Commit Graph

230 Commits

Author SHA1 Message Date
Ingo Weinhold
3caec2871a * 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
2010-01-01 20:20:11 +00:00
Ingo Weinhold
1021fd2826 * agp_gart(): Use vm_page_[un]reserve_pages().
* Removed unused vm_page_allocate_pages().
* Removed now unused (always true) "reserved" parameter from
  vm_page_allocate_page().
* Removed unused (always false) "stealActive" parameter from steal_page().


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34836 a95241bf-73f2-0310-859d-f6bbb57e9c96
2010-01-01 16:37:14 +00:00
Axel Dörfler
33c82a30c0 * While reading in a block, the block is now marked busy, and the cache
unlocked, allowing for more parallel access.
* Writing is still done synchronously, though.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34611 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-12-10 10:29:37 +00:00
Ingo Weinhold
522c2f19d4 * Added a simple mechanism to wait for events to VMCache. WaitForPageEvents()
waits for certain events on a given page, NotifyPageEvents() wakes up
  waiting threads respectively.
* Used the new feature instead of condition variables for waiting on busy
  pages. We save publishing and unpublishing of a condition variable whenever
  a page is marked busy. There's only something to do, if there's at least
  one thread waiting in the list of the respective cache. The general
  assumption is that this is only rarely the case and even if it happens,
  there should be only very few threads.
* Added an apparently missing notification in cache_io(). At least I didn't
  see the reason for it not being there.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34537 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-12-07 15:42:08 +00:00
Ingo Weinhold
be7328a9f6 Moved VMCache related definitions to <vm/VMCache.h>.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34535 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-12-07 14:14:21 +00:00
Ingo Weinhold
e50cf8765b * 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
2009-12-02 18:05:10 +00:00
Ingo Weinhold
a477e3cf20 Finished renaming of vm_cache to VMCache.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34424 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-12-01 17:45:55 +00:00
Ingo Weinhold
b0db552cd9 Renamed vm_address_space to VMAddressSpace.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34422 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-12-01 17:27:09 +00:00
Axel Dörfler
1db31d4dbd * The slab and the block cache now both also react on address space shortages.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34310 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-11-27 13:04:30 +00:00
Axel Dörfler
a10ac91f6d * NewBlock(), and Allocate() will now try to reuse existing memory in low
resource situations.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@33892 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-11-05 11:14:12 +00:00
Michael Lotz
1af7d11504 * Rework page writing to combine page writes where possible. For now the pages
are required to be physically contiguos, which should be reworked to put them
  into seperate iovecs. Still this manages to combine a great deal of page
  writes into larger bursts already. Reduces the amount of IO requests being
  scheduled (and greatly benefits media where page wise writes are slow when
  they are accessed through a non-IOScheduler path, i.e. USB mass storage until
  that is properly implemented).
* Abstracted per page page writing tasks into a PageWriteWrapper class.
* Abstracted per transfer page writing tasks into PageWriteTransfer class which
  formerly was the PageWriterCallback.
* Use both classes from the PageWriterRun and from
  vm_page_write_modified_page_range to remove code duplication.
* Adjusted synchronous VMAnonymousCache::Write() to cope correctly with larger
  iovecs and more than one iovec. It assumed that there was exactly one page per
  vector previously.
* Introduced MaxPagesPerWrite() and MaxPagesPerAsyncWrite() to VMCache to allow
  a cache to specify restricitions. VMAnonymousCache does restrict the max pages
  to 1 for WriteAsync right now as I didn't feel like reworking that one to cope
  with non single page writes just yet.
* Pulled out PageWriteTransfer methods for better readability.
* Some typo fixes.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@33507 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-10-10 22:37:26 +00:00
Artur Wyszynski
818ef0e501 Fixed wrong check
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@32326 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-08-13 17:46:39 +00:00
Axel Dörfler
cfd22919f2 * FileMap::Translate() did not choke on negative offsets, and _Cache() does not
necessarily return an error in this case.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@32129 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-08-05 13:05:58 +00:00
Axel Dörfler
61b6f38cfc * Cleanup.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@32021 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-07-31 14:11:12 +00:00
Axel Dörfler
c32499b4f7 * 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
2009-07-30 23:12:12 +00:00
Axel Dörfler
0a5bfde225 * Added stack traced to the Abort tracing output.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31870 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-07-28 21:50:42 +00:00
Axel Dörfler
61efcc328d * Cleanup.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31869 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-07-28 21:49:28 +00:00
Axel Dörfler
71d2034366 * Enhanced cache_blocks_in_main_transaction() to also return the correct number
of blocks in case there is no sub-transaction at all.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31868 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-07-28 21:47:06 +00:00
Axel Dörfler
483acc4382 * has_sub_transaction was never initialized, no clue why this didn't come up
earlier.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31845 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-07-28 14:09:28 +00:00
Axel Dörfler
eb26e782f3 * Decoupled block_cache_used_memory() from the sCachesLock - this should fix the
UI freezes (ActivityMonitor and ProcessController both use get_system_info() a
  lot), although this is only the symptom of another problem.
