310-859d-f6bbb57e9c96


# f606e8fd79b26ccfa5a7a50e3caeb560ab1ac9a9 01-Nov-2011 Ingo Weinhold <ingo_weinhold@gmx.de>

mmlr + bonefish:
* AllocationTrackingCallback::ProcessTrackingInfo(): Also pass the
allocation pointer.
* "allocations_per_caller" KDL command: Add option "-d". When given,
each allocation for the specified caller is printed, including the
respective stack trace.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@43087 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 50175c99c4747dcc83dcdeff24c259500cbf7478 01-Nov-2011 Ingo Weinhold <ingo_weinhold@gmx.de>

mmlr + bonefish:
Refactor the "allocations_per_caller" KDL command related functions.
They expect an instance of a class implementing the new
AllocationTrackingCallback interface, now. The only implementation ATM
is AllocationCollectorCallback, which does the work the now removed
slab_debug_add_allocation_for_caller() did before.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@43082 a95241bf-73f2-0310-859d-f6bbb57e9c96


# f908ff9bb658aa86aa53760c51070415e69f951d 01-Nov-2011 Ingo Weinhold <ingo_weinhold@gmx.de>

mmlr + bonefish:
* Fix build broken in r43078. The slab_debug_add_allocation_for_caller()
wasn't guarded correctly.
* slab_debug_add_allocation_for_caller(): Add bool resetAllocationInfos
parameter, which makes the function clear the allocation tracking
infos after processing the data.
* "allocations_per_caller" KDL command: Add option "-r" to reset the
allocation tracking infos. The next invocation of the command will
only show the allocations made after the reset.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@43079 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 0422a0f3ae8f12f32bd27868a7e742293786f0a0 01-Nov-2011 Ingo Weinhold <ingo_weinhold@gmx.de>

mmlr + bonefish:
* dump_allocations_per_caller(): Compute the total allocation count and
size from the caller infos instead of using return arguments in the
helper functions called.
* Move caller info update code from analyze_allocation_callers() to new
function slab_debug_add_allocation_for_caller(), so it can be reused.
* Add MemoryManager::AnalyzeAllocationCallers() to collect the
allocation information for the memory manager.



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@43078 a95241bf-73f2-0310-859d-f6bbb57e9c96


# e1c6140eaa641aa95fc6d82f0d5c53cf4fe41a16 01-Nov-2011 Ingo Weinhold <ingo_weinhold@gmx.de>

mmlr + bonefish:
* Add optional stack trace capturing for slab memory manager tracing.
* Add allocation tracking for the slab allocator (enabled via
SLAB_ALLOCATION_TRACKING). The allocation tracking requires tracing
with stack traces to be enabled for object caches and/or the memory
manager.
- Add class AllocationTrackingInfo that associates an allocation with
its respective tracing entry. The structure is added to the end of
an allocation done by the memory manager. For the object caches
there's a separate array for each slab.
- Add code range markers to the slab code, so that the first caller
into the slab code can be retrieved from the stack traces.
- Add KDL command "allocations_per_caller" that lists all allocations
summarized by caller.
* Move debug definitions from slab_private.h to slab_debug.h.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@43072 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 72156a402f54ea4be9dc3e3e9704c612f7d9ad16 31-Oct-2011 Michael Lotz <mmlr@mlotz.ch>

bonefish+mmlr:
* Introduce "paranoid" malloc/free into the slab allocator (initializing
allocated memory to 0xcc and setting freed memory to 0xdeadbeef).
* Allow for optional stack traces for slab object cache tracing.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@43046 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 1e393751ba7363de3c6b76be6ffd277b5f6fdb54 06-Jul-2011 Ingo Weinhold <ingo_weinhold@gmx.de>

MemoryManager::_GetChunks(): Fixed incorrect check. The area structure offset
introduced in r37701 was not taken into account for computing the short meta
chunk size. Fixes the reopened #6237.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@42385 a95241bf-73f2-0310-859d-f6bbb57e9c96


