A reworked version of the batched page freeing and lock amortisation
for VMA teardown.

It walks the existing 507-page list in the mmu_gather_t in 16-page
chunks, drops their refcounts in 16-page chunks, and de-LRUs and
frees any resulting zero-count pages in up-to-16 page chunks.

Clean up put_page() and page_cache_release().  It's pretty simple now:

#define page_cache_get(page)           get_page(page)
#define page_cache_release(page)       put_page(page)

it was only being used in invalidate_inode_pages(), and from there,
pagevec_release() does the same thing.

As suggested by Daniel - it's a bug to run put_page_testzero
against a zero-ref page.

please apply this patch (Robert ACK-ed it). While there is a preemptible
kernel entry already, i think listing this at the scheduler entry is
justfied, preemption has a number of scheduler interactions.

this is an updated version of the LDT fixes. It fixes the following kinds
of problems:

 - fix a possible gcc optimization causing a race causing the loading of a
   corrupt LDT descriptor upon context switch. [this fix got simplified
   over previous versions.]

 - remove an unconditional OOM printk, and there's no need to set ->size
   in the OOM path.

 - fix preemption bugs, load_LDT()/clear_LDT() was not preemption-safe,
   when it was used outside of spinlocks.

the context-switch race is the following. 'LDT modification' is the
following operation: the seg->ldt pointer is modified, then seg->size is
modified. In theory gcc is free to reschedule the two modifications, and
first modify ->size, then ->ldt. Thus if this modification is not
synchronized with context-switches, another thread might see a temporary
state of the new ->size [which was increased], but still the old pointer.
Ie.:

	CPU0				CPU1

	pc->size = newsize;
					load_LDT(); // (oldptr, newsize)
	pc->ldt = newptr;

the corrupt LDT is loaded until the SMP cross-call is sent, leaving the
window open for many usecs.

the fix is to put a wmb() after ->ldt modifications. [this is also in
preparation of not-write-ordered SMP x86 designs.]

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

some mainboards (Andrew Morton's Dell) report that even everything
is okay with AUX. Also remove a check for very old AMI i8042's, which
could generate false positives on modern buggy mainboards.

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

jfs_get_blocks should return up to the number of blocks in the
extent rather than limiting itself to one block, as the initial,
trivial implementation did.  This greatly reduces the overhead of
O_DIRECT reads and writes.

Submitted by Badari Pulavarty (pbadari@us.ibm.com)

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

Submitted by Steve Best.

This patch exposes basic allocation statistics for pci pools,
very much like /proc/slabinfo but applying to DMA-consistent
memory.  A file "pools" is created in the driverfs directory
for the relevant pci device when the first pool is created, and
removed when the last pool is destroyed.

Please merge to 2.5.latest.  If it matters, DaveM said it
looks fine.  It produces sane output for all the 2.5.30
USB host controller drivers.

This patch fixes a bug in NUMA-Q PCI code where the kernel can't find PCI
devices on any node other than the first.

sh pci ops changes