mmlr (distracted) + bonefish:
* Turn VMCache::consumers C list into a DoublyLinkedList.
* Use object caches for the different VMCache types and the VMCacheRefs.
The purpose is to reduce slab area fragmentation.
* Requires the introduction of a pure virtual VMCache::DeleteObject()
method, implemented in the derived classes.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@43133 a95241bf-73f2-0310-859d-f6bbb57e9c96

Style cleanup. No functional change.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@43122 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Renamed cache_type_to_string() to vm_cache_type_to_string() and made in
kernel private.
* Moved dumping code from dump_cache() to new VMCache::Dump().
* Override VMCache::Dump() in VMVnodeCache to also print the vnode.
* Removed no longer needed VMCache::GetLock().


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37138 a95241bf-73f2-0310-859d-f6bbb57e9c96

Fixed more address types related issues. Mostly printf() or comparison
warnings, but also some oversights from earlier changes.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37000 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Introduced type generic_io_vec, which is similar to iovec, but uses types
that are wide enough for both virtual and physical addresses.
* DMABuffer, IORequest, IOScheduler,... and code using them: Use
generic_io_vec and generic_{addr,size}_t where necessary.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@36997 a95241bf-73f2-0310-859d-f6bbb57e9c96

* VMCache::Resize(): Corrected TODO comment.
* Changed the semantics of VMCache::HasPage(). It was interpreted
inconsistently by the derived classes. Now it returns whether the backing
store can provide the page (via Read()). The default implementation returns
false. VNodeCache::HasPage() only returns true, if the given offset is
within the cache (i.e. file) bounds. This prevents vm_soft_fault() from
adding clean pages to vnode caches on faults beyond the file bounds.
Probably fixes #5473 -- at least mmap_resize_test behaves correctly, now.
* Removed redundant HasPage() and Fault() overrides in VMCache derived
classes.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@36374 a95241bf-73f2-0310-859d-f6bbb57e9c96

VMVnodeCache::AcquireUnreferencedStoreRef(): We put the wrong vnode when ours
was already deleted.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35483 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Introduced {malloc,memalign,free}_etc() which take an additional "flags"
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

* Resolved TODO in free_vnode(): There was a race condition between vnode
destruction and VMVnodeCache::AcquireUnreferencedStoreRef(). Solved by
adding a flag to VMVnodeCache and letting AcquireUnreferencedStoreRef()
fail, if set.
* Added TODO regarding replacing the snooze() waiting for busy vnodes.
* get_vnode(): Unlock sVnodeMutex while calling the put_vnode() hook on
error.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34841 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Moved the VM headers into subdirectory vm/.
* Renamed vm_cache.h/vm_address_space.h to VMCache.h/VMAddressSpace.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34449 a95241bf-73f2-0310-859d-f6bbb57e9c96

Renamed vm_address_space to VMAddressSpace.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34422 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Since the file_map reports its chunk with a file system specific alignment, we
cannot assume that the file is that long - we need to check for the actual
file size specifically, and then clear the extraneous bytes based on that one.
* This fixes seeing old file left-overs in the space beyond the file size in
mmapped file. Thanks to Oliver who provided me with a nice test program to
reproduce this problem (this should also fix gcc's fix_includes app (although
I wonder what it does if a file actually ends on a page boundary).
* Also fixed a bug in precaching that would cause the last page of the cache
to be discarded, causing it to be re-read later on.
* Moved partial page clearing into its own function
read_pages_and_clear_partial(), even though it's currently only used once.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@32001 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Introduces VMCache::CanWritePage() returning whether the given cache can
theoretically write the given page.
* page writer: Fixed the incorrect check whether a temporary page can be
written by using the new CanWritePage().