# e653b86511ca373abd4cf624978f59aa5d7790b9 22-Jul-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

Free(), FreeRawOrReturnCache(), GetAllocationInfo(), CacheForAddress(): Check
Assert that the meta chunk the given address lies in is actually in use.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37703 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 93a56baf09e19689d669f7f24f8cf74b23c7b4b3 22-Jul-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

Moved the Area structure from the beginning of area to one page inside the
area. The first page is not mapped, so someone writing over the bounds of the
previous area will be axed immediately.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37701 a95241bf-73f2-0310-859d-f6bbb57e9c96


# b9447668707741085389f650383b018d33d7d0bf 10-Jul-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

* Moved the vm_page initialization from vm_page.cpp:vm_page_init() to the new
vm_page::Init().
* Made vm_page::wired_count private and added accessor methods.
* Added VMCache::fWiredPagesCount (the number of wired pages the cache
contains) and accessor methods.
* Made more use of vm_page::IsMapped().
* vm_copy_on_write_area(): Added vm_page_reservation* parameter that can be
used to request a special handling for wired pages. If given the wired pages
are replaced by copies and the original pages are moved to the upper cache.
* vm_copy_area():
- We don't need to do any wired ranges handling, if the source area is a
B_SHARED_AREA, since we don't touch the area's mappings in this case.
- We no longer wait for wired ranges of the concerned areas to disappear.
Instead we use the new vm_copy_on_write_area() feature and just let it
copy the wired pages. This fixes #6288, an issue introduced with the use
of user mutexes in libroot: When executing multiple concurrent fork()s all
but the first one would wait on the fork mutex, which (being a user mutex)
would wire a page that the vm_copy_area() of the first fork() would wait
for.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37460 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 05951b9b6a3bbf94106b2167283166aae78af820 02-Jul-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

* Added optional paranoid checking of the slab memory manager meta chunks
after each chunk allocation/deallocation.
* The commands that dump chunks also verify, whether chunks that look free
are in the free list.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37360 a95241bf-73f2-0310-859d-f6bbb57e9c96


# a8ad734f1c698917badb15e1641e0f38b3e9a013 14-Jun-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

* Introduced structures {virtual,physical}_address_restrictions, which specify
restrictions for virtual/physical addresses.
* vm_page_allocate_page_run():
- Fixed conversion of base/limit to array indexes. sPhysicalPageOffset was not
taken into account.
- Takes a physical_address_restrictions instead of base/limit and also
supports alignment and boundary restrictions, now.
* map_backing_store(), VM[User,Kernel]AddressSpace::InsertArea()/
ReserveAddressRange() take a virtual_address_restrictions parameter, now. They
also support an alignment independent from the range size.
* create_area_etc(), vm_create_anonymous_area(): Take
{virtual,physical}_address_restrictions parameters, now.
* Removed no longer needed B_PHYSICAL_BASE_ADDRESS.
* DMAResources:
- Fixed potential overflows of uint32 when initializing from device node
attributes.
- Fixed bounce buffer creation TODOs: By using create_area_etc() with the
new restrictions parameters we can directly support physical high address,
boundary, and alignment.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37131 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 2ea7b17cf341036024bd84c4f791f332b2e15e48 09-Jun-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

* vm_allocate_early(): Replace "bool blockAlign" parameter by a more flexible
"addr_t aligmnent".
* X86PagingMethod32Bit::PhysicalPageSlotPool::InitInitial(),
generic_vm_physical_page_mapper_init(): Use vm_allocate_early()'s alignment
feature instead of aligning by hand.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37070 a95241bf-73f2-0310-859d-f6bbb57e9c96


# c1be1e0761d0904d99dabd3d1638d94802b4b600 01-May-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

* VMTranslationMap::Map()/Protect(): Added "memoryType" parameter. Not
implemented for any architecture yet.
* vm_set_area_memory_type(): Call VMTranslationMap::ProtectArea() to change the
memory type for the already mapped pages.



