cm206 switched to use of gendisk, failure path in module_init cleaned up

cdu31a switched to use of gendisk

pcd switched to use of gendisk

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

into samba.org:/scratch/anton/linux-2.5_ppc64

into samba.org:/scratch/anton/linux-2.5_ppc64

into samba.org:/scratch/anton/linux-2.5_ppc64_new

into samba.org:/scratch/anton/linux-2.5_ppc64_new

into samba.org:/scratch/anton/linux-2.5_ppc64_Makefilecleanup

into samba.org:/scratch/anton/linux-2.5_ppc64_Makefilecleanup

into samba.org:/scratch/anton/linux-2.5_ppc64_new

into samba.org:/scratch/anton/linux-2.5_ppc64_new

into samba.org:/scratch/anton/linux-2.5_ppc64

into samba.org:/scratch/anton/linux-2.5_ppc64_Makefilecleanup

into samba.org:/scratch/anton/linux-2.5_ppc64_Makefilecleanup

into samba.org:/scratch/anton/linux-2.5_ppc64_new

into samba.org:/scratch/anton/linux-2.5_ppc64_new

into samba.org:/scratch/anton/linux-2.5_ppc64

the attached patch (against BK-curr) fixes a bug in the new PID allocator,
which bug can cause incorrect hashing of the PID structure which causes
infinite loops in find_pid(). [and potentially other problems.]

into samba.org:/scratch/anton/linux-2.5_ppc64_new

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

Patch from Rohit Seth: allow hugetlb pages to be allocated from the
highmem zone.

From Marcus Alanen <maalanen@ra.abo.fi>

Don't retake the zone lock after spilling a batch of pages into the
buddy.

Instead, just clear local variable `zone' to indicate that no lock is
held.

This is actually a common case - whenever release_pages() is called
with exactly 16 pages (truncate, page reclaim..) Marcus' patch will
save a lock and an unlock.

Also, remove some lock-avoidance heuristics in
pagevec_deactivate_inactive(): the caller has already made these
checks, and the chance of the check here actually doing anything useful
is negligible.

- Spell Jeremy's name correctly.

- Fix compile warning in raw.c

- Do a waitqueue_active() test before waking klogd in printk.

  Not only is is negligibly faster, but the wake_up() in there causes
  deadlocks when you try to print debug info out from inside scheduler
  code.

  This patch gives a delightfully obscure way of avoiding the
  deadlock: kill off klogd.

- Fix a couple of compile warnings in the mtrr code.

From Christoph Hellwig, acked by Jens.

- remove some unneeded runtime initializers.

- remove the explicit call to hd_init() - it already goes through
module_init(), so we're currently running hd_init() twice.

From Christoph Hellwig, acked by Rohit.

- fix config.in description: we know we're on i386 and we also know
that a feature can only be enabled if the hw supports it, the code
alone is not enough

- the sysctl is VM-releated, so move it from /proc/sys/kernel tp
/proc/sys/vm

- adopt to standard sysctl names

From Christoph Hellwig.

There are no lock_kernel() calls in mm/

From Hubertus Franke.

The MAP_LOCKED flag to mmap() currently does nothing.  Hubertus' patch
fixes it so that the relevant mapping is locked into memory, if the
called has CAP_IPC_LOCK.

Somebody somewhere is stomping on PF_NOWARN, and page allocation
failure warnings are coming out of the wrong places.

So change the handling of current->flags to be:

int pf_flags = current->flags;

current->flags |= PF_NOWARN;
...
current->flags = pf_flags;

which is a generally more robust approach.

- writev currently returns -EFAULT if _any_ of the segments has an
invalid address.  We should only return -EFAULT if the first segment
has a bad address.

If some of the first segments have valid addresses we need to write
them and return a partial result.

- The current code only checks if the sum-of-lengths is negative.  If
individual segments have a negative length but the result is positive
we miss that.

So rework the code to detect this, and to be immune to odd wrapping
situations.

As a bonus, we save one pass across the iovec.

- ditto for readv.

The check for "does any segment have a negative length" has already
been performed in do_readv_writev(), but it's basically free here, and
we need to do it for generic_file_read/write anyway.

This all means that the iov_length() function is unsafe because of
wrap/overflow isues.  It should only be used after the
generic_file_read/write or do_readv_writev() checking has been
performed.  Its callers have been reviewed and they are OK.

The code now passes LTP testing and has been QA'd by Janet's team.

A patch from Hirokazu Takahashi to speed up the new sped-up writev
code.

Instead of running ->prepare_write/->commit_write for each individual
segment, we walk the segments between prepage and commit.  So
potentially much larger amounts of data are passed to commit_write(),
and prepare_write() is called much less often.

Added bonus: the segment walk happens inside the kmap_atomic(), so we
run kmap_atomic() once per page, not once per segment.

We've demonstrated a speedup of over 3x.  This is writing 1024-segment
iovecs where the individual segments have an average length of 24
bytes, which is a favourable case for this patch.

Silly bug which was halving swapout bandwidth: we've taken a copy of
page->mapping into a local convenience variable, but forgot to update
that local after adding the page to swapcache.