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30281 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Renamed src/system/kernel/device_manager/io_requests.{h,cpp} to
IORequest.{h,cpp}.
* Introduced public <io_requests.h> header. Currently it only declares the
single function BFS uses.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29446 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Prefixed memset_physical() and memcpy_to_physical() with "vm_",
added vm_memcpy_from_physical() and vm_memcpy_physical_page(), and
added respective functions to the vm_translation_map operations. The
architecture specific implementation can now decide how to implement
them most efficiently. Added generic implementations that can be used,
though.
* Changed vm_{get,put}_physical_page(). The former no longer accepts
flags (the only flag PHYSICAL_PAGE_DONT_WAIT wasn't needed anymore).
Instead it returns an implementation-specific handle that has to be
passed to the latter. Added vm_{get,put}_physical_page_current_cpu()
and *_debug() variants, that work only for the current CPU,
respectively when in the kernel debugger. Also adjusted the
vm_translation_map operations accordingly.
* Made consequent use of the physical memory operations in the source
tree.
* Also adjusted the m68k and ppc implementations with respect to the
vm_translation_map operation changes, but they are probably broken,
nevertheless.
* For x86 the generic physical page mapper isn't used anymore. It is
suboptimal in any case. For systems with small memory it is too much
overhead, since one can just map the complete physical memory (that's
not done yet, though). For systems with large memory it counteracts
the VM strategy to reuse the least recently used pages. Since those
pages will most likely not be mapped by the page mapper anymore, it
will keep remapping chunks. This was also the reason why building
Haiku in Haiku was significantly faster with only 256 MB RAM (since
that much could be kept mapped all the time).
Now we're using a different strategy: We have small pools of virtual
page slots per CPU that are used for the physical page operations
(memset_physical(), memcpy_*_physical()) with CPU-pinned thread.
Furthermore we have four slots per translation map, which are used to
map page tables.

These changes speed up the Haiku image build in Haiku significantly. On
my Core2 Duo 2.2 GHz 2 GB machine about 40% to 20 min 40 s (KDEBUG
disabled, block cache debug disabled). Still more than factor 3 slower
than FreeBSD and Linux, though.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28244 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Moved memset_physical() to vm.cpp and made it available in the kernel.
* Added memcpy_to_physical().


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28219 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Added "flags" parameter to VMCache::Read().
* Use the new VMCache::Read() flags parameter to directly read into the
physical page in the page fault handler instead of mapping it first.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27966 a95241bf-73f2-0310-859d-f6bbb57e9c96

* VMCache::Write(): Added "uint32 flags" argument which is supposed to
be passed on to the IORequest. Most relevantly physical pages can now
be written directly by passing B_PHYSICAL_IO_REQUEST.
* Added VMCache::WriteAsync() which is supposed to write pages
asynchronously. The base class version version falls back to the
synchronous Write(). Only VMVnodeCache implements WriteAsync() ATM,
VMAnonymousCache (swap support) still has to be adjusted accordingly.
* write_page() doesn't need to map the page anymore as it can write the
physical page directly.
* Modified the page writer to write pages asynchronously. This shouldn't
have any noticeable effect yet. It will though as soon as the I/O
scheduler reorders I/O operations.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27056 a95241bf-73f2-0310-859d-f6bbb57e9c96

* It is now supported that I/O operations and requests are only handled
partially (e.g. due to hitting the end of file). The respective
classes have grown new methods and attributes to deal with that. The
"finished" callbacks have got additional parameters to indicate
whether the transfer was only partial and how much has been
transferred. Other callbacks and functions have a size_t* in/out
parameter instead of a simple size_t, now.
* vfs_{read,write}_pages() do now use the I/O request framework instead
of the underlying FS's {read,write}_pages() hooks (those should be
unused now). Furthermore they've got an additional "flags" parameter,
which is passed to IORequest::Init(), i.e. it allows to specify that
the given vecs refer to physical addresses.
* The file cache's read_into_cache() reads directly into physical
pages, now.
* Fixed bug in DoIO::IO(): The offset was not adjusted, so that all
pages were incorrectly transferred from/to the same location.
* Fixed broken subrequest scheduling loop head in
do_iterative_fd_io_iterate().
* Adjusted the test driver and implemented its io() hook. Using this
driver I/O requests are passed all the way from the VFS/VM to the
driver and through the I/O scheduler. It even seems to work. :-)
* Added missing const to the iovec* parameter of the IORequest::Init()
methods.
* Disabled some debug output by default. Added new optional debug
output.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26692 a95241bf-73f2-0310-859d-f6bbb57e9c96

* bfs_fsync() was the only place which could cause the
fs_vnode_ops::write_pages() to be called with fsReenter = true. Since
this is no longer the case, the argument has become superfluous. For
read_pages() it always was. Removed the argument from the functions
and all functions that propagated it.
* Some whitespace at the end of lines was removed.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26579 a95241bf-73f2-0310-859d-f6bbb57e9c96

