kernel/fs: Refactor EntryCache to not use constant array sizes.

Instead set them in the Init functions. For now, the same
hard-coded sizes are used, so aside from slightly increased storage
on two classes (or not even due to padding), this has no functional change.

Add missing includes following previous commit.

All these files were making use of headers included indirectly
through AutoLock.h that are now no longer following the previous commit.

EntryCache: Add entry_cache_add_missing() for negative caching.

It provides a way for filesystems to cache a lookup failure and
therefore prevents repeated lookups of missing entries. This is a
common scenario for example in command lookup and compiling, where
each directory in PATH or each include directory is searched for the
given entry.

More useless inclusions of khash.h

kernel: atomic_*() functions rework

* No need for the atomically changed variables to be declared as
volatile.
* Drop support for atomically getting and setting unaligned data.
* Introduce atomic_get_and_set[64]() which works the same as
atomic_set[64]() used to. atomic_set[64]() does not return the
previous value anymore.

Added DebugReverseLookup() method to reverse-lookup directory and entry name
for a given vnode (for debugging purposes).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35625 a95241bf-73f2-0310-859d-f6bbb57e9c96

Entry cache:
* Moved hash computations out of the critical sections.
* Replaced the LRU entry queue by an array of entry "generations", each
containing a sparse array of entries of that generation. Whenever a
generation is full, we clear the oldest generation and continue with that
one. The main advantage of this algorithm is that entry cache's mutex could
be replaced by an r/w lock, that most of the time only has to be read
locked in Lookup(). This does dramatically decrease contention of that
lock.

The total -j8 Haiku image build speedup is marginal, but the kernel time
drops about 7% (now being smaller than the real time).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34950 a95241bf-73f2-0310-859d-f6bbb57e9c96

Moved the entry cache implementation into its own file.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34843 a95241bf-73f2-0310-859d-f6bbb57e9c96

EntryCache: Add entry_cache_add_missing() for negative caching.

It provides a way for filesystems to cache a lookup failure and
therefore prevents repeated lookups of missing entries. This is a
common scenario for example in command lookup and compiling, where
each directory in PATH or each include directory is searched for the
given entry.

More useless inclusions of khash.h

kernel: atomic_*() functions rework

* No need for the atomically changed variables to be declared as
volatile.
* Drop support for atomically getting and setting unaligned data.
* Introduce atomic_get_and_set[64]() which works the same as
atomic_set[64]() used to. atomic_set[64]() does not return the
previous value anymore.

Added DebugReverseLookup() method to reverse-lookup directory and entry name
for a given vnode (for debugging purposes).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35625 a95241bf-73f2-0310-859d-f6bbb57e9c96

Entry cache:
* Moved hash computations out of the critical sections.
* Replaced the LRU entry queue by an array of entry "generations", each
containing a sparse array of entries of that generation. Whenever a
generation is full, we clear the oldest generation and continue with that
one. The main advantage of this algorithm is that entry cache's mutex could
be replaced by an r/w lock, that most of the time only has to be read
locked in Lookup(). This does dramatically decrease contention of that
lock.

The total -j8 Haiku image build speedup is marginal, but the kernel time
drops about 7% (now being smaller than the real time).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34950 a95241bf-73f2-0310-859d-f6bbb57e9c96

Moved the entry cache implementation into its own file.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34843 a95241bf-73f2-0310-859d-f6bbb57e9c96