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@36574 a95241bf-73f2-0310-859d-f6bbb57e9c96


# a93fa3c9ea06751239205e2f4630ce2b2a0aec30 02-Mar-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

More debug output.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35725 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 40bb94819e6c39d72ab29edc1a0dcd80b15b8b42 03-Feb-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

* Removed useless return parameter from vm_remove_all_page_mappings().
* Added vm_clear_page_mapping_accessed_flags() and
vm_remove_all_page_mappings_if_unaccessed(), which combine the functionality
of vm_test_map_activation(), vm_clear_map_flags(), and
vm_remove_all_page_mappings(), thus saving lots of calls to translation map
methods. The backend is the new method
VMTranslationMap::ClearAccessedAndModified().
* Started to make use of the cached page queue and changed the meaning of the
other non-free queues slightly:
- Active queue: Contains mapped pages that have been used recently.
- Inactive queue: Contains mapped pages that have not been used recently. Also
contains unmapped temporary pages.
- Modified queue: Contains unmapped modified pages.
- Cached queue: Contains unmapped unmodified pages (LRU sorted).
Unless we're actually low on memory and actively do paging, modified and
cached queues only contain non-temporary pages. Cached pages are considered
quasi free. They still belong to a cache, but since they are unmodified and
unmapped, they can be freed immediately. And this is what
vm_page_[try_]reserve_pages() do now when there are no more actually free
pages at hand. Essentially this means that pages storing cached file data,
unless mmap()ped, no longer are considered used and don't contribute to page
pressure. Paging will not happen as long there are enough free + cached pages
available.
* Reimplemented the page daemon. It no longer scans all pages, but instead works
the page queues. As long as the free pages situation is harmless, it only
iterates through the active queue and deactivates pages that have not been
used recently. When paging occurs it additionally scans the inactive queue and
frees pages that have not been used recently.
* Changed the page reservation/allocation interface:
vm_page_[try_]reserve_pages(), vm_page_unreserve_pages(), and
vm_page_allocate_page() now take a vm_page_reservation structure pointer.
The reservation functions initialize the structure -- currently consisting
only of a count member for the number of still reserved pages.
vm_page_allocate_page() decrements the count and vm_page_unreserve_pages()
unreserves the remaining pages (if any). Advantages are that reservation/
unreservation mismatches cannot occur anymore, that vm_page_allocate_page()
can verify that the caller has indeed a reserved page left, and that there's
no unnecessary pressure on the free page pool anymore. The only disadvantage
is that the vm_page_reservation object needs to be passed around a bit.
* Reworked the page reservation implementation:
- Got rid of sSystemReservedPages and sPageDeficit. Instead
sUnreservedFreePages now actually contains the number of free pages that
have not yet been reserved (it cannot become negative anymore) and the new
sUnsatisfiedPageReservations contains the number of pages that are still
needed for reservation.
- Threads waiting for reservations do now add themselves to a waiter queue,
which is ordered by descending priority (VM priority and thread priority).
High priority waiters are served first when pages become available.
Fixes #5328.
* cache_prefetch_vnode(): Would reserve one less page than allocated later, if
the size wasn't page aligned.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35393 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 0e81d474e796f6ece7a8dc637aa394f48e2988fc 30-Jan-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

Don't access the area after deleting it.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35340 a95241bf-73f2-0310-859d-f6bbb57e9c96


# e65c400299386f99a251395ff2e59572705d7e49 29-Jan-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

* Replaced the vm_page_allocate_page*() "pageState" parameter by a more
general "flags" parameter. It encodes the target state of the page -- so
that the page isn't unnecessarily put in the wrong page queue first -- a
flag whether the page should be cleared, and one to indicate whether the
page should be marked busy.
* Added page state PAGE_STATE_CACHED. Not used yet.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35333 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 72382fa6291e810be2949a70abd8f274f92dbd2c 29-Jan-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