Merged branch haiku/branches/developer/bonefish/vm into trunk. This
introduces the following relevant changes:
* VMCache:
- Renamed vm_cache to VMCache, merged it with vm_store and made it a
C++ class with virtual methods (replacing the store operations).
Turned the different store implementations into subclasses.
- Introduced MergeStore() callback, changed semantics of Commit().
- Changed locking and referencing semantics. A reference can only be
acquired/released with the cache locked. An unreferenced cache is
deleted and a mergeable cache merged when it is unlocked. This
removes the "busy" state of a cache and simplifies the page fault
code.
* Added VMAnonymousCache, which will implement swap support (work by
Zhao Shuai). It is not integrated and used yet, though.
* Enabled the mutex/recursive lock holder asserts.
* Fixed DoublyLinkedList::Swap().
* Generalized the low memory handler to a low resource handler. And made
semaphores and reserved memory handled resources. Made
vm_try_resource_memory() optionally wait (with timeout), and used that
feature to reserve memory for areas.
...


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26572 a95241bf-73f2-0310-859d-f6bbb57e9c96

store_acquire_unreferenced_ref() saves the pointer of the vnode it got
from the call to vfs_get_vnode() now. Only this way it is safe to call
store_release_ref() later (as the page writer does). We had a potential
race condition -- if called after vm_cache_remove_consumer() had
released the last reference, the old vnode might already have been
deleted.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24386 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Extracted file_map API out of the file cache - it's now an optional service
that can be used by file systems.
* Changed the way the file cache works: instead of reading/writing to the
underlying device directly, it can now be used for any data source, ie.
also network file systems.
* As a result, the former pages_io() moved to the VFS layer, and can now be
called by a file system via {read|write}_file_io_vec_pages() (naming
suggestions are always welcomed :-)). It now gets an FD, and uses that to
communicate with the device (via its fs_{read|write}_pages() hooks).
* The file_cache_{read|write}() functions must now be called without holding
an I/O relevant file system lock. That allows the file cache to prepare the
pages without colliding with the page writer, IOW the "mayBlock" flag can
go into the attic again (yay!).
* This also results in a much better performance when the system does I/O and
is low on memory, as the page writer can now finally write back some pages,
and that even without maxing out the CPU :)
* The API changes put slightly more burden on the fs_{read|write}_pages()
hooks, but in combination with the file_map it's still pretty straight
forward. It just will have to dispatch the call to the underlying device
directly, usually it will just call its fs_{read|write}_pages() hooks
via the above mentioned calls.
* Ported BFS and FAT to the new API, the latter has not been tested, though.
* Also ported the API changes to the fs_shell. I also completely removed its
file cache level page handling - the downside is that device access is no
longer cached (ie. depends on the host OS now), the upside is that the code
is greatly simplified.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@22886 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Added a "canWait" argument to vfs_get_vnode() - you can use this to ignore
busy vnodes.
* dir_create_entry_ref() used get_vnode() incorrectly (and could therefore
potentially prevent a file system from doing proper locking when called
from the kernel).
* The vnode_store now uses this for its acquire_unreferenced_ref()
implementation (and therefore for the page writer).
* read_into_cache() and write_to_cache() were still marked inline.
* The system will now wait 10 secs for a busy vnode before returning an error.
* It will also no longer panic in that case.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@22485 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Added a acquire_unreferenced_ref() to vm_store
* his has to be used by the page writer to make sure the vnode is still valid.
* This should have been the final nail on the Luposian bug - I haven't tested
it yet, but we'll certainly see :-)


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@22462 a95241bf-73f2-0310-859d-f6bbb57e9c96

