(With Andrew Morton).

The current dynamic pty allocation scheme has a few problems:

- pty numbers grow to be very large, causing wtmp file bloat.

- Seems to break libc5 and some old applications

So change it to do first-fit.  An IDR tree is used to provide a
logarithmic-time search.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Here is a reworked version of my patch to ext3 to retry certain filesystem
operations after an ENOSPC error.  The ext3_should_retry_alloc() function will
not wait on the currently running transaction if there is a currently active
handle; hence this should avoid deadlocks in the Lustre use case.  The patch
is versus BK-recent.

I've also included a simple, reliable test case which demonstrates the problem
this patch is intended to fix.  (Note that BK-recent is not sufficient to
address this test case, and waiting on the commiting transaction in
ext3_new_block is also not sufficient.  Been there, tried that, didn't work.
We need to do the full-bore retry from the top level.  The
ext3_should_retry_alloc() will only wait on the committing transaction if
there is an active handle; hence Lustre will probably also need to use
ext3_should_retry_alloc() if it wants to reliably avoid this particular
problem.)

#!/bin/sh
#
#
TEST_DIR=/tmp
IMAGE=$TEST_DIR/retry.img
MNTPT=$TEST_DIR/retry.mnt
TEST_SRC=/usr/projects/e2fsprogs/e2fsprogs/build
MKE2FS_OPTS=""
IMAGE_SIZE=8192

umount $MNTPT
dd if=/dev/zero of=$IMAGE bs=4k count=$IMAGE_SIZE
mke2fs -j -F $MKE2FS_OPTS $IMAGE 

function test_log ()
{
	echo $*
	logger -p local4.notice $*
}

mkdir -p $MNTPT
mount -o loop -t ext3 $IMAGE $MNTPT
test_log Retry test: BEGIN
for i in `seq 1 3`
do
	test_log "Retry test: Loop $i"
	echo 2 > /proc/sys/fs/jbd-debug
	while ! mkdir -p $MNTPT/foo/bar
	do
		test_log "Retry test: mkdir failed"
		sleep 1
	done
	echo 0 > /proc/sys/fs/jbd-debug
	cp -r $TEST_SRC $MNTPT/foo/bar 2> /dev/null
	rm -rf $MNTPT/*
done
umount $MNTPT
test_log "Retry test: END"


akpm@osdl.org

  Rework the code to make it a formal JBD API entry point.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

std_resources.{c,h} was only split off due to pc9800 wanting to override it.
With it gone, it might as well be merged back in.  Doesn't change any code.
It was compiled and booted.

This time this also actually doesn't break compilation of any of the
subarches.  That's to say, any further.  I guess it might have been my .config
(my regular PC config, with just the subarch switched through menuconfig) or
O=, but only ELAN actually compiled.  Voyager and VISWS bombed out at the
final link and NUMAQ much sooner (with "physnode_map undeclared" during
compilation of numaq.c).
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Removes more PC9800 code.

Requires:

  bk rm drivers/char/upd4990a.c
  bk rm drivers/net/ne2k_cbus.c
  bk rm drivers/net/ne2k_cbus.h
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

PC9800 sub-arch is incomplete, hackish (at least in IDE), maintainers don't
reply to emails and haven't touched it in awhile.  Can't even config it to
try to build it without other patches to the kernel tree.

bk-rm-script:

#! /bin/sh
bk rm -r ./arch/i386/mach-pc9800
bk rm -r ./arch/i386/boot98
bk rm ./drivers/char/lp_old98.c
bk rm ./drivers/serial/serial98.c
bk rm ./drivers/scsi/scsi_pc98.c
bk rm ./drivers/scsi/pc980155.c
bk rm ./drivers/scsi/pc980155.h
bk rm ./drivers/block/floppy98.c
bk rm ./drivers/input/keyboard/98kbd.c
bk rm ./drivers/input/serio/98kbd-io.c
bk rm ./drivers/input/misc/98spkr.c
bk rm ./drivers/input/mouse/98busmouse.c
bk rm ./drivers/ide/legacy/pc9800.c
bk rm ./drivers/ide/legacy/hd98.c
bk rm -r ./include/asm-i386/mach-pc9800
bk rm ./include/asm-i386/pc9800_sca.h
bk rm ./include/asm-i386/pc9800.h
bk rm ./fs/partitions/nec98.c
bk rm ./fs/partitions/nec98.h
bk rm ./sound/isa/cs423x/pc98.c
bk rm ./sound/isa/cs423x/pc9801_118_magic.h
bk rm ./sound/isa/cs423x/sound_pc9800.h
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

The driver supports the High Precision Event Timer.  The driver has adopted
a similar API to the Real Time Clock driver.  It can support any number of
HPET devices and the maximum number of timers per HPET device.  For further
information look at the documentation in the patch.

Thanks to Venki at Intel for testing the driver on X86 hardware with HPET.

HPET documentation is available at http://www.intel.com/design/chipsets/datashts/252516.htmSigned-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Lower default sizes for POSIX mqueue allocation now that rlimits are in place.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Add a user_struct to the mq_inode_info structure.  Charge the maximum number
of bytes that could be allocated to a mqueue to the user who creates the
mqueue.  This is checked against the per user rlimit.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Add helper function mq_attr_ok() to do mq_attr sanity checking, and do some
extra overlow checking.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Add mq_bytes field to user_struct, and make sure it's properly initialized.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Add an rlimit entry to control the maximum number of bytes a user can allocate
to a POSIX mqueue.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Add simple helper function to grab a reference to a user_struct.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Add sigpending field to user_struct, and make sure it's properly initialized.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

The following patches introduce per user rlimits for both queued signals and
POSIX message queues.  The changes touch all the arches resource.h files as
well as init_task.c to get the rlimit defaults setup.

Both require caching the user_struct to avoid problems with setuid().

The signal changes makes some small changes to send_signal() to pass along the
task being signalled to get proper accounting for signals initiated in
interrupt.  Thanks to Marcelo for getting this one going.


This patch:

Add an rlimit entry to control the maximum number of pending signals a user
may have.  This is essentially just the resource.h changes.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Fix up the i2c code which uses the IDR library.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

There were definately some problems in there.  I've made some changes and
tested with a lot of bounds.  I don't have a machine with enough memory to
fill it up (it would take ~16GB on a 64-bit machine), but I use the "above"
code to simulate a lot of situations.

The problems were:

    * IDR_FULL was not the right value
    * idr_get_new_above() was not defined in the headers or documented.
    * idr_alloc() bug-ed if there was a race and not enough memory was
      allocated.  It should have returned NULL.
    * id will overflow when you go past the end.
    * There was a "(id >= (1 << (layers*IDR_BITS)))" comparison, but at
      the top layer it would overflow the id and be zero.
    * The allocation should return ENOSPC for an "above" value with
      nothing above it, but it returned EAGAIN.

I have not tested on 64-bits (as I don't have a 64-bit machine).

I've included the files, a diff from the previous version, and my test
programs.

For the test programs, idr_test <size> will just attempt to allocate 
<size> elements, check them, free them, and check them again.

idr_test2 <size> <incr> will allocate <size> element with <incr> between
them.

idr_test3 just tests some bounds and tries all values with just a few in
the idr.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

idr_get_new() currently returns an incrementing counter in the top 8 bits of
the counter.  Which means that most users have to mask it off again, and we
only have a 24-bit range.

So remove that counter.  Also:

- Remove the BITS_PER_INT define due to namespace collision risk.

- Make MAX_ID_SHIFT 31, so counters have a 0 to 2G-1 range.

- Why is MAX_ID_SHIFT using sizeof(int) and not sizeof(long)?  If it's for
  consistency across 32- and 64-bit machines, why not just make it "31"?

- Does this still hold true with the counter removed?

