The following commits cause a number of regressions:

  commit 58e2d4ca
  Author: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
  Date:   Fri Jan 25 21:08:00 2008 +0100
  sched: group scheduling, change how cpu load is calculated

  commit 6b2d7700
  Author: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
  Date:   Fri Jan 25 21:08:00 2008 +0100
  sched: group scheduler, fix fairness of cpu bandwidth allocation for task groups

Namely:
 - very frequent wakeups on SMP, reported by PowerTop users.
 - cacheline trashing on (large) SMP
 - some latencies larger than 500ms

While there is a mergeable patch to fix the latter, the former issues
are not fixable in a manner suitable for .25 (we're at -rc3 now).

Hence we revert them and try again in v2.6.26.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Tested-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

* 'slab-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/christoph/vm:
  slub: fix possible NULL pointer dereference
  slub: Add kmalloc_large_node() to support kmalloc_node fallback
  slub: look up object from the freelist once
  slub: Fix up comments
  slub: Rearrange #ifdef CONFIG_SLUB_DEBUG in calculate_sizes()
  slub: Remove BUG_ON() from ksize and omit checks for !SLUB_DEBUG
  slub: Use the objsize from the kmem_cache_cpu structure
  slub: Remove useless checks in alloc_debug_processing
  slub: Remove objsize check in kmem_cache_flags()
  slub: rename slab_objects to show_slab_objects
  Revert "unique end pointer" patch
  slab: avoid double initialization & do initialization in 1 place

1. exit_notify() always calls kill_orphaned_pgrp(). This is wrong, we
   should do this only when the whole process exits.

2. exit_notify() uses "current" as "ignored_task", obviously wrong.
   Use ->group_leader instead.

Test case:

	void hup(int sig)
	{
		printf("HUP received\n");
	}

	void *tfunc(void *arg)
	{
		sleep(2);
		printf("sub-thread exited\n");
		return NULL;
	}

	int main(int argc, char *argv[])
	{
		if (!fork()) {
			signal(SIGHUP, hup);
			kill(getpid(), SIGSTOP);
			exit(0);
		}

		pthread_t thr;
		pthread_create(&thr, NULL, tfunc, NULL);

		sleep(1);
		printf("main thread exited\n");
		syscall(__NR_exit, 0);

		return 0;
	}

output:

	main thread exited
	HUP received
	Hangup

With this patch the output is:

	main thread exited
	sub-thread exited
	HUP received
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

p->exit_state != 0 doesn't mean this process is dead, it may have
sub-threads.  Change the code to use "p->exit_state && thread_group_empty(p)"
instead.

Without this patch, ^Z doesn't deliver SIGTSTP to the foreground process
if the main thread has exited.

However, the new check is not perfect either.  There is a window when
exit_notify() drops tasklist and before release_task().  Suppose that
the last (non-leader) thread exits.  This means that entire group exits,
but thread_group_empty() is not true yet.

As Eric pointed out, is_global_init() is wrong as well, but I did not
dare to do other changes.

Just for the record, has_stopped_jobs() is absolutely wrong too.  But we
can't fix it now, we should first fix SIGNAL_STOP_STOPPED issues.

Even with this patch ^Z doesn't play well with the dead main thread.
The task is stopped correctly but do_wait(WSTOPPED) won't see it.  This
is another unrelated issue, will be (hopefully) fixed separately.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Factor out the common code in reparent_thread() and exit_notify().