* fs_{write|read}_pages() now has an additional argument "mayBlock".
* the page writer don't allow to block, while all other writers do. This fixes
bug #1509. The reason the page writer needs this is because it marks several
pages from different caches as busy.
* Fixed a warning about ASSERT being defined already in BFS, since
util/DoublyLinkedList.h now includes debug.h.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@22434 a95241bf-73f2-0310-859d-f6bbb57e9c96

bonefish+axeld:
* Removed the vm_cache/vm_store ref_count duality that besides being a bit ugly
also created the page dameon cache retrieval problem: now, only areas (and
cache consumers) retrieve a reference to the store (and therefore, the vnode).
The page daemon doesn't need to care about this at all anymore, and the pseudo
references of the vm_cache could be removed again.
* Rearranged deletion of vnodes such that its ID can be reused directly after
fs_remove_vnode() has been called.
* vm_page_allocate_page() no longer panics when it runs out of pages, but just
waits for new pages to become available using the new sFreeCondition condition
variable - to make sure this happens in an acceptable time frame, it'll
trigger a run of the low memory handlers.
* Implemented a page_thief() that steals inactive pages from caches and puts
them into the free queue. It runs as a low memory handler.
* The file cache now sets the usage count on the pages it inserts into the
cache (needs some rework though, cache_io() doesn't do it yet).
* Instead of panicking, the kernel will currently dead lock in low memory
situations, since BFS does a bit too much in bfs_release_vnode().
* Some minor cleanup.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@22315 a95241bf-73f2-0310-859d-f6bbb57e9c96

Added a "reenter" parameter to the {read|write}_pages() functions to give file
systems a chance to know if they have locked already.
This fixes a locking problem in BFS where one thread tried to acquire two read
locks (where someone else trying to acquire a write lock would have caused a
dead lock).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@17108 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Fixed the strange vm_cache_ref reference count mechanism: now, a fresh
vm_cache_ref starts with a reference count of 1. When acquiring a vm_cache,
you no longer need to worry if that should go through the vm_store, or not;
as it now always does.
* map_backing_store() no longer needs to play with the vm_cache_ref
references.
* that simplified some code.
* vfs_get_vnode_cache() now grabs a reference to the cache, if successful.
* better balanced vnode ownership on vnode_store creation (vnode_store
released the vnode before if its creation failed).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@15641 a95241bf-73f2-0310-859d-f6bbb57e9c96

Renamed vfs_vnode_acquire_ref() to vnode_acquire_vnode().
Removed vfs_vnode_release_ref(), as vfs_put_vnode() already does the same thing.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@13867 a95241bf-73f2-0310-859d-f6bbb57e9c96

Renamed system/core to system/kernel.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@12360 a95241bf-73f2-0310-859d-f6bbb57e9c96

mmlr (distracted) + bonefish:
* Turn VMCache::consumers C list into a DoublyLinkedList.
* Use object caches for the different VMCache types and the VMCacheRefs.
The purpose is to reduce slab area fragmentation.
* Requires the introduction of a pure virtual VMCache::DeleteObject()
method, implemented in the derived classes.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@43133 a95241bf-73f2-0310-859d-f6bbb57e9c96

Style cleanup. No functional change.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@43122 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Renamed cache_type_to_string() to vm_cache_type_to_string() and made in
kernel private.
* Moved dumping code from dump_cache() to new VMCache::Dump().
* Override VMCache::Dump() in VMVnodeCache to also print the vnode.
* Removed no longer needed VMCache::GetLock().


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37138 a95241bf-73f2-0310-859d-f6bbb57e9c96

Fixed more address types related issues. Mostly printf() or comparison
warnings, but also some oversights from earlier changes.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37000 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Introduced type generic_io_vec, which is similar to iovec, but uses types
that are wide enough for both virtual and physical addresses.
* DMABuffer, IORequest, IOScheduler,... and code using them: Use
generic_io_vec and generic_{addr,size}_t where necessary.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@36997 a95241bf-73f2-0310-859d-f6bbb57e9c96

* VMCache::Resize(): Corrected TODO comment.
* Changed the semantics of VMCache::HasPage(). It was interpreted
inconsistently by the derived classes. Now it returns whether the backing
store can provide the page (via Read()). The default implementation returns
false. VNodeCache::HasPage() only returns true, if the given offset is
within the cache (i.e. file) bounds. This prevents vm_soft_fault() from
adding clean pages to vnode caches on faults beyond the file bounds.
Probably fixes #5473 -- at least mmap_resize_test behaves correctly, now.
* Removed redundant HasPage() and Fault() overrides in VMCache derived
classes.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@36374 a95241bf-73f2-0310-859d-f6bbb57e9c96

VMVnodeCache::AcquireUnreferencedStoreRef(): We put the wrong vnode when ours
was already deleted.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35483 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Introduced {malloc,memalign,free}_etc() which take an additional "flags"
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

