From: Paul Jackson <pj@sgi.com>

I've read over the code in each case, built and ran a test case for i386 in
particular, and studied the other uses and definitions of
test_and_change_bit().  Everything I see recommends this change.

- Fix test_and_change_bit() comment: returns old value, not new one.

From: Max Asbock <masbock@us.ibm.com>

This patch makes serial line registration in the ibmasm service processor
driver depend on CONFIG_SERIAL_8250.  Previously the driver wouldn't
compile when serial driver support wasn't enabled.

From: Evan Felix <evan.felix@pnl.gov>

Here is a patch that fixes a major issue in the raid5/6 code.  It seems
that the code:

logical_sector = bi->bi_sector & ~(STRIPE_SECTORS-1);
(sector_t)     = (sector_t)    & (constant)

that the right side of the & does not get extended correctly when the
constant is promoted to the sector_t type.  I have CONFIG_LBD turned on so
sector_t should be 64bits wide.  This fails to properly mask the value of
4294967296 (2TB/512) to 4294967296.  in my case it was coming out 0.  this
cause the loop following this code to read from 0 to 4294967296 blocks so
it could write one character.

As you might imagine this makes a format of a 3.5TB filesystem take a very
long time.

From: Tony Breeds <tony@bakeyournoodle.com>

From: Tony Breeds <tony@bakeyournoodle.com>

From: Tony Breeds <tony@bakeyournoodle.com>

From: Tony Breeds <tony@bakeyournoodle.com>

From: Bjorn Helgaas <bjorn.helgaas@hp.com>

gen_rtc.c doesn't work on ia64 (we don't have asm/rtc.h, for starters), so
don't offer it there.

From: Herbert Xu <herbert@gondor.apana.org.au>

This patch makes this file includes linux/init.h since it uses the __init
tag.

From: Martin Hicks <mort@bork.org>

I just bought an ASUS TV FM capture card, based on the saa7134 chip.  It only
had one input specified, coax.  This patch adds the Composite and S-Video
inputs.  It seems to work correctly for me.

From: Herbert Xu <herbert@gondor.apana.org.au>

The previous fix causes a syntax error when building:

Working on: /home/gondolin/herbert/src/debian/work/kernel/build/2.6/kernel-source-2.6.5-2.6.5/Documentation/DocBook/parportbook.sgml
jade:/home/gondolin/herbert/src/debian/work/kernel/build/2.6/kernel-source-2.6.5-2.6.5/Documentation/DocBook/parportbook.sgml:4059:2:E: invalid comment declaration: found character "!" outside comment but inside comment declaration
jade:/home/gondolin/herbert/src/debian/work/kernel/build/2.6/kernel-source-2.6.5-2.6.5/Documentation/DocBook/parportbook.sgml:4058:0: comment declaration started here
jade:/home/gondolin/herbert/src/debian/work/kernel/build/2.6/kernel-source-2.6.5-2.6.5/Documentation/DocBook/parportbook.sgml:4059:4:E: character data is not allowed here

This patch removes the offending line completely since that file is probably
not coming back anyway.

From: Geert Uytterhoeven <geert@linux-m68k.org>

I/O port numbers can be larger than 8-bit on many platforms (this caused a
warning when {out,in}b() cast reg to a pointer on platforms with memory
mapped I/O)

From: Geert Uytterhoeven <geert@linux-m68k.org>

Variable error is not initialized, but printed if tty_unregister_driver()
fails.

From: Geert Uytterhoeven <geert@linux-m68k.org>

DVB_TWINHAN_DST depends on DVB_BT8XX (dependency is explicitly mentioned in
help text, but not enforced)

From: Geert Uytterhoeven <geert@linux-m68k.org>

PCI multi-IO card support depends on PCI

From: Geert Uytterhoeven <geert@linux-m68k.org>

Recent serial changes moved some code, causing unused variable warnings.

From: Geert Uytterhoeven <geert@linux-m68k.org>

jiffies must be unsigned long

From: Martin Schwidefsky <schwidefsky@de.ibm.com>

The patch avoids the instantiation of pagetables for not-present pages in
get_user_pages().  Without this, the coredump code can cause total memory
exhaustion in pagetables.  Consider a store to current stack - 1TB.  The
stack vma is extended to include this address because of VM_GROWSDOWN.  If
such a process dies (which is likely for a defunc process) then the elf core
dumper will cause the system to hang because of too many page tables.

