tmpfs 1/5 swapoff deadlock: my igrab/iput around the yield in
shmem_unuse_inode was rubbish, seems my testing never really hit the
case until last week, when truncation of course deadlocked on the page
held locked across the iput (at least I had the foresight to say "ugh!"
there).  Don't yield here, switch over to the simple backoff I'd been
using for months in the loopable tmpfs patch (yes, it could loop
indefinitely for memory, that's already an issue to be dealt with
later).  The return convention from shmem_unuse to try_to_unuse is
inelegant (commented at both ends), but effective.

From Badari Pavlati.

Use bio_add_page() in direct-io.c.

Patch from Rik adds "I/O wait" statistics to /proc/stat.

This allows us to determine how much system time is being spent
awaiting IO completion.  This is an important statistic, as it tends to
directly subtract from job completion time.

procps-2.0.9 is OK with this, but doesn't report it.

Tells us how many pages were reclaimed by kswapd.

The `pgsteal' statistic tells us how many pages were reclaimed
altogether.  So

	kswapd_steal - pgsteal

is the number of pages which were directly reclaimed by page allocating
processes.


Also, the `pgscan' data is currently counting the number of pages
scanned in shrink_cache() plus the number of pages scanned in
refill_inactive_zone().  These are rather separate concepts, so I
created the new `pgrefill' counter for refill_inactive_zone().
`pgscan' is now just the number of pages scanned in shrink_cache().

Moves the VM accounting out of /proc/stat and into /proc/vmstat.

The VM accounting is now per-cpu.

It also moves kstat.pgpgin and kstat.pgpgout into /proc/vmstat.
Which is a bit of a duplication of /proc/diskstats (SARD), but it's
easy, super-cheap and makes life a lot easier for all the system
monitoring applications which we just broke.

We now require procps 2.0.9.

Updated versions of top and vmstat are available at http://surriel.com
and the Cygnus CVS is uptodate for these changes.  (Rik has the CVS
info at the above site).

This tidies up kernel_stat quite a lot - it now only contains CPU
things (interrupts and CPU loads) and disk things.  So we now have:

/proc/stat:	CPU things and disk things
/proc/vmstat:	VM things	(plus pgpgin, pgpgout)

The SARD patch removes the disk things from /proc/stat as well.

Rewrite these functions to use gang lookup.

- This probably has similar performance to the old code in the common case.

- It will be vastly quicker than current code for the worst case
  (single-page truncate).

- invalidate_inode_pages() has been changed.  It used to use
  page_count(page) as the "is it mapped into pagetables" heuristic.  It
  now uses the (page->pte.direct != 0) heuristic.

- Removes the worst cause of scheduling latency in the kernel.

- It's a big code cleanup.

- invalidate_inode_pages() has been changed to take an address_space
  *, not an inode *.

- the maximum hold times for mapping->page_lock are enormously reduced,
  making it quite feasible to turn this into an irq-safe lock.  Which, it
  seems, is a requirement for sane AIO<->direct-io integration, as well
  as possibly other AIO things.

(Thanks Hugh for fixing a bug in this one as well).

(Christoph added some stuff too)

Adds a gang lookup facility to radix trees.  It provides an efficient
means of locating a bunch of pages starting at a particular offset.

The implementation is a bit dumb, but is efficient enough.  And it is
amenable to the `tagged lookup' extension which is proving tricky to
write, but which will allow the dirty pages within a mapping to be
located in pgoff_t order.

Thanks are due to Huch Dickins for finding and fixing an unpleasant bug
in here.

Pages with no reverse mapping can be present in page tables as a result
of a driver performing remap_page_range().  Don't go BUG over them.

Patch from Hugh Dickins

Our earlier fix for mprotect_fixup was broken - passing an
already-freed VMA to change_protection().

sys_ioperm() is calling kmalloc(GFP_KERNEL) inside get_cpu().  That's
wrong, because the memory allocation could schedule away and return on
a different CPU.

So change it to perform the memory allocation outside the atomic region.