No functional changes.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Oddly enough, unsigned int c = '\300'; puts a "negative" value in c, not
0300...  This fixes the default unicode compose table by using integers
instead of character constants.
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This patch fix possible NULL pointer dereference if kzalloc
failed. To be able to return proper error code the function
return type is changed to ssize_t (according to callees and
sysfs definitions).
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Christoph Lameter <clameter@sgi.com>

Slub is missing some NUMA support for large kmallocs. Provide that.
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Christoph Lameter <clameter@sgi.com>

We only need to look up object from c->page->freelist once in
__slab_alloc().
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Christoph Lameter <clameter@sgi.com>

Provide comments and fix up various spelling / style issues.
Signed-off-by: Christoph Lameter <clameter@sgi.com>

Group SLUB_DEBUG code together to reduce the number of #ifdefs. Move some
debug checks under the #ifdef.
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Christoph Lameter <clameter@sgi.com>

The BUG_ONs are useless since the pointer derefs will lead to
NULL deref errors anyways. Some of the checks are not necessary
if no debugging is possible.
Signed-off-by: Christoph Lameter <clameter@sgi.com>

No need to access the kmem_cache structure. We have the same value
in kmem_cache_cpu.
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Christoph Lameter <clameter@sgi.com>

Alloc debug processing is never called with a NULL object pointer.
No reason to check for NULL.
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Christoph Lameter <clameter@sgi.com>

There is no page->offset anymore and also no associated limit on the number
of objects. The page->offset field was removed for 2.6.24. So the check
in kmem_cache_flags() is now also obsolete (should have been dropped
earlier, somehow a hunk vanished).
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-by: Christoph Lameter <clameter@sgi.com>

The sysfs callback is better named show_slab_objects since it is always
called from the xxx_show callbacks. We need the name for other purposes
later.
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Christoph Lameter <clameter@sgi.com>

This only made sense for the alternate fastpath which was reverted last week.

Mathieu is working on a new version that addresses the fastpath issues but that
new code first needs to go through mm and it is not clear if we need the
unique end pointers with his new scheme.
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Christoph Lameter <clameter@sgi.com>

* 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm:
  [ARM] Fix freeing of page tables for ARM in free_pgd_slow

Fix docbook problems in fusion source files.
These cause the generated docbook to be incorrect.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix docbook problems in kernel-api.tmpl.
These cause the generated docbook to be incorrect.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix docbook problems in USB source files.
These cause the generated docbook to be incorrect.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix docbook problem in SCSI source files.
These cause the generated docbook to be incorrect.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix docbook problems in rapidio source files.
These cause the generated docbook to be incorrect.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix docbook problems in filesystems.tmpl.
These cause the generated docbook to be incorrect.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86:
  x86: revert "x86: fix pmd_bad and pud_bad to support huge pages"
  x86: revert "x86: CPA: avoid split of alias mappings"

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (24 commits)
  [POWERPC] Convert the cell IOMMU fixed mapping to 16M IOMMU pages
  [POWERPC] Allow for different IOMMU page sizes in cell IOMMU code
  [POWERPC] Cell IOMMU: n_pte_pages is in 4K page units, not IOMMU_PAGE_SIZE
  [POWERPC] Split setup of IOMMU stab and ptab, allocate dynamic/fixed ptabs separately
  [POWERPC] Move allocation of cell IOMMU pad page
  [POWERPC] Remove unused pte_offset variable
  [POWERPC] Use it_offset not pte_offset in cell IOMMU code
  [POWERPC] Clearup cell IOMMU fixed mapping terminology
  [POWERPC] enable hardware watchpoints on cell blades
  [POWERPC] move celleb DABRX definitions
  [POWERPC] OProfile: enable callgraph support for Cell
  [POWERPC] spufs: fix use time accounting on SPE-overcommit
  [POWERPC] spufs: serialize SLB invalidation against SLB loading
  [POWERPC] spufs: invalidate SLB translation before adding a new entry
  [POWERPC] spufs: synchronize IRQ when disabling
  [POWERPC] spufs: fix order of sputrace thread IDs
  [POWERPC] Xilinx: hwicap cleanup
  [POWERPC] 4xx: Use correct board info structure in cuboot wrappers
  [POWERPC] spufs: fix invalid scheduling of forgotten contexts
  [POWERPC] 44x: add missing define TARGET_4xx and TARGET_440GX to cuboot-taishan
  ...

