Implements merging of file-backed VMA's.  Based on Andrea's 2.4 patch.

It's only done for mmap().  mprotect() and mremap() still will not merge
VMA's.

It works for hugetlbfs mappings also.

pagecache can be reclaimed via the page LRU and via prune_icache.  We
currently don't know how much reclaim is happening via each.

The patch adds instrumentation to display the number of pages which were
freed via prune_icache.  This is displayed in /proc/vmstat:pginodesteal and
/proc/vmstat:kswapd_inodesteal.

Turns out that under some workloads (well, dbench at least), fully half of
page reclaim is via the unused inode list.  Which seems quite OK to me.

A static function in a header where presumably a static inline was intended.

An implementation of posix_fadvise64().  It adds 368 bytes to my vmlinux and
is worth it.

I didn't bother doing posix_fadvise(), as userspace can implement that by
calling fadvise64().

The main reason for wanting this syscall is to provide userspace with the
ability to explicitly shoot down pagecache when streaming large files.  This
is what O_STEAMING does, only posix_fadvise() is standards-based, and harder
to use.

posix_fadvise() also subsumes sys_readahead().

POSIX_FADV_WILLNEED will generally provide asynchronous readahead semantics
for small amounts of I/O.  As long as things like indirect blocks are aready
in core.

POSIX_FADV_RANDOM gives unprivileged applications a way of disabling
readahead on a per-fd basis, which may provide some benefit for super-seeky
access patterns such as databases.



The POSIX_FADV_* values are already implemented in glibc, and this patch
ensures that they are in sync.

A test app (fadvise.c) is available in ext3 CVS.  See

	http://www.zip.com.au/~akpm/linux/ext3/

for CVS details.

Ulrich has reviewed this patch (thanks).

into penguin.transmeta.com:/home/penguin/torvalds/repositories/kernel/linux

One of the goals of the whole new modversions implementation:
export-objs is gone for good!

into shaggy.austin.ibm.com:/shaggy/bk/jfs-2.5

o Build modules with CONFIG_MODVERSIONS when just saying "make"
o Ignore generated *.ver.c files
o Fix a typo (Sam Ravnborg)
o Fix another typo (Paul Marinceu)

into tp1.ruhr-uni-bochum.de:/scratch/kai/kernel/v2.5/linux-2.5.make

Skip over the first part of __vermagic in modversioning is on: otherwise
you'll have to force it when changing from 2.6.0 to 2.6.1.

Fix the case where no CRCs are supplied (OK, but taints kernel), and
only print one tainted message (otherwise --force gives hundreds of them).

We generated the intermediate files that contain checksums for
unresolved symbols in .tmp_versions, which had the disadvantage
that is obscured what's going on during the build. Just
generate them as .ver.[co] right next to the actual objects in the
object tree.

CONFIG_MODVERSIONING was a temporary name introduced to distinguish
between the old and new module version implementation. Since the
traces of the old implementation are now gone from the build system,
we rename the config option back in order to not confuse users more
than necessary in 2.6.
 
Also, remove some historic modversions cruft throughout the tree.

into hostme.bitkeeper.com:/ua/repos/j/jfs/linux-2.5

After disabling files that wouldn't build, there were 2 (in-kernel)
modules that referenced _init or _exit code sections when they
shouldn't.

This fixes those modules.

into home.transmeta.com:/home/torvalds/v2.5/linux

into raven.il.steeleye.com:/home/jejb/BK/scsi-for-linus-2.5

into raven.il.steeleye.com:/home/jejb/BK/scsi-for-linus-2.5

into redhat.com:/garz/repo/net-drivers-2.5

into home.transmeta.com:/home/torvalds/v2.5/linux

Certain support files are shared between various ARM machine classes.
In other to sanely support these, we place the shared files in
arch/arm/common instead of the individual machine class directories.