* Removed the page state PAGE_STATE_BUSY and instead introduced a vm_page::busy
flag. The obvious advantage is that one can still see what state a page is in
and even move it between states while being marked busy.
* Removed the vm_page::is_dummy flag. Instead we mark marker pages busy, which
in all cases has the same effect. Introduced a vm_page_is_dummy() that can
still check whether a given page is a dummy page.
* vm_page_unreserve_pages(): Before adding to the system reserve make sure
sUnreservedFreePages is non-negative. Otherwise we'd make nonexisting pages
available for allocation. steal_pages() still has the same problem and it
can't be solved that easily.
* map_page(): No longer changes the page state/mark the page unbusy. That's the
caller's responsibility.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35331 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 1196f305d77621e74d4ad4f439d543f6885355d6 29-Jan-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

Unconditionally log when the memory manager creates/deletes areas.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35330 a95241bf-73f2-0310-859d-f6bbb57e9c96


# cff6e9e406132a76bfc20cb35ff5228dd0ba94d8 26-Jan-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

* The system now holds back a small reserve of committable memory and pages. The
memory and page reservation functions have a new "priority" parameter that
indicates how deep the function may tap into that reserve. The currently
existing priority levels are "user", "system", and "VIP". The idea is that
user programs should never be able to cause a state that gets the kernel into
trouble due to heavy battling for memory. The "VIP" level (not really used
yet) is intended for allocations that are required to free memory eventually
(in the page writer). More levels are thinkable in the future, like "user real
time" or "user system server".
* Added "priority" parameters to several VMCache methods.
* Replaced the map_backing_store() "unmapAddressRange" parameter by a "flags"
parameter.
* Added area creation flag CREATE_AREA_PRIORITY_VIP and slab allocator flag
CACHE_PRIORITY_VIP indicating the importance of the request.
* Changed most code to pass the right priorities/flags.

These changes already significantly improve the behavior in low memory
situations. I've tested a bit with 64 MB (virtual) RAM and, while not
particularly fast and responsive, the system remains at least usable under high
memory pressure.
As a side effect the slab allocator can now be used as general memory allocator.
Not done by default yet, though.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35295 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 30f2c6c8599407d744e7979d7fe69db725ec343e 25-Jan-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

When we create areas for large raw allocations there's no need to allocate
clear pages.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35286 a95241bf-73f2-0310-859d-f6bbb57e9c96


# b4e5e4982360e684c5a13d227b9a958dbe725554 25-Jan-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

MemoryManager:
* Added support to do larger raw allocations (up to one large chunk (128 pages))
in the slab areas. For an even larger allocation an area is created (haven't
seen that happen yet, though).
* Added kernel tracing (SLAB_MEMORY_MANAGER_TRACING).
* _FreeArea(): Copy and paste bug: The meta chunks of the to be freed area
would be added to the free lists instead of being removed from them. This
would corrupt the lists and also lead to all kinds of misuse of meta chunks.

object caches:
* Implemented CACHE_ALIGN_ON_SIZE. It is no longer set for all small object
caches, but the block allocator sets it on all power of two size caches.
* object_cache_reserve_internal(): Detect recursion and don't wait in such a
case. The function could deadlock itself, since
HashedObjectCache::CreateSlab() does allocate memory, thus potentially
reentering.
* object_cache_low_memory():
- I missed some returns when reworking that one in r35254, so the function
might stop early and also leave the cache in maintenance mode, which would
cause it to be ignored by object cache resizer and low memory handler from
that point on.
- Since ReturnSlab() potentially unlocks, the conditions weren't quite correct
and too many slabs could be freed.
- Simplified things a bit.
* object_cache_alloc(): Since object_cache_reserve_internal() does potentially
unlock the cache, the situation might have changed and their might not be an
empty slab available, but a partial one. The function would crash.
* Renamed the object cache tracing variable to SLAB_OBJECT_CACHE_TRACING.
* Renamed debugger command "cache_info" to "slab_cache" to avoid confusion with
the VMCache commands.
* ObjectCache::usage was not maintained anymore since I introduced the
MemoryManager. object_cache_get_usage() would thus always return 0 and the
block cache would not be considered cached memory. This was only of
informational relevance, though.

