Commit Graph
5 Commits
Author SHA1 Message Date
Ingo Weinhold c3f84a1df5 _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
2010-01-23 16:06:19 +00:00
Ingo Weinhold 5726fbda3c 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
2010-01-23 14:46:04 +00:00
Ingo Weinhold 10189b502d 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
2010-01-23 09:14:01 +00:00
Ingo Weinhold 8d1316fd23 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
2010-01-22 21:19:23 +00:00
Ingo Weinhold 86c794e5c1 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
2010-01-21 23:10:52 +00:00