We especially recognise this situation and simply return a ref to the zero
page.

From: "Randy.Dunlap" <rddunlap@osdl.org>

From: Michael Still <mikal@stillhq.com>

Correct kernel-doc comment with incorrect parameters documented

From: Pavel Machek <pavel@suse.cz>

If you stop process with ^Z, then suspend, process is awakened.  Thats a
bug.  Solution is to simply leave already stopped processes alone.  Plus we
no longer use TASK_STOPPED for processes in refrigerator.  Userland might
see us and get confused.

From: Pavel Machek <pavel@ucw.cz>

It makes swsusp behave correctly w.r.t.  discontingmem, and adds highmem
handling.

From: Pavel Machek <pavel@ucw.cz>

Bill Irwin did some work on this.  It makes swsusp behave correctly w.r.t. 
discontingmem, and adds highmem handling (very simple-minded, but should work
ok with 1GB).  It now should behave correctly w.r.t.  more than one swap
device, and fixes double restoring of console.

From: Rene Herman <rene.herman@keyaccess.nl>

This patch tries to improve the i386/mach-default probe_roms().  This also
c99ifies the data, adds an IORESOURCE_IO flag for the I/O port resources,
an IORESOURCE_MEM flag for the VRAM resource, IORESOURCE_READONLY |
IORESOURCE_MEM for the ROM resources and adds two additional "adapter ROM
slots" (for a total of 6) since it now also scans the 0xe0000 segment.

From: Rene Herman <rene.herman@keyaccess.nl>

The i386 probe_roms() function has a fair number of problems currently:

- When you actually have an adapter ROM in the machine, your video ROM
  disappears.  This is due to the pc9800 subarch merge that split it up in
  probe_video_rom(int roms) and probe_extension_roms(int roms), but expects a
  "roms++" in probe_video_roms() to have an effect outside of that function.

- The majority of VGA adapters these days host a ROM larger then 32K, yet
  the current code hardcodes a 32K ROM.  The VGA BIOS "length" byte is
  normally valid (it in fact needs to be for a regular mainboard BIOS to
  accept it) and I've verified on a few dozen very new to very old VGAs that
  it is.  However, assuming someone actually did not check for the length and
  checksum there for a reason, the safe thing to do here is accept the length
  byte when we also get a valid checksum.

- The current code scans 0xc0000 to 0xdffff for a video ROM while the
  standard PC thing to do (that which the BIOS does) is only scan for a video
  ROM starting between 0xc0000 and 0xc7fff.  This means that on a headless-
  (or BIOS-less monochrome adapter-) box, the first adapter ROM found
  triggers the registration of a 32K "Video ROM" at hardcoded address
  0xc0000, even when _nothing_ is present between 0xc0000 and 0xc7fff.

- The current adapter ROM scan stops at 0xdffff, whether or not an
  extension ROM is present at 0xe0000.  The PC thing to do is scan 0xc8000
  upto 0xdffff if an extension ROM is present, and upto 0xeffff when it's not
  (it's not/hardly ever).

- Adapter ROMs are called "Extension ROM", but the latter term is really
  better reserved for a motherboard extension ROM.

- Currently, the code happily starts scanning through a ROM it just
  registered looking for the next one (just does += 2048, even when that's
  inside the previous ROM) which is at least silly.

Unfortunately, this code is "subarched" between mach-default and
mach-pc9800, meaning the patch got a bit involved. Currently all this
code, and gobs of data, is defined (not just declared) in the header:

   include/asm-i386/mach-{default,pc9800}/mach_resources.h

which isn't nice. That .h really wants to be a .c. The first patch, in
the next message, does not change any code but only undoes the
probe_video_rom / probe_extension_roms split and moves the code to a new
file

   arch/i386/mach-{default,pc9800}/std_resources.c

with a header

   include/asm-i386/std_resources.h

for the prototypes only. The second patch overhauls the code itself for
mach-default. Please see comments on top of that patch for (yet more)
comments. It's tested on various machines, with and without adapter ROMs.

I haven't touched pc9800. Nothing should have changed though. The pc9800
author, as given in the code, is CCed.

Also, x86-64 inherits the probe_roms() code from 2.4, and while it
doesn't have the subarch specific problems, it has all others. I'll
convert it to if this i386 version is deemed desirable.



This patch doesn't change any code, just moves stuff from the
"mach_resources.h" header to a "std_resources.c" subarch specific file, and
introduces a "std_resources.h" header for the prototypes.