* Resolved TODO in free_vnode(): There was a race condition between vnode
destruction and VMVnodeCache::AcquireUnreferencedStoreRef(). Solved by
adding a flag to VMVnodeCache and letting AcquireUnreferencedStoreRef()
fail, if set.
* Added TODO regarding replacing the snooze() waiting for busy vnodes.
* get_vnode(): Unlock sVnodeMutex while calling the put_vnode() hook on
error.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34841 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Moved the VM headers into subdirectory vm/.
* Renamed vm_cache.h/vm_address_space.h to VMCache.h/VMAddressSpace.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34449 a95241bf-73f2-0310-859d-f6bbb57e9c96

Renamed vm_address_space to VMAddressSpace.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34422 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Since the file_map reports its chunk with a file system specific alignment, we
cannot assume that the file is that long - we need to check for the actual
file size specifically, and then clear the extraneous bytes based on that one.
* This fixes seeing old file left-overs in the space beyond the file size in
mmapped file. Thanks to Oliver who provided me with a nice test program to
reproduce this problem (this should also fix gcc's fix_includes app (although
I wonder what it does if a file actually ends on a page boundary).
* Also fixed a bug in precaching that would cause the last page of the cache
to be discarded, causing it to be re-read later on.
* Moved partial page clearing into its own function
read_pages_and_clear_partial(), even though it's currently only used once.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@32001 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Introduces VMCache::CanWritePage() returning whether the given cache can
theoretically write the given page.
* page writer: Fixed the incorrect check whether a temporary page can be
written by using the new CanWritePage().


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30281 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Renamed src/system/kernel/device_manager/io_requests.{h,cpp} to
IORequest.{h,cpp}.
* Introduced public <io_requests.h> header. Currently it only declares the
single function BFS uses.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29446 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Prefixed memset_physical() and memcpy_to_physical() with "vm_",
added vm_memcpy_from_physical() and vm_memcpy_physical_page(), and
added respective functions to the vm_translation_map operations. The
architecture specific implementation can now decide how to implement
them most efficiently. Added generic implementations that can be used,
though.
* Changed vm_{get,put}_physical_page(). The former no longer accepts
flags (the only flag PHYSICAL_PAGE_DONT_WAIT wasn't needed anymore).
Instead it returns an implementation-specific handle that has to be
passed to the latter. Added vm_{get,put}_physical_page_current_cpu()
and *_debug() variants, that work only for the current CPU,
respectively when in the kernel debugger. Also adjusted the
vm_translation_map operations accordingly.
* Made consequent use of the physical memory operations in the source
tree.
* Also adjusted the m68k and ppc implementations with respect to the
vm_translation_map operation changes, but they are probably broken,
nevertheless.
* For x86 the generic physical page mapper isn't used anymore. It is
suboptimal in any case. For systems with small memory it is too much
overhead, since one can just map the complete physical memory (that's
not done yet, though). For systems with large memory it counteracts
the VM strategy to reuse the least recently used pages. Since those
pages will most likely not be mapped by the page mapper anymore, it
will keep remapping chunks. This was also the reason why building
Haiku in Haiku was significantly faster with only 256 MB RAM (since
that much could be kept mapped all the time).
Now we're using a different strategy: We have small pools of virtual
page slots per CPU that are used for the physical page operations
(memset_physical(), memcpy_*_physical()) with CPU-pinned thread.
Furthermore we have four slots per translation map, which are used to
map page tables.

These changes speed up the Haiku image build in Haiku significantly. On
my Core2 Duo 2.2 GHz 2 GB machine about 40% to 20 min 40 s (KDEBUG
disabled, block cache debug disabled). Still more than factor 3 slower
than FreeBSD and Linux, though.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28244 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Moved memset_physical() to vm.cpp and made it available in the kernel.
* Added memcpy_to_physical().