slab allocator misc.:
* Disable the object depots of block allocator caches for object sizes > 2 KB.
Allocations of those sizes aren't so common that the object depots yield any
benefit.
* The slab allocator is now fully self-sufficient. It allocates its bootstrap
memory from the MemoryManager, and the hash tables for HashedObjectCaches use
the block allocator instead of the heap, now.
* Added option to use the slab allocator for malloc() and friends
(USE_SLAB_ALLOCATOR_FOR_MALLOC). Currently disabled. Works in principle and
has virtually no lock contention. Handling for low memory situations is yet
missing, though.
* Improved the output of some debugger commands.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35283 a95241bf-73f2-0310-859d-f6bbb57e9c96


# c3f84a1df542f9accc1ed208c940f2b59cdd0680 23-Jan-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

_FreeChunk(): When freeing a chunk from a formerly full meta chunk, we have
to add it back to its partial list or it would be leaked.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35266 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 5726fbda3ccb0b57c3504053a67110dd0d3922bd 23-Jan-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

MemoryManager:
* Does now keep one or two empty areas around, so that even in case of
CACHE_DONT_LOCK_KERNEL_SPACE memory can be provided as long as pages are
available. The object cache maintainer thread is used to asynchronously
allocate/delete the free areas.
* Added new debugger commands "slab_meta_chunk[s]" and improved the existing
ones.
* Moved Area::chunks to MetaChunk.
* Removed unused _AllocationArea() "chunkSize" parameter.
* Fixed serious bug in _FreeChunk(): Empty meta chunks were not removed from
the partial chunk lists and could thus be used twice.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35264 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 10189b502d840f2adc5e8d98fdc4fc4d54eb15ca 23-Jan-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

Changed the memory management algorithm: Instead of designating the area for
a certain chunk size, the areas are split into meta chunks (which are as
large as a large chunk) each of which can be a used independently for chunks
of a certain size. This reduces the vulnerablity to fragmentation, so that we
need fewer areas overall.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35250 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 8d1316fd23616f6dac131a0eba5dab08acc6e76d 22-Jan-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

Replaced CACHE_DONT_SLEEP by two new flags CACHE_DONT_WAIT_FOR_MEMORY and
CACHE_DONT_LOCK_KERNEL_SPACE. If the former is given, the slab memory manager
does not wait when reserving memory or pages. The latter prevents area
operations. The new flags add a bit of flexibility. E.g. when allocating page
mapping objects for userland areas CACHE_DONT_WAIT_FOR_MEMORY is sufficient,
i.e. the allocation will succeed as long as pages are available.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35246 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 86c794e5c10f1b2d99d672d424a8637639c703dd 21-Jan-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

slab allocator:
* Implemented a more elaborated raw memory allocation backend (MemoryManager).
We allocate 8 MB areas whose pages we allocate and map when needed. An area is
divided into equally-sized chunks which form the basic units of allocation. We
have areas with three possible chunk sizes (small, medium, large), which is
basically what the ObjectCache implementations were using anyway.
* Added "uint32 flags" parameter to several of the slab allocator's object
cache and object depot functions. E.g. object_depot_store() potentially wants
to allocate memory for a magazine. But also in pure freeing functions it
might eventually become useful to have those flags, since they could end up
deleting an area, which might not be allowable in all situations. We should
introduce specific flags to indicate that.
* Reworked the block allocator. Since the MemoryManager allocates block-aligned
areas, maintains a hash table for lookup, and maps chunks to object caches,
we can quickly find out which object cache a to be freed allocation belongs
to and thus don't need the boundary tags anymore.
* Reworked the slab boot strap process. We allocate from the initial area only
when really necessary, i.e. when the object cache for the respective
allocation size has not been created yet. A single page is thus sufficient.

other:
* vm_allocate_early(): Added boolean "blockAlign" parameter. If true, the
semantics is the same as for B_ANY_KERNEL_BLOCK_ADDRESS.
* Use an object cache for page mappings. This significantly reduces the
contention on the heap bin locks.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35232 a95241bf-73f2-0310-859d-f6bbb57e9c96