the wired count of manually mapped pages not to be decremented in
delete_area(), leading to a "pages still has mappings" panic when the slab
allocator's memory manager deleted areas.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35329 a95241bf-73f2-0310-859d-f6bbb57e9c96
* Added flags to avoid notifying the busy condition variable unnecessarily.
* get_writable_cached_block(): Unlock the cache while memcpy()ing/memset()ing
the block's data. The idea is to reduce lock contention. Less effective
than I hoped, though.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35328 a95241bf-73f2-0310-859d-f6bbb57e9c96
functional change (other than avoiding no-ops like subtracting 0).
* vm_page_try_reserve_pages(): Moved the kernel tracing calls from the top of
the function to the points where the reservation already succeeded.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35322 a95241bf-73f2-0310-859d-f6bbb57e9c96
argument. They replace the previous special-purpose allocation functions
(malloc_nogrow(), vip_io_request_malloc()).
* Moved the I/O VIP heap to heap.cpp accordingly.
* Added quite a bit of passing around of allocation flags in the VM,
particularly in the VM*AddressSpace classes.
* Fixed IOBuffer::GetNextVirtualVec(): It was ignoring the VIP flag and always
allocated on the normal heap.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35316 a95241bf-73f2-0310-859d-f6bbb57e9c96
on the fly, clearing and writing it each time, we now use an iovec with 32
identical entries pointing to a clear page that we prepare once at
initialization. This speeds up clear_image in low memory situations
dramatically.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35304 a95241bf-73f2-0310-859d-f6bbb57e9c96
beginning whether to pass the cache by really doesn't help when
reading/writing a huge amount of data, since a low memory situation is likely
to occur at some point during the operation. This should fix the main issue
of #3768.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35299 a95241bf-73f2-0310-859d-f6bbb57e9c96
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
Those use malloc(), which obviously doesn't work before the heap is
initialized.
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table, we only enter the slab. This also saves us the link object per object.
* Removed the now useless {Prepare,Unprepare}Object() methods.
* SmallObjectCache: Unlock the cache while calling into the MemoryManager. We
need to do that to avoid an indirect violation of the CACHE_DONT_* policy.
* Simplified lower_boundary().
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35285 a95241bf-73f2-0310-859d-f6bbb57e9c96
* 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
VMCacheRef object, since that can fail, in which case the subsequently called
Delete() would use uninitialized pointers.
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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
* 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
adding the cache to the maintenance queue. Not so important but more correct.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35255 a95241bf-73f2-0310-859d-f6bbb57e9c96
low resource handler functions. Particularly fixed the race conditions
between those and delete_object_cache().
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35254 a95241bf-73f2-0310-859d-f6bbb57e9c96
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
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
allocate a page mapping. In that case we do at least have to mark the page
not busy again. Furthermore we enforce the minimum page mappings object cache
reserve, so we'll have more luck on the next fault.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35241 a95241bf-73f2-0310-859d-f6bbb57e9c96
* 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
the CACHE_DONT_SLEEP flag to work for real, since otherwise the thread could
block on the mutex held by a thread allocating memory. We use two condition
variables to prevent multiple threads from allocating slabs at the same time.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35206 a95241bf-73f2-0310-859d-f6bbb57e9c96
* Changed the semantics of object_cache_reserve_internal(). Now it makes sure
the given number of objects are free. As a side effect this also changes
the semantics of object_cache_reserve() similarly, though I have trouble
seeing the purpose of the function in the first place.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35204 a95241bf-73f2-0310-859d-f6bbb57e9c96
one for each per CPU store):
* The depot is now protected by a R/W lock combined with a spinlock. It is
required to either hold read lock + spinlock or just the write lock.
* When accessing the per CPU stores we only need to acquire the read lock
and disable interrupts. When switching magazines with the depot we
additionally get the spinlock.
* When allocating a new magazine we do completely unlock.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35200 a95241bf-73f2-0310-859d-f6bbb57e9c96
* The threads beside the main thread are killed earlier now (in the new
team_shutdown_team()), before removing the team from the team hash and from
its process group. This fixes#5296.
* Use a condition variable instead of a semaphore to wait for the non-main
threads to die. We notify the condition right after a thread has left the
team. The semaphore was released by the undertaker.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35196 a95241bf-73f2-0310-859d-f6bbb57e9c96
function is used only in one place and the missing locking would be harmless
if it weren't for the per translation map physical page mapper. It is used to
map the page table for the lookup. Concurrent access could corrupt its data
structures, or, just as bad, the unlocked Query() could remap the page table
used by a concurrent Map() or Unmap(), which would then manipulate the
wrong page table.
Potentially messing up kernel memory, this bug could obviously cause all
kinds of kernel crashes and weird behavior. E.g. ticket #5138 is a likely
candidate, as are triple faults.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35195 a95241bf-73f2-0310-859d-f6bbb57e9c96
idea, since that would potentially add the object back to the object store
or lead to infinite recursion. When the object cache is destroyed it most
likely led to infinite loops, because the object would alternately be
removed from and added back to the object store.
* delete_object_cache(): Lock after destroying the object store, so we don't
deadlock.
* Use the object store on SMP machines. It seems to work, though I only
tested with the network stack and that seems to have problems of its own.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35182 a95241bf-73f2-0310-859d-f6bbb57e9c96
* heap_index_for(): Could return invalid index, if there hadn't been created
a set of heaps for each CPU.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35179 a95241bf-73f2-0310-859d-f6bbb57e9c96
things a bit.
* Some style cleanup.
* The object depot does now have a cookie that will be passed to the return
hook.
* Fixed object_cache_return_object_wrapper() using the new cookie.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35174 a95241bf-73f2-0310-859d-f6bbb57e9c96
When initializing driver settings, make sure to set the parameter count to 0,
because these settings have not been parsed yet. This allows us to safely free
the settings. Freeing the settings is triggered in load_driver_settings() if
we encounter settings which have been originally loaded by the boot_loader,
which might be stale. I think the bug would trigger for settings which had been
loaded by the boot_loader but had never been parsed.
With this change, I can use the userlandfs on all my machines.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35166 a95241bf-73f2-0310-859d-f6bbb57e9c96
VMCacheRef object which points to the cache. This allows to optimize
VMCache::MoveAllPages(), since it no longer needs to iterate over all pages
to adjust their cache pointer. It can simple swap the cache refs of the two
caches instead.
Reduces the total -j8 Haiku image build time only marginally. The kernel time
drops almost 10%, though.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35155 a95241bf-73f2-0310-859d-f6bbb57e9c96
* Added "bool consumerLocked" parameter to VMCache::Unlock() and
ReleaseRefAndUnlock(). Since Unlock() may cause the cache to be merged with
a consumer cache, the flag is needed to prevent a deadlock in case the
caller still holds a lock to the consumer. Hasn't been a problem yet, since
that situation never occurred.
* VMCacheChainLocker: Reversed unlocking order to bottom-up. The other
direction could cause a deadlock in case caches would be merged, since the
locking order would be reversed. The way VMCacheChainLocker was used this
didn't happen, though.
* fault_get_page(): While copying a page from a lower cache to the top cache,
we do now unlock all caches but the top one, so we don't unnecessarily
kill concurrency.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35153 a95241bf-73f2-0310-859d-f6bbb57e9c96
Also added an empty stub for _thread_do_exit_notification() when compiling for GCC2.
* Removed the check testing if the thread is already dead.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35142 a95241bf-73f2-0310-859d-f6bbb57e9c96