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28219 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Added "flags" parameter to VMCache::Read().
* Use the new VMCache::Read() flags parameter to directly read into the
physical page in the page fault handler instead of mapping it first.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27966 a95241bf-73f2-0310-859d-f6bbb57e9c96

* VMCache::Write(): Added "uint32 flags" argument which is supposed to
be passed on to the IORequest. Most relevantly physical pages can now
be written directly by passing B_PHYSICAL_IO_REQUEST.
* Added VMCache::WriteAsync() which is supposed to write pages
asynchronously. The base class version version falls back to the
synchronous Write(). Only VMVnodeCache implements WriteAsync() ATM,
VMAnonymousCache (swap support) still has to be adjusted accordingly.
* write_page() doesn't need to map the page anymore as it can write the
physical page directly.
* Modified the page writer to write pages asynchronously. This shouldn't
have any noticeable effect yet. It will though as soon as the I/O
scheduler reorders I/O operations.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27056 a95241bf-73f2-0310-859d-f6bbb57e9c96

* It is now supported that I/O operations and requests are only handled
partially (e.g. due to hitting the end of file). The respective
classes have grown new methods and attributes to deal with that. The
"finished" callbacks have got additional parameters to indicate
whether the transfer was only partial and how much has been
transferred. Other callbacks and functions have a size_t* in/out
parameter instead of a simple size_t, now.
* vfs_{read,write}_pages() do now use the I/O request framework instead
of the underlying FS's {read,write}_pages() hooks (those should be
unused now). Furthermore they've got an additional "flags" parameter,
which is passed to IORequest::Init(), i.e. it allows to specify that
the given vecs refer to physical addresses.
* The file cache's read_into_cache() reads directly into physical
pages, now.
* Fixed bug in DoIO::IO(): The offset was not adjusted, so that all
pages were incorrectly transferred from/to the same location.
* Fixed broken subrequest scheduling loop head in
do_iterative_fd_io_iterate().
* Adjusted the test driver and implemented its io() hook. Using this
driver I/O requests are passed all the way from the VFS/VM to the
driver and through the I/O scheduler. It even seems to work. :-)
* Added missing const to the iovec* parameter of the IORequest::Init()
methods.
* Disabled some debug output by default. Added new optional debug
output.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26692 a95241bf-73f2-0310-859d-f6bbb57e9c96

* bfs_fsync() was the only place which could cause the
fs_vnode_ops::write_pages() to be called with fsReenter = true. Since
this is no longer the case, the argument has become superfluous. For
read_pages() it always was. Removed the argument from the functions
and all functions that propagated it.
* Some whitespace at the end of lines was removed.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26579 a95241bf-73f2-0310-859d-f6bbb57e9c96

Merged branch haiku/branches/developer/bonefish/vm into trunk. This
introduces the following relevant changes:
* VMCache:
- Renamed vm_cache to VMCache, merged it with vm_store and made it a
C++ class with virtual methods (replacing the store operations).
Turned the different store implementations into subclasses.
- Introduced MergeStore() callback, changed semantics of Commit().
- Changed locking and referencing semantics. A reference can only be
acquired/released with the cache locked. An unreferenced cache is
deleted and a mergeable cache merged when it is unlocked. This
removes the "busy" state of a cache and simplifies the page fault
code.
* Added VMAnonymousCache, which will implement swap support (work by
Zhao Shuai). It is not integrated and used yet, though.
* Enabled the mutex/recursive lock holder asserts.
* Fixed DoublyLinkedList::Swap().
* Generalized the low memory handler to a low resource handler. And made
semaphores and reserved memory handled resources. Made
vm_try_resource_memory() optionally wait (with timeout), and used that
feature to reserve memory for areas.
...


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26572 a95241bf-73f2-0310-859d-f6bbb57e9c96