- hugetlb Documentation update

- Add /proc/buddyinfo documentation

- nano-cleanup in __remove_from_page_cache.

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

into mulgrave.(none):/home/jejb/BK/scsi-for-linus-2.5

Hi!

Since the introduction of USER_HZ the SG_[GS]ET_TIMEOUT ioctls may have
a serious BUG as userspace uses a different HZ from the HZ in kernelspace.

In x86 HZ=1000 and USER_HZ=100, resulting in confusing timouts as the
kernel measures time 10 times as fast as userspace.

This patch is an attempt to fix this by transforming USER_HZ based timing to
HZ based timing before storing it in timeout. To make sure that SG_GET_TIMEOUT
and SG_SET_TIMEOUT behave consistently a field timeout_user is added which
stores the exact value that's passed by SG_SET_TIMEOUT and it's returned on
SG_GET_TIMEOUT.

Rolf Fokkens
fokkensr@fokkensr.vertis.nl

P.S. this is the second post of this patch

But it's called from scsi_add_lun()->scsi_alloc_sdev() before the type
is known.  The type is -1 all the time in scsi_initialise_merge_fn()
and scsi always bounces.

This patch makes it do the right thing - just enable block-highmem for
all scsi devices.

Jens had this to say:

"I guess that block-highmem has been around long enough, that I can
 use the term 'historically' at least in the kernel sense :-)

 This extra check was added for IDE because each device type driver
 (ide-disk, ide-cd, etc) needed to be updated to not assume virtual
 mappings of request data was valid.  I only did that for ide-disk,
 since this is the only one where bounce buffering really hurt
 performance wise.  So while ide-cd and ide-tape etc could have been
 updated, I deemed it uninteresting and not worthwhile.

 Now, this was just carried straight into the scsi counter parts,
 conveniently, because of laziness.  A quick glance at sr shows that it
 too can aviod bouncing easily (no changes needed).  st may need some
 changes, though.  So again, for scsi it was a matter of not impacting
 existing code in 2.4 too much.

 So TYPE_DISK check can be killed in 2.5 if someone does the work of
 checking that it is safe.  I'm not so sure it will make eg your SCSI
 CD-ROM that much faster :-)"

This removes an unused label in fs/devfs/base.c

into kroah.com:/home/greg/linux/BK/gregkh-2.5

It needs s/malloc.h/slab.h/ .
It also forgets to free some memory on an error exit patch.
Patch for 2.5.39 follows.

Here are the scatterlist primitives there's been mail about before.
Now the code has passed basic sanity testing, and is ready to merge
into Linus' tree to start getting wider use.  Greg, please merge!

To recap, the routines are a utility layer packaging several usb
core facilities to improve system performance.  It's synchronous.
The code uses functionality that drivers could use already, but
generally haven't:

    - Request queueing.  This is a big performance win.  It lets
      device drivers help the hcds avoid wasted i/o bandwidth, by
      eliminating irq and scheduling latencies between requests.  It
      can make a huge difference at high speed, when the latencies
      often exceed the time to handle each i/o request!

    - The new usb_map_sg() primitives, leveraging IOMMU hardware
      if it's there (better than entry-at-a-time mapping).

    - URB_NO_INTERRUPT transfer flag, a hint to hcds that they
      can avoid a 'success irq' for this urb.  Only the urb for
      the last scatterlist entry really needs an IRQ, the others
      can be eliminated or delayed.  (OHCI uses this today, and
      any HCD can safely ignore it.)

The particular functionality in these APIs seemed to meet Matt's
requirements for usb-storage, so I'd hope the 2.5 usb-storage
code will start to use these routines in a while.  (And maybe
those two scanner drivers: hpusbscsi, microtek.)

Brief summary of testing:  this code seems correct for normal
reads and writes, but the fault paths (including cancelation)
haven't been tested yet.  Both EHCI and OHCI seem to be mostly
OK with these more aggressive queued loads, but may need small
updates (like the two I sent yesterday).  Unfortunately I have
to report that UHCI and urb queueing will sometimes lock up my
hardware (PIIX4), so while we're lots better than 2.4 this is
still a bit of a trouble spot for now.