Almost everywhere where JBD removes a buffer from the transaction lists the
caller then nulls out jh->b_transaction.  Sometimes, the caller does that
without holding the locks which are defined to protect b_transaction.  This
makes me queazy.

So change things so that __journal_unfile_buffer() nulls out b_transaction
inside both j_list_lock and jbd_lock_bh_state().

It cleans things up a bit, too.

We're seeing heavy contention against j_list_lock on 8-way in
do_get_write_access().

We actually don't need j_list_lock in there except for one little case - the
per-bh jbd_lock_bh_state() is sufficient to protect this buffer's internal
state.

On some nice quick LVM array Ram Pai measured an overall 3x speedup from this
patch:

the script took the following time on 265mm1
 real    0m57.504s
 user    0m0.400s
 sys     7m29.867s


 and with the 2patches it took
 real 	0m19.983s
 user    0m0.438s
 sys     1m55.896s

From: "Randy.Dunlap" <rddunlap@osdl.org>

From: Anton Blanchard <anton@samba.org>

Directory notify code was showing up in a dd bs=1024k from 2 raid arrays
on an emulex FC adapter:

3635     69.4896  vmlinux-2.6.5            .default_idle
332       6.3468  vmlinux-2.6.5            .__copy_tofrom_user
112       2.1411  vmlinux-2.6.5            .save_remaining_regs
76        1.4529  vmlinux-2.6.5            .scsi_dispatch_cmd
64        1.2235  vmlinux-2.6.5            .dnotify_parent
61        1.1661  vmlinux-2.6.5            .do_generic_mapping_read

We already have a sysctl to enable/disable it, the patch below uses it
in dnotify_parent. dnotify_parent disappears and idle time goes up:

4508     70.8582  vmlinux-2.6.5            .default_idle
253       3.9767  vmlinux-2.6.5            .__copy_tofrom_user
142       2.2320  vmlinux-2.6.5            .save_remaining_regs
88        1.3832  vmlinux-2.6.5            .shrink_zone
84        1.3203  vmlinux-2.6.5            .elx_drvr_unlock
75        1.1789  vmlinux-2.6.5            .scsi_dispatch_cmd
69        1.0846  vmlinux-2.6.5            .do_generic_mapping_read

Of course, to gain this small speedup isers need to know to set
/proc/sys/fs/dir-notify-enable to zero.  Nobody does that.

From: Marcelo Tosatti <marcelo.tosatti@cyclades.com>

The cyclades.c driver was marked BROKEN_ON_SMP during early 2.6.  It was
fixed later on but the tag was left in Kconfig.

The driver is not very smart wrt SMP locking, it can be improved.  There is
only one spinlock per card which guarantees command block ordering and
protects different shared data, which can be held for long periods.

_But_ the locking works reliably, so remove the BROKEN_ON_SMP tag.

From: "Martin J. Bligh" <mbligh@aracnet.com>

I'd prefer we renamed this to page_to_nid() before anyone starts using it. 
This fits with the naming convention of everything else (pfn_to_nid, etc). 
Nobody uses it right now - I grepped the whole tree.

From: Hugh Dickins <hugh@veritas.com>

Some arches refer to page->mapping for their dcache flushing: use
page_mapping(page) for safety, to avoid confusion on anon pages, which will
store a different pointer there - though in most cases flush_dcache_page is
being applied to pagecache pages.

arm has a useful mapping_mapped macro: move that to generic, and add
mapping_writably_mapped, to avoid explicit list_empty checks on i_mmap and
i_mmap_shared in several places.

Very tempted to add page_mapped(page) tests, perhaps along with the
mapping_writably_mapped tests in do_generic_mapping_read and
do_shmem_file_read, to cut down on wasted flush_dcache effort; but the
serialization is not obvious, too unsafe to do in a hurry.

Fix up the rw_swap_page_sync() gorrors by fully decoupling this function
from the VM - it is now just a helper function which reads a page from or
writes a page to swap.

From: Hugh Dickins <hugh@veritas.com>

Tracking anonymous pages by anon_vma,pgoff or mm,address needs a
pointer,offset pair in struct page: mapping,index the natural choice.  But
swapcache uses those for &swapper_space,swp_entry_t.

It's trivial to separate swapcache from pagecache with radix tree; most of
swapper_space is actually unused, just a fiction to pretend swap like file;
and page->private is a good place to keep swp_entry_t, now that swap never
uses bufferheads.