* The downside is that the block cache usage information isn't as up to date as
  it was previously - it's updated by the block write/notifier thread now (worst
  case every 2 seconds).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31812 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-07-27 14:59:39 +00:00
Axel Dörfler
813d9285bf * Fixed a number of problems of the "block_cache_data" command.
* Also added stack traces to each BlockData entry.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31763 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-07-26 12:18:11 +00:00
Axel Dörfler
6102f0788a * file_cache_set_size() now clears the last page of its cache if needed. This
fixes #4106 for good.
* Also removed a bit of dead code in that function.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31732 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-07-24 09:19:24 +00:00
Axel Dörfler
db8fb4fdf0 * The file cache must clear partial pages as well, since they can be mapped
directly via mmap().
* This fixes bug #4106.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31669 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-07-21 10:17:57 +00:00
Rene Gollent
008ec58d9f When building the block cache for UserlandFS's haiku emulation lib, don't include tracing since that's unavailable outside of the kernel. Fixes ticket #4092. Axel or Ingo, please review.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31525 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-07-12 03:52:52 +00:00
Axel Dörfler
9ca4077700 * Fixed a bug that let _InvalidateAfter() access already freed memory, and would
also mess up the file map, causing all sorts of file corruption.
* This fixes bug #3991 (and eventually some others).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30960 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-06-04 12:29:15 +00:00
Jérôme Duval
591bc3f2d9 * various fixes identified by gcc4, provided by Joe Prostko
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30902 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-05-28 20:36:22 +00:00
Axel Dörfler
a5dbd78b7a * Since PrecacheIO is used as asynchronous callback object, we must not access
it anymore after having called vfs_asynchronous_read_pages().
* Now, Prepare() does all the preparation work, and ReadAsync() does the actual
  work - this must be called without having the cache locked. This also fixes
  another bug where the callback would be deleted twice in case the I/O request
  failed.
* This fixes bug #3847.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30632 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-05-05 10:13:55 +00:00
Axel Dörfler
d5ad762913 Fixed several problems of the prefetching code:
* Did claim to have reserved pages when calling vm_page_allocate_page(), but
  didn't have any (copy&paste bug). We cannot use it without reserved pages,
  as we need to call vm_page_allocate_page() with a cache locked.
* No longer use low_resource_state() to determine whether to precache or not,
  but use the new vm_page_num_used_pages() instead.
* Also don't (try to) precache when the cache already has more than 2/3 of its
  pages to safe some unnecessary work.
* The size to precache was limited to the file size incorrectly.
* When precaching failed, the cache reference was not released.
* The precaching started one page too late, causing bug #3835.
* Reenabled precaching.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30515 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-04-30 15:53:41 +00:00
Stephan Aßmus
aff0fbbe57 axeld:
* vfs_read_pages_async() must not be called with locked cache,
  since it cannot be guaranteed that the operation will be
  performed asynchronously. (The ISO9660 FS for example does not
  implement the new IO hooks... yet.)


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30476 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-04-28 08:03:39 +00:00
Stephan Aßmus
eb2bd0e8e3 axeld:
* Implemented a way to do asynchronous pre-fetching when mapping files.
* There are slight code duplications in some places that could benefit
  from cleaning up, but nothing too bad.
* Implementing smarter ways to trigger prefetching and more analysis of
  the situations in the kernel would be nice. Currently up to 10 MB
  of every mapped file are pre-fetched without further analysis.
* The speed improvement is nice for certain operations. On our test
  system (real hardware), Firefox took 9 seconds from being launched
  to display a window. Now it takes 5 seconds. Both measurements
  right after booting. The same system took 35 seconds from launching
  Haiku in the GRUB menu to displaying the Tracker desktop background
  image. Now it takes 27 seconds.
* We didn't have the chance to check out the effects of this on the
  CD boot, but potentially, they could speed it up a lot.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30465 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-04-27 18:16:58 +00:00
Ingo Weinhold
65d2b8a8e9 * 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
2009-04-20 15:19:41 +00:00
Axel Dörfler
8a26f35a6d * Sequential write accesses were never detected, due to an incorrect check.
* The previous code would have scheduled a single page to be written out (if it
  would have ever been triggered), now we schedule the complete previous write
  access. This greatly speeds up a "dd if=/dev/zero of=test ..." beyond the
  size of available memory.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30276 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-04-20 08:02:51 +00:00
Axel Dörfler
d1cad26854 * Added an insane block cache tracing mode that will also log the whole block
data. This is available when BLOCK_CACHE_BLOCK_TRACING is 2 or greater.
* Completely untested as of now, though. Will do so soon.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30104 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-04-10 09:55:04 +00:00
Axel Dörfler
fd0803f300 * Added RemoveTail() method.