I'll be making some testing software available shortly, which
will help track down remaining HCD level problems by giving the
queuing APIs (and some others!) a more strenuous workout than
most drivers will, in their day-to-day usage.

- Dave

Greg, attached is a patch designed for diagnostic purposes.  Please apply
to the 2.5 tree -- yes, we'll be removing this at some point in the future.

It appears that we have a problem clearing halts.  This patch causes a very
clear message to be printed whenever a usb_stor_clear_halt() manages to
work.  So far, I haven't seen such a thing happen.  And I've seen _lots_ of
STALL conditions.

This problem has likely been around for a while... however, it hasn't been
noticed before because usb-storage was difficult to use because of other
bugs.  Heck, the most recent 'bk pull' is the first one for me in _months_
which let me boot all the way into X11.

I'm going to hold my patch queue until this is resolved.  On my test setup,
it's easy to see this failing.  I've tried with 4 different devices, with
both UHCI and EHCI drivers.  I don't want to confuse this problem with
other patches...

'result' in this function always seems to be -32.  Which is odd, because
control endpoints shouldn't do that.

I'm open to suggestions as to where to look for this bug, but my instincts
are telling me that this is a core or HCD issue, not a usb-storage issue.

On a positive note, this means that the error-recovery system gets a good
workout.

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

into flint.arm.linux.org.uk:/usr/src/linux-bk-2.5/linux-2.5-rmk

This corrects spelling mistakes, adds missed configuration for
cpufreq, corrects free_irq comment, etc.

Add "IRQ_" prefix to these sa1111 irq numbers.

We must clear down all currently pending IRQs before servicing any
IRQ on the chip.  This prevents immediate recursion into the
interrupt handling paths when we service the first IRQ.

This cset updates sa1100 code for the now merged cpufreq next-gen.

Update sa1100fb for recent fbcon changes, and move stork LCD power
handling into machine specific file.

This didn't follow the LDM model correctly.  The SA1111 is always
a device on the root bus.

This cset updates the SA1111 core, PCMCIA, OHCI and keyboard drivers,
allowing them to take advantage of the Linux device manager code;
this implements initial suspend/resume support for the SA1111 in the
core.  Many existing drivers currently rely on the old PM-based
interface for suspend/resume support.

In a test where some memory corruption happened, I noticed an
oops (null pointer exception in_irq) that's avoidable.  Here's
a patch that avoids it ... anyone seeing the err() is likely
to hang some process, but that's better than the alternative.
(Also inlines some used-once routines, saving a bit of space
to make up for the new diagnostic.)

In doing some more extensive testing of the urb queueing behavior,
I noticed that (a) IOC wasn't always being set for each urb, while
for now it needs to be set; (b) a qh patchup wasn't done quite
where it should be.  This resolves those two issues, as well
as making it a bit less noisy to unlink lots of urbs at the once.

This has minor usbcore cleanups:

DOC:
    - the changes passing a usb_interface to driver probe() and disconnect()
      weren't reflected in their adjacent docs.  likewise they still said
      it was possible to get a null usb_device_id (no more).

    - the (root) hub API restrictions from rmk's ARM patch weren't
      flagged

    - mention the non-dma-coherent cache issue for usb_buffer_alloc()

    - mention disconnect() cleanup issue with usb_{control,bulk}_msg()
      [ you can't cancel those urbs from disconnect() ]

CODE
    - make driver ioctl() use 'usb_interface' too ... this update
      also resolves an old 'one instance per device' bad assumption

    - module locking on driver->ioctl() was goofy, kept BKL way too
      long and didn't try_inc_mod_count() like the rest of usbcore

    - hcd unlink code treated iso inappropriately like interrupt;
      only interrupt still wants that automagic mode

    - move iso init out of ohci into shared submit_urb logic

    - remove interrupt transfer length restriction; hcds that don't
      handle packetization (just like bulk :) should be updated,
      but device drivers won't care for now.