.. and unwind properly to avoid leaks

which is needed to keep track of process usage counts correctly and
efficiently.

Bill Irwin was talking about hw_interrupt_type.set_affinity and kirq.
When I went looking, I failed to find this initialization.

Here are some nice, easy-to-find, named initializers.

We're calling mmdrop() under spin_lock_irq(&rq->lock).  But mmdrop
calls vfree(), which calls smp_call_function().

It is not legal to call smp_call_function() with irq's off.  Because
another CPU may be running smp_call_function() against _this_ CPU, which
deadlocks.

So the patch arranges for mmdrop() to not be called under
spin_lock_irq(&rq->lock).

We are leaving local interrupts disabled coming out of exit_notify().

But we are about to call wait_task_inactive() which spins, waiting for
another CPU to end a task.  If that CPU has issued smp_call_function() to
this CPU, deadlock.

So the patch enables interrupts again before returning from exit_notify().

Also, exit_notify() returns with preemption disabled, so there is no
need to perform another preempt_disable() in do_exit().

Manifested as X profile appearing as /dev/mem ...

This potentially helps debugging, since otherwise a double fault
would generate a triple fault and then reboot the machine. Now
instead it can print out a note about where the problem happened,
unless all the kernel data structures are truly buggered.

it's a noop in 2.5 now that the behvaiour of implicitly exporting
all symbols is gone.

This patch removes the devfs interface code in mtrr that has been
stubbed out by an ifdef forever.  It's one of the few remaining users
of regular files on devfs so there's some urge for me to get rid of it :)

Use cdevname instead in the serial driver printk cut & pasted into about
a dozend places.

small updates to bring us nearer the lm_Sensors CVS (docs, comments,
missing statics, named initializers).  I still need to review their
actual code changes before submitting those..

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

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

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

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

into kernel.bkbits.net:/home/davem/sparc-2.5

into kernel.bkbits.net:/home/davem/sparc-2.5

into kernel.bkbits.net:/home/davem/net-2.5

into kanga.twiddle.net:/home/rth/linux/axp-2.5

the number of metadata buffers. Use the same techniques as the
regular linux buffer cache here.

use more hash buckets for holding xfs metadata, and use the same
hash algorithm as the regular buffer cache.

SGI Modid: 2.5.x-xfs:slinx:139997a

SGI Modid: 2.5.x-xfs:slinx:139992a

SGI Modid: 2.5.x-xfs:slinx:139854a

this was always there, but exposed by the last change in
this area and made much more likely.

SGI Modid: 2.5.x-xfs:slinx:139655a