store_acquire_unreferenced_ref() saves the pointer of the vnode it got
from the call to vfs_get_vnode() now. Only this way it is safe to call
store_release_ref() later (as the page writer does). We had a potential
race condition -- if called after vm_cache_remove_consumer() had
released the last reference, the old vnode might already have been
deleted.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24386 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Extracted file_map API out of the file cache - it's now an optional service
that can be used by file systems.
* Changed the way the file cache works: instead of reading/writing to the
underlying device directly, it can now be used for any data source, ie.
also network file systems.
* As a result, the former pages_io() moved to the VFS layer, and can now be
called by a file system via {read|write}_file_io_vec_pages() (naming
suggestions are always welcomed :-)). It now gets an FD, and uses that to
communicate with the device (via its fs_{read|write}_pages() hooks).
* The file_cache_{read|write}() functions must now be called without holding
an I/O relevant file system lock. That allows the file cache to prepare the
pages without colliding with the page writer, IOW the "mayBlock" flag can
go into the attic again (yay!).
* This also results in a much better performance when the system does I/O and
is low on memory, as the page writer can now finally write back some pages,
and that even without maxing out the CPU :)
* The API changes put slightly more burden on the fs_{read|write}_pages()
hooks, but in combination with the file_map it's still pretty straight
forward. It just will have to dispatch the call to the underlying device
directly, usually it will just call its fs_{read|write}_pages() hooks
via the above mentioned calls.
* Ported BFS and FAT to the new API, the latter has not been tested, though.
* Also ported the API changes to the fs_shell. I also completely removed its
file cache level page handling - the downside is that device access is no
longer cached (ie. depends on the host OS now), the upside is that the code
is greatly simplified.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@22886 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Added a "canWait" argument to vfs_get_vnode() - you can use this to ignore
busy vnodes.
* dir_create_entry_ref() used get_vnode() incorrectly (and could therefore
potentially prevent a file system from doing proper locking when called
from the kernel).
* The vnode_store now uses this for its acquire_unreferenced_ref()
implementation (and therefore for the page writer).
* read_into_cache() and write_to_cache() were still marked inline.
* The system will now wait 10 secs for a busy vnode before returning an error.
* It will also no longer panic in that case.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@22485 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Added a acquire_unreferenced_ref() to vm_store
* his has to be used by the page writer to make sure the vnode is still valid.
* This should have been the final nail on the Luposian bug - I haven't tested
it yet, but we'll certainly see :-)


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@22462 a95241bf-73f2-0310-859d-f6bbb57e9c96

* fs_{write|read}_pages() now has an additional argument "mayBlock".
* the page writer don't allow to block, while all other writers do. This fixes
bug #1509. The reason the page writer needs this is because it marks several
pages from different caches as busy.
* Fixed a warning about ASSERT being defined already in BFS, since
util/DoublyLinkedList.h now includes debug.h.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@22434 a95241bf-73f2-0310-859d-f6bbb57e9c96

bonefish+axeld:
* Removed the vm_cache/vm_store ref_count duality that besides being a bit ugly
also created the page dameon cache retrieval problem: now, only areas (and
cache consumers) retrieve a reference to the store (and therefore, the vnode).
The page daemon doesn't need to care about this at all anymore, and the pseudo
references of the vm_cache could be removed again.
* Rearranged deletion of vnodes such that its ID can be reused directly after
fs_remove_vnode() has been called.
* vm_page_allocate_page() no longer panics when it runs out of pages, but just
waits for new pages to become available using the new sFreeCondition condition
variable - to make sure this happens in an acceptable time frame, it'll
trigger a run of the low memory handlers.
* Implemented a page_thief() that steals inactive pages from caches and puts
them into the free queue. It runs as a low memory handler.
* The file cache now sets the usage count on the pages it inserts into the
cache (needs some rework though, cache_io() doesn't do it yet).
* Instead of panicking, the kernel will currently dead lock in low memory
situations, since BFS does a bit too much in bfs_release_vnode().
* Some minor cleanup.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@22315 a95241bf-73f2-0310-859d-f6bbb57e9c96

Added a "reenter" parameter to the {read|write}_pages() functions to give file
systems a chance to know if they have locked already.
This fixes a locking problem in BFS where one thread tried to acquire two read
locks (where someone else trying to acquire a write lock would have caused a
dead lock).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@17108 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Fixed the strange vm_cache_ref reference count mechanism: now, a fresh
vm_cache_ref starts with a reference count of 1. When acquiring a vm_cache,
you no longer need to worry if that should go through the vm_store, or not;
as it now always does.
* map_backing_store() no longer needs to play with the vm_cache_ref
references.
* that simplified some code.
* vfs_get_vnode_cache() now grabs a reference to the cache, if successful.
* better balanced vnode ownership on vnode_store creation (vnode_store
released the vnode before if its creation failed).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@15641 a95241bf-73f2-0310-859d-f6bbb57e9c96

Renamed vfs_vnode_acquire_ref() to vnode_acquire_vnode().
Removed vfs_vnode_release_ref(), as vfs_put_vnode() already does the same thing.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@13867 a95241bf-73f2-0310-859d-f6bbb57e9c96

Renamed system/core to system/kernel.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@12360 a95241bf-73f2-0310-859d-f6bbb57e9c96