/* We can only use half the bits in the top level because there are
   only four possible bits in the top level (5 bits * 4 levels = 25
   bits, but you only use 24 bits in the id). */

  If not, what needs to change?
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

* On a 32-bit architecture, the idr code will cease to work if you add
  more than 2^20 entries.  You will not be able to find many of the
  entries.  The problem is that the IDR code uses 5-bit chunks of the
  number and the lower portion used by IDR is 24 bits, so you have one bit
  that leaks over into the comparisons that should not be there.  The
  solution is to mask off that bit before doing IDR processing.  This
  actually causes the POSIX timer code to crash if you create that many
  timers.  I have included an idr_test.tar.gz file that demonstrates this
  with and without the fix, in case you need more evidence :).

* When the IDR fills up, it returns -1.  However, there was no way to
  check for this condition.  This patch adds the ability to check for the
  idr being full and fixes all the users.  It also fixes a problem in
  fs/super.c where the idr code wasn't checking for -1.

* There was a race condition creating POSIX timers.  The timer was added
  to a task struct for another process then the data for the timer was
  filled out.  The other task could use/destroy time timer as soon as it is
  in the task's queue and the lock is released.  This moves settup up the
  timer data to before the timer is enqueued or (for some data) into the
  lock.

* Change things so that the caller doesn't need to run idr_full() to find
  out the reason for an idr_get_new() failure.

  Just return -ENOSPC if the tree was full, or -EAGAIN if the caller needs
  to re-run idr_pre_get() and try again.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Add data=journal support for reiserfs
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Walking the btree can trigger a number of single block synchronous reads.
This patch does btree readahead during operations that are likely to be long
and sequential.  So far, that only includes directory reads and truncates, but
it can make both much faster.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Remove debugging warning from the reiserfs block allocator code
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

reiserfsck --rebuild-tree expects the only key with a packing locality of 1 to
be for the root directory (key [1 2]).  The new block allocator inherited that
packing locality down to subdirectories, which triggers failures in reiserfsck
--rebuild-tree

reiserfsck in readonly check mode doesn't complain about this, thanks to Jeff
Mahoney for finding it.

The fix is to never inherit packing locality #1
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

From: <mason@suse.com>
From: <jeffm@suse.com>

The current reiserfs allocator pretty much allocates things sequentially
from the start of the disk, it works very nicely for desktop loads but
once you've got more then one proc doing io data files can fragment badly.

One obvious solution is something like ext2's bitmap groups, which puts
file data into different areas of the disk based on which subdirectory
they are in.  The problem with bitmap groups is that if you've got a
group of subdirectories their contents will be spread out all over the
disk, leading to lots of seeks during a sequential read.

This allocator patch uses the packing locality to determine which bitmap
group to allocate from, but when you create a file it looks in the bitmaps
to see how 'full' that packing locality already is.  If it hasn't been
heavily used yet, the packing locality is inherited from the parent
directory putting files in new subdirs close to the parent subdir,
otherwise it is the inode number of the parent directory putting new
files far away from the parent subdir.

The end result is fewer bitmap groups for the same working set.  For
example, one test data set created by 20 procs running in parallel has
6822 subdirs.  And with vanilla reiserfs that would mean 6822
packing localities.  This patch turns that into 26 packing localities.

This makes sequential reads of big directory trees more efficient, but
it also makes the btree more efficient in general.  Things end up sorted
better because groups of subdirs end up with similar keys in the btree,
instead of being spread out all over.

The bitmap grouping code tries to use the start of each bitmap group
for metadata, and offsets the data slightly.  The data and metadata
are still close together, but not completely intermixed like they are
in the default allocator.  The end result is that leaf nodes tend to be
close to each other, making metadata readahead more effective.

The old block allocator had the ability to enforce a minimum
allocation size, but did not use it.  It now tries to do a pass looking
for larger allocation chunks before falling back to the old behaviour
of taking any blocks it can find.