Define PG_anon bit, page_add_rmap SetPageAnon and put an oopsable address in
page->mapping to test that we're not confused by it.  Define
page_mapping(page) macro to give NULL when PageAnon, whatever may be in
page->mapping.  Define PG_swapcache bit, deduce swapper_space from that in
the few places we need it.

add_to_swap_cache now distinct from add_to_page_cache.  Separating the caches
somewhat simplifies the tmpfs swizzling in swap_state.c, now the page can
briefly be in both caches.

The rmap method remains pte chains, no change to that yet.  But one small
functional difference: the use of PageAnon implies that a page truncated
while still mapped will no longer be found and freed (swapped out) by
try_to_unmap, will only be freed by exit or munmap.  But normally pages are
unmapped by vmtruncate: this should only affect nonlinear mappings, and a
later patch not in this batch will fix that.

From: Hugh Dickins <hugh@veritas.com>

First of a batch of three rmap patches: this initial batch of three paving
the way for a move to some form of object-based rmap (probably Andrea's, but
drawing from mine too), and making almost no functional change by itself.  A
few days will intervene before the next batch, to give the struct page
changes in the second patch some exposure before proceeding.

rmap 1 create include/linux/rmap.h

Start small: linux/rmap-locking.h has already gathered some declarations
unrelated to locking, and the rest of the rmap declarations were over in
linux/swap.h: gather them all together in linux/rmap.h, and rename the
pte_chain_lock to rmap_lock.

From: Jens Axboe <axboe@suse.de>

CFQ I/O scheduler

From: Jens Axboe <axboe@suse.de>

There's a small discrepancy in when we decide to unplug a queue based on
q->unplug_thresh.  Basically it doesn't work for tagged queues, since
q->rq.count[READ] + q->rq.count[WRITE] is just the number of allocated
requests, not the number of requests stuck in the io scheduler.  We could
just change the nr_queued == to a nr_queued >=, however that is still
suboptimal.

This patch adds accounting for requests that have been dequeued from the io
scheduler, but not freed yet.  These are q->in_flight.  allocated_requests
- q->in_flight == requests_in_scheduler.  So the condition correctly
becomes

	if (requests_in_scheduler == q->unplug_thresh)

instead.  I did a quick round of testing, and for dbench on a SCSI disk the
number of timer induced unplugs was reduced from 13 to 5 :-).  Not a huge
number, but there might be cases where it's more significant.  Either way,
it gets ->unplug_thresh always right, which the old logic didn't.

From: Neil Brown <neilb@cse.unsw.edu.au>

I've made a bunch of changes to the 'md' bits - largely moving the
unplugging into the individual personalities which know more about which
drives are actually in use.

From: Jens Axboe <axboe@suse.de>

Dog slow software suspend found this one. If WB_SYNC_ALL, then you need
to mark the bio as sync as well.

This is because swap_writepage() does a remove_exclusive_swap_page() (going
to __delete_from_swap_cache -> __remove_from_page_cache) which can kill
page->mapping, thus aops->sync_page() has nothing to work with for unplugging
the address space.

From: Jens Axboe <axboe@suse.de>,
      Chris Mason,
      me, others.

The global unplug list causes horrid spinlock contention on many-disk
many-CPU setups - throughput is worse than halved.

The other problem with the global unplugging is of course that it will cause
the unplugging of queues which are unrelated to the I/O upon which the caller
is about to wait.

So what we do to solve these problems is to remove the global unplug and set
up the infrastructure under which the VFS can tell the block layer to unplug
only those queues which are relevant to the page or buffer_head whcih is
about to be waited upon.

We do this via the very appropriate address_space->backing_dev_info structure.

Most of the complexity is in devicemapper, MD and swapper_space, because for
these backing devices, multiple queues may need to be unplugged to complete a
page/buffer I/O.  In each case we ensure that data structures are in place to
permit us to identify all the lower-level queues which contribute to the
higher-level backing_dev_info.  Each contributing queue is told to unplug in
response to a higher-level unplug.

To simplify things in various places we also introduce the concept of a
"synchronous BIO": it is tagged with BIO_RW_SYNC.  The block layer will
perform an immediate unplug when it sees one of these go past.

From: Joe Thornber <thornber@redhat.com>

dm.c: remove __dm_request (merge with previous patch).