Patch from Russell King <rmk@arm.linux.org.uk>

show_task() attempts to calculate the amount of free space which hasn't been
written to on the kernel stack by reading from the base of the kernel stack
upwards.

However, it mistakenly uses the task_struct pointer as the base of the stack,
which it isn't, and this can cause an oops.

Here is a patch which uses the task thread pointer instead, which should be
located at the bottom of the kernel stack.  It appears this was missed when
the thread structure was introduced.

The recent exit_mmap() changes broke PPC64 when 64-bit applications exec
32-bit ones.  ia32-on-ia64 was broken as well

What is happening is that load_elf_binary() sets TIF_32BIT (via
SET_PERSONALITY) _before_ running exit_mmap().  So when we're unmapping the
vma's of the old image, we are running under the new image's personality.

This causes PPC64 to pass a 32-bit TASK_SIZE to unmap_vmas(), even when the
execing process had a 64-bit image.  Because unmap_vmas() is not provided
with the correct virtual address span it does not unmap all the old image's
vma's and we go BUG_ON(mm->map_count) in exit_mmap().

The early SET_PERSONALITY() is required before we look up the interpreter
because the lookup of the executable has to happen under the alternate root
which SET_PERSONALITY() may set.

Unfortunately this means that we're running flush_old_exec() under the new
exec's personality.  Hence this bug.

So what the patch does is to simply pass ~0UL into unmap_vmas(), which tells
it to unmap everything regardless of current personality.  Which is what the
old open-coded VMA killer was doing.

There remains the problem that some architectures are sometimes passing the
incorrect TASK_SIZE into tlb_finish_mmu().  They've always been doing that.

We cannot clear VM_MAYWRITE in there - it turns writeable MAP_PRIVATE
mappings into readonly ones.

So change it back to the 2.4 form - disallow a writeable MAP_SHARED mapping
against filesystems which do not implement ->writepage().

Patch from: Petr Vandrovec <vandrove@vc.cvut.cz>

soundcore is trying to perform kernel syscalls to load firmware, but falls
afoul of missing `errno'.  Convert it to use VFS API functions.

redo_fd_request() needs to take the queue lock around the call to
elv_next_request().

Patch from "Andres Salomon" <dilinger@voxel.net>

Fix compilation of atyfb_base.c

__wait_on_buffer() needs to use io_schedule(), so processes in there are
accounted as being in I/O wait.

pcmcia timer initialisation fixes from Anton Blanchard

Patch from William Lee Irwin III <wli@holomorphy.com>

PAE's pte_none() and pte_pfn() evaluate their arguments twice;
analogous fixes have been made to other things; c.f. pgtable.h's long
list of one-line inlines with parentheses still around their args.

Patch from: Rusty Russell <rusty@rustcorp.com.au>

Mikael Pettersson points out that "-s" gets mangled to "_s" on the
kernel command line, even though it turns out not to be a
parameter.

Patch from William Lee Irwin III <wli@holomorphy.com>

pgd_index() doesn't parenthesize its argument.  This is a bad idea for
macros, since it's legitimate to pass expressions to them that will get
misinterpreted given operator precedence and the shift.

Patch from Rusty Russell <rusty@rustcorp.com.au>

Make symbol_get() use undefined weak symbols if !CONFIG_MODULE.
Many thanks to RTH for introducing undef weak symbols to me.

Patch from William Lee Irwin III <wli@holomorphy.com>

BLK_BOUNCE_HIGH and BLK_BOUNCE_ANY are compared against 64-bit quantities.
Cast these unsigned long quantities to avoid overflow.

Patch from Manfred Spraul <manfred@colorfullife.com>

cache_alloc_refill() forgets to disable interrupts again on an error path.
This exposes us to slab corruption and it makes slab debugging go BUG (it
expects local irqs to be disabled).

Patch from William Lee Irwin III <wli@holomorphy.com>

struct thread_info is shared with the stack, not struct task_struct.
False positives have been seen.