The patch changes the defaults to:

mount -o alloc=skip_busy:dirid_groups:packing_groups

You can get back the old behaviour with mount -o alloc=skip_busy

mount -o alloc=dirid_groups will turn on the bitmap groups
mount -o alloc=packing_groups turns on the packing locality reduction code
mount -o alloc=skip_busy:dirid_groups turns on both dirid_groups and
skip_busy

Finally the patch adds a mount -o alloc=oid_groups, which puts files into
bitmap groups based on a hash of their objectid.  This would be used for
databases or other situations where you have a limited number of very
large files.

This command will tell you how many packing localities are actually in
use:

debugreiserfs -d /dev/xxx | grep '^|.*SD' | sed 's/^.....//' | awk '{print $1}' | sort -u | wc -l
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

The pgalloc.h changes broke ppc64:

In file included from include/asm-generic/tlb.h:18,
                 from include/asm/tlb.h:24,
                 from arch/ppc64/mm/hash_utils.c:48:
include/asm/pgalloc.h: In function `__pte_free_tlb':
include/asm/pgalloc.h:110: dereferencing pointer to incomplete type
include/asm/pgalloc.h:111: dereferencing pointer to incomplete type

Uninlining __pte_free_tlb() fixes that.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

This patch cleans up needless includes of asm/pgalloc.h from the arch/i386/
subtree.  Compile tested on x86_pc SMP.

[I also tried VISWS + SMP without PM doesn't build in smpboot.c,
 though I don't believe its caused by this patch.  With PM, fails
 to link complaining maxcpus is undefined.  Therefore, I presume
 VISWS + SMP is an invalid configuration.]

This patch is part of a larger patch aiming towards getting the include of
asm/pgtable.h out of linux/mm.h, so that asm/pgtable.h can sanely get at
things like mm_struct and friends.

I suggest testing in -mm for a while to ensure there aren't any hidden arch
issues.

The outstanding list of files for other architectures can be found
at http://www.arm.linux.org.uk/misc/pgalloc.txtSigned-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

This patch cleans up needless includes of asm/pgalloc.h from the drivers/
subtree.  drivers/char/mem.c has been compile tested; the others have not,
since they are for non-x86 and non-ARM architectures.

This patch is part of a larger patch aiming towards getting the include of
asm/pgtable.h out of linux/mm.h, so that asm/pgtable.h can sanely get at
things like mm_struct and friends.

I suggest testing in -mm for a while to ensure there aren't any hidden arch
issues.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

This patch cleans up needless includes of asm/pgalloc.h from the fs/
kernel/ and mm/ subtrees.  Compile tested on multiple ARM platforms, and
x86, this patch appears safe.

This patch is part of a larger patch aiming towards getting the include of
asm/pgtable.h out of linux/mm.h, so that asm/pgtable.h can sanely get at
things like mm_struct and friends.

I suggest testing in -mm for a while to ensure there aren't any hidden arch
issues.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

This patch allows for misc binaries to run with credentials and security
token that are calculated according to the binaries, and not according to the
interpreter, which is the legacy behavior of binfmt_misc.

The way it is done is by calling prepare_binprm, which is where these
attributes are calculated, before switching the 'file' field in the bprm from
the binary to the interpreter.

This feature should be used with care, since the interpreter will have root
permissions when running a setuid binary owned by root.

Please note -

- Only root can register an interpreter with binfmt_misc.  The feature is
  documented and the administrator is advised to handle it with care

- The new feature is enabled only with a special flag in the registration
  string.  When this flag is not specified the current behavior of
  binfmt_misc is kept

- This is the only 'right' way for an interpreter to know the correct
  AT_SECURE value for the interpreted binary


From: Chris Wright <chrisw@osdl.org>

  This patchset looks OK, except for one problem.  It installs the fd (which
  could've been unreadable) without unsharing the ->files.  So someone can use
  this to read unreadable yet executable files.  Here's a patch which fixes
  that up.  I added one bit that's commented out because I'm not positive if a
  final steal_locks() is needed.