The new code that removed the limitation on the execve string size
(which was historically 32 pages) replaced it with a much softer limit
based on RLIMIT_STACK which is usually much larger than the traditional
limit.  See commit b6a2fea3 ("mm:
variable length argument support") for details.

However, if you have a small stack limit (perhaps because you need lots
of stacks in a threaded environment), the new heuristic of allowing up
to 1/4th of RLIMIT_STACK to be used for argument and environment strings
could actually be smaller than the old limit.

So just say that it's ok to have up to ARG_MAX strings regardless of the
value of RLIMIT_STACK, and check the rlimit only when going over that
traditional limit.

(Of course, if you actually have a *really* small stack limit, the whole
stack itself will be limited before you hit ARG_MAX, but that has always
been true and is clearly the right behaviour anyway).
Acked-by: Carlos O'Donell <carlos@codesourcery.com>
Cc: Michael Kerrisk <michael.kerrisk@googlemail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ollie Wild <aaw@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This reverts commit cded932b.

Arjan bisected down a boot-time hang to this, saying:
  ".. it prevents the kernel to finish booting on my (Penryn based)
   laptop.  The boot stops right after freeing the init memory."

and while it's not clear exactly what triggers it, at this stage we're
better off just reverting it while Ingo tries to figure out what went
wrong.
Requested-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Hans Rosenfeld <hans.rosenfeld@amd.com>
Cc: Nish Aravamudan <nish.aravamudan@gmail.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

revert commit cded932b,
"x86: fix pmd_bad and pud_bad to support huge pages", it causes
a bootup hang, as reported and bisected by Arjan van de Ven.
Bisected-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Revert:

  commit 8be8f54b
  Author: Thomas Gleixner <tglx@linutronix.de>
  Date:   Sat Feb 23 20:43:21 2008 +0100

      x86: CPA: avoid split of alias mappings

because it clearly mishandles the case when __change_page_attr(), called
from __change_page_attr_set_clr(), changes cpa->processed to 1 and
cpa_process_alias(cpa) is executed right after that.

This crashes my x86-64 test box early in the boot process
(ref. http://bugzilla.kernel.org/show_bug.cgi?id=10140#c4).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

The only tricky part is we need to adjust the PTE insertion loop to
cater for holes in the page table. The PTEs for each segment start on
a 4K boundary, so with 16M pages we have 16 PTEs per segment and then
a gap to the next 4K page boundary.

It might be possible to allocate the PTEs for each segment separately,
saving the memory currently filling the gaps. However we'd need to
check that's OK with the hardware, and that it actually saves memory.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Make some preliminary changes to cell_iommu_alloc_ptab() to allow it to
take the page size as a parameter rather than assuming IOMMU_PAGE_SIZE.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

We use n_pte_pages to calculate the stride through the page tables, but
we also use it to set the NPPT value in the segment table entry. That is
defined as the number of 4K pages per segment, so we should calculate
it as such regardless of the IOMMU page size.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Currently the cell IOMMU code allocates the entire IOMMU page table in a
contiguous chunk. This is nice and tidy, but for machines with larger
amounts of RAM the page table allocation can fail due to it simply being
too large.

So split the segment table and page table setup routine, and arrange to
have the dynamic and fixed page tables allocated separately.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

There's no need to allocate the pad page unless we're going to actually
use it - so move the allocation to where we know we're going to use it.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

The cell IOMMU code no longer needs to save the pte_offset variable
separately, it is incorporated into tbl->it_offset.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

The cell IOMMU tce build and free routines use pte_offset to convert
the index passed from the generic IOMMU code into a page table offset.

This takes into account the SPIDER_DMA_OFFSET which sets the top bit
of every DMA address.

However it doesn't cater for the IOMMU window starting at a non-zero
address, as the base of the window is not incorporated into pte_offset
at all.

As it turns out tbl->it_offset already contains the value we need, it
takes into account the base of the window and also pte_offset. So use
it instead!
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

It's called the fixed mapping, not the static mapping.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>