* Renamed DoublyLinkedList::Size() to Count(), since it actually counts the
  items (ie. O(n)).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29979 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-04-06 21:06:19 +00:00
Ingo Weinhold
98092e9867 gcc 4 fixes.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29602 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-03-18 22:43:47 +00:00
Ingo Weinhold
e055b92aac Added missing header.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29455 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-03-09 00:50:53 +00:00
Ingo Weinhold
aa4ba93e25 * 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
2009-03-08 17:30:37 +00:00
Ingo Weinhold
9bb78ee296 Removed the superfluous 'extern "C"'s.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29334 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-02-27 12:06:43 +00:00
Michael Lotz
c33667d400 Fixing warnings under GCC4 in preparation to enable -Werror there as well:
* Replaced the use of offsetof() for structs that aren't PODs. Add a
  offset_of_member() macro to util/khash.h because that's what it's used for
  in our cases.
* Change the signature of add_debugger_command()/remove_debugger_command() on
  GCC > 2 to avoid the depricated conversion from string constants to char *.
* Adding some "suggested" parenthesis. I know that not everyone likes that, but
  it pointed out at least one bug that is fixed here as well.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29113 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-02-01 20:48:02 +00:00
Axel Dörfler
55ddbd7bca * When a file system reports -1 offsets in its fs_get_file_map() function, this
will now accepted and regarded as sparse file data. FileMap::_Add() also
  correctly joins multiple vecs with that offset together, FileMap::Translate()
  will always report offset -1 even for offsets into that extent.
* read_file_io_vec_pages() (or rather, its backend common_file_io_vec_pages())
  now supports sparse files, and will just clear the memory it should read from
  offset -1 instead of passing a request to the vnode.
* ext2 now correctly reports sparse files. This should close bug #2889, as well
  as #975.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28648 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-11-14 12:06:44 +00:00
Axel Dörfler
8f1cb8fca2 * Brought the fs_shell block_cache implementation up to date, and incorporate
the fixes applied to the kernel version of it (most notably a correctly
  working block_cache_discard(), and cache_detach_sub_transaction()).
  Also switched to the new notification functions, even though it still works
  synchronously in the fs_shell.
* Minor cleanup.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28617 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-11-11 22:19:46 +00:00
Axel Dörfler
fbc2cd83dc * wait_for_notifications() must make sure that the order of the notifications
in the cache is the same as in the condition variable. It now uses the
  low-contention sCachesLock to accomplish this.
* Also added an ASSERT to make sure the notification is no longer part of the
  list at this point.
* Improved KDL command output.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28516 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-11-05 15:22:58 +00:00
Axel Dörfler
a26045b7a6 * cache_detach_sub_transaction(), and cache_abort_sub_transaction() now support
discarded blocks correctly as well.
* cache_detach_sub_transaction() left cached_block::original_data unchanged even
  if the parent data was to become current (in case the sub transaction didn't
  change the block yet). This could cause outdated blocks to be written back.
* cache_detach_sub_transaction() also set cached_block::previous_transaction
  for all blocks, not just the ones with a previous transaction. This could
  cause blocks to be written twice for no reason.
* cache_start_sub_transaction() did not change the num_blocks count for
  discarded blocks.
* block_cache_discard() now panics if the block was already changed in the
  current transaction.
* Improved test application, added more tests, revealing the above bugs in
  cache_detach_sub_transaction().
* Minor cleanup.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28514 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-11-05 13:52:34 +00:00
Axel Dörfler
ddd20af422 * Fixed a potential race condition: when wait_for_notifications() is called
from the block notifier, the cache could be deleted before we have the chance
  to lock it. We now lock the sCachesLock, and see if this cache is still valid.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28512 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-11-05 11:16:04 +00:00
Axel Dörfler
96e19c19fc * The first functions now handle the "discard" flag correctly (namely
cache_end_transaction(), and cache_start_sub_transaction()).
* Further work on the test application, it's now actually usable, first test
  passes.
* dump_block() did erroneously print 'B' for the dirty flag; now both dirty and
  discard have the 'D' (3rd and 5th column).
* block_cache::LowMemoryHandler() is now private (and got an underscore prefix).
* Minor cleanup, shuffled some methods around.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28508 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-11-04 22:40:11 +00:00
Axel Dörfler
f69f65ec96 * Cleanup, no functional change.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28497 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-11-04 15:02:09 +00:00
Axel Dörfler
5b812019b4 * Added function block_cache_discard() that flushes blocks from the block cache,
discarding their changes. This functionality currently only works correctly
  when no transactions are used.
* Started test application for the block cache, doesn't do anything yet.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28496 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-11-04 14:49:33 +00:00
Ingo Weinhold
59dbd26f5f * Moved more debug macros to kernel_debug_config.h.
* Turned the checks for all those macros to "#if"s instead of "#ifdef"s.
* Introduced macro KDEBUG_LEVEL which serves as a master setting.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28248 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-10-20 14:24:46 +00:00
Ingo Weinhold
47c40a10a1 * 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
2008-10-20 00:06:09 +00:00
Ingo Weinhold
7b8683b252 Updated write_to_cache() to use physical pages for I/O and the new
{memset,memcpy_to}_physical() functions.
Mapping lots of physical pages at once as done before was an actual
problem on systems with enough RAM, as the physical page mapper can map
only 64 chunks at a time. So multiple threads could play dining
philosophers, each getting only one of two chopsticks, waiting for
another one to be freed.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28220 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-10-17 16:45:14 +00:00