  I did a fair amount of rearranging to simplify the error conditions
  relative to the fd_install(), and unshare_files().

From: Chris Wright <chrisw@osdl.org>

  I found that the intel patchset (and mine as well) leaked i_writecount on
  the original executed file.  In addition, I verified that the steal_locks()
  bit is indeed needed.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

<background>

I work in a group that works on enabling the IA-32 Execution Layer
(http://www.intel.com/pressroom/archive/releases/20040113comp.htm) on Linux.
In a few words - this is a dynamic translator for IA-32 binaries on IPF
platform.  Following David Mosberger's advice - we use the binfmt_misc
mechanism for the invocation of the translator whenever the user tries to
exec an IA-32 binary.

The EL is meant to help in the migration path from IA-32 to IPF.  From our
beta customers we learnt that at first stage - they tend to keep their
environment mostly intact, using the legacy IA-32 binaries.

Such an environment has, naturally, setuid and non-readable binaries.  It
will be useless to ask the administrator to change the settings of such an
environment - some of them are very complex, and the administrators are
reluctant to make any changes in a system that already proved itself to be
robust and secure.  So, our target with these patches is not to enhance the
support for scripts but rather to allow a translator to be integrated into a
working environment that is not (and should not be) aware to the fact it's
being emulated.

As I said before - it is practically hopeless to expect an administrator of
such a system to change it so that it will suit the current behavior of
binfmt_misc.  But, even if we could do that,

I'm not sure it would be a good idea - these changes are likely to be less
secure than the suggested patches -

- In order to execute non-readable binaries the binary will have to be made
  readable, which is obviously less secure than allowing only a trusted
  translator to read it

- There will be no way for the translator to calculate the accurate
  AT_SECURE value for the translated process.  This might end up with the
  translated process running in a non-secured mode when it actually needs to
  be secured.

</background>


I prepared a patch that solves a couple of problems that interpreters have
when invoked via binfmt_misc.  currently -

1) such interpreters cannot open non-readable binaries

2) the processes will have their credentials and security attributes
   calculated according to interpreter permissions and not those of the
   original binary

the proposed patch solves these problems by -

1) opening the binary on behalf of the interpreter and passing its fd
   instead of the path as argv[1] to the interpreter

2) calling prepare_binprm with the file struct of the binary and not the
   one of the interpreter

The new functionality is enabled by adding a special flag to the registration
string.  If this flag is not added then old behavior is not changed.

A preliminary version of this patch was sent to the list on 9/1/2003 with the
title "[PATCH]: non-readable binaries - binfmt_misc 2.6.0-test4".  This new
version fixes the concerns that were raised by the patch, except of calling
unshare_files() before allocating a new fd.  this is because this feature did
not enter 2.6 yet.


Arun Sharma <arun.sharma@intel.com> says:

We were going through an internal review of this patch:

http://marc.theaimsgroup.com/?l=linux-kernel&m=107424598901720&w=2

which is in your tree already.  I'm not sure if this line of code got
sufficient review.

+               /* call prepare_binprm before switching to interpreter's file
+                * so that all security calculation will be done according to
+                * binary and not interpreter */
+               retval = prepare_binprm(bprm);

The case that concerns me is: unprivileged interpreter and a privileged
binary.  One can use binfmt_misc to execute untrusted code (interpreter) with
elevated privileges.  One could argue that all binfmt_misc interpreters are
trusted, because only root can register them.  But that's a change from the
traditional behavior of binfmt_misc (and binfmt_script).


(Update):

Arun pointed out that calculating the process credentials according to the
binary that needs to be translated is a bit risky, since it requires the
administrator to pay extra attention not to register an interpreter which is
not intended to run with root credentials.

After discussing this issue with him, I would like to propose a modified
patch: The old patch did 2 things - 1) open the binary for reading and 2)
calculate the credentials according to the binary.

I removed the riskier part of changing the credentials calculation, so the
revised patch only opens the binary for reading.  It also includes few words
of warning in the description of the 'open-binary' feature in
binfmt_misc.txt, and makes the function entry_status print the flags in use.

As for the 'credentials' part of the patch, I will prepare a separate patch
for it and send it again to the LKML, describe the problem and ask for people
comments.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Add myself as the PPC4xx maintainer. Merge CREDITS entry from 2.4
Signed-off-by: Matt Porter <mporter@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

/proc/cmdline is filled via an OS400 call iSeries_init().  It scans the
returned data from the end, instead of the beginning.  This leads to
multiple lines in /proc/cmdline

Just scan from the beginning and stop at the first newline.  This patch
changes also the /proc/iSeries/mf/*/cmdline interface to do the same as the
initial setup.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2.6.7-rc3-mm1 changed cpumask_t from ulong to a struct, causing
compile-time errors in arch/ppc/kernel/irq.c.

Proposed fix below. Tested on a G3.
Signed-off-by: Mikael Pettersson <mikpe@csd.uu.se>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Here is both a GNU style and BK patch for adding support for the e500 core and
85xx platform to 2.6.  This is pretty much a direct port from 2.4 with a bit
of cleanup around the edges.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Test for pte_young before going to the costlier atomic test_and_clear, as
asm-generic does.  Test for pte_dirty before going to the costlier atomic
test_and_clear, as asm-generic does (I said before that I would not do so for
pte_dirty, but was missing the point: there is nothing atomic about deciding
to do nothing).  But I've not touched the rather different ppc and ppc64.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Traditionally we've not flushed TLB after clearing the young/referenced bit,
it has seemed just a waste of time.  Russell King points out that on some
architectures, with the move from 2.4 mm sweeping to 2.6 rmap, this may be a
serious omission: very frequently referenced pages never re-marked young, and
the worst choices made for unmapping.

So, replace ptep_test_and_clear_young by ptep_clear_flush_young throughout
rmap.c.  Originally I'd imagined making some kind of TLB gather optimization,
but don't see what now: whether worth it rather depends on how common
cross-cpu flushes are, and whether global or not.

ppc and ppc64 have already found this issue, and worked around it by arranging
TLB flush from their ptep_test_and_clear_young: with the aid of pgtable rmap
pointers.  I'm hoping ptep_clear_flush_young will allow ppc and ppc64 to
remove that special code, but won't change them myself.

It's worth noting that it is Andrea's anon_vma rmap which makes the vma
available for ptep_clear_flush_young in page_referenced_one: anonmm and
pte_chains would both need an additional find_vma for that.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

From: Ivan Kokshaysky <ink@jurassic.park.msu.ru>

Compilation fails due to incorrect usage of NODE_DATA().

Reported by hpa.

This rewrites the PPC64 exception entry/exit routines to make them
smaller and faster.

In particular we no longer save all of the registers for the common
exceptions - system calls, hardware interrupts and decrementer (timer)
interrupts - only the volatile registers.  The other registers are saved
and restored (if used) by the C functions we call.  This involved
changing the registers we use in early exception processing from r20-r23
to r9-r12, which ended up changing quite a lot of code in head.S. 
Overall this gives us about a 20% reduction in null syscall time. 

Some system calls need all the registers (e.g.  fork/clone/vfork and
[rt_]sigsuspend).  For these the syscall dispatch code calls a stub that
saves the nonvolatile registers before calling the real handler.

This also implements the force_successful_syscall_return() thing for
ppc64.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

This implements CONFIG_PREEMPT for ppc64.  Aside from the entry.S
changes to check the _TIF_NEED_RESCHED bit when returning from an
exception, there are various changes to make the ppc64-specific code
preempt-safe, mostly adding preempt_enable/disable or get_cpu/put_cpu
calls where needed.  I have been using this on my desktop G5 for the
last week without problems.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

into kernel.bkbits.net:/home/davem/sparc-2.6