Syscall number 224 was absent from the table, which I believe means that
the SPU can cause an oops by attempting to use it.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NPaul Mackerras <paulus@samba.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

If the skb allocation fails, the current error path calls
dev_kfree_skb_irq() with a NULL argument.  Also, 'err' is not being used.

Coverity CID: 275.
Signed-off-by: NFlorin Malita <fmalita@gmail.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Writing cr0 to cr2 register can't be right.  This fixes the typo.  I wonder
how it could survive so long.
Signed-off-by: NPavel Machek <pavel@suse.cz>
Cc: Zachary Amsden <zach@vmware.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

We still don't have the tty layer licensing compatibility quite right.

tty_insert_flip_char() used to be inlined in include/linux/tty_flip.h.  It
is now out-of-lined and hence needs EXPORT_SYMBOL() to be back-compatible.

One known offender is the Intel Modem driver.

Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Else a subsequent bio_clone might make a mess.
Signed-off-by: NNeil Brown <neilb@suse.de>
Cc: "Don Dupuis" <dondster@gmail.com>
Acked-by: NJens Axboe <axboe@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This loop that sets up the hash_table has problems.

Careful examination will show that the last time through, everything but
the first line is pointless.  This is because all it does is change 'cur'
and 'size' and neither of these are used after the loop.  This should ring
warning bells...  That last time through the loop,

        size += conf->strip_zone[cur].size

can index off the end of the strip_zone array.  Depending on what it finds
there, it might exit the loop cleanly, or it might spin going further and
further beyond the array until it hits an unmapped address.

This patch rearranges the code so that the last, pointless, iteration of
the loop never happens.  i.e.  the one statement of the last loop that is
needed is moved the the end of the previous loop - or to before the loop
starts - and the loop counter starts from 1 instead of 0.

Cc: "Don Dupuis" <dondster@gmail.com>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Both cause the 'entries' count in the export cache to be non-zero at module
removal time, so unregistering that cache fails and results in an oops.

1/ exp_pseudoroot (used for NFSv4 only) leaks a reference to an export
   entry.
2/ sunrpc_cache_update doesn't increment the entries count when it adds
   an entry.

Thanks to "david m.  richter" <richterd@citi.umich.edu> for triggering the
problem and finding one of the bugs.

Cc: "david m. richter" <richterd@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

These flags are needed by userspace - move them outside __KERNEL__

(Pointed out by dwmw2)

Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

FATAL: modpost: GPL-incompatible module sunsu uses the GPL-only symbol tty_insert_flip_string_flags
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit 5ce74abe (and its
dependent commit 8a5bc075), because of
audio underruns.

Reported by Rene Herman <rene.herman@keyaccess.nl>, who also pinpointed
the exact cause of the underruns:

  "Audio underruns galore, with only ogg123 and firefox (browsing the
   GIT tree online is also a nice trigger by the way).

   If I back it out, everything is fine for me again."

Cc: Rene Herman <rene.herman@keyaccess.nl>
Cc: Mike Galbraith <efault@gmx.de>
Acked-by: NCon Kolivas <kernel@kolivas.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

* master.kernel.org:/pub/scm/linux/kernel/git/mchehab/v4l-dvb: (33 commits)
  V4L/DVB (3965): Fix CONFIG_VIDEO_VIVI=y build bug
  V4L/DVB (3964): Bt8xx/bttv-cards.c: fix off-by-one errors
  V4L/DVB (3914): Vivi build fix
  V4L/DVB (3912): Sparc32 vivi fix
  V4L/DVB (3832): Get_dvb_firmware: download nxt2002 firmware from new driver location
  V4L/DVB (3829): Fix frequency values in the ranges structures of the LG TDVS H06xF tuners
  V4L/DVB (3826): Saa7134: Missing 'break' in Terratec Cinergy 400 TV initialization
  V4L/DVB (3825): Remove broken 'fast firmware load' from cx25840.
  V4L/DVB (3819): Cxusb-bluebird: bug-fix: power down corrupts frontend
  V4L/DVB (3813): Add support for TCL M2523_5N_E tuner.
  V4L/DVB (3804): Tweak bandselect setup fox cx24123
  V4L/DVB (3803): Various correctness fixes to tuning.
  V4L/DVB (3797): Always wait for diseqc queue to become ready before transmitting a diseqc message
  V4L/DVB (3796): Add several debug messages to cx24123 code
  V4L/DVB (3795): Fix for CX24123 & low symbol rates
  V4L/DVB (3792): Kbuild: DVB_BT8XX must select DVB_ZL10353
  V4L/DVB (3790): Use after free in drivers/media/video/em28xx/em28xx-video.c
  V4L/DVB (3788): Fix compilation with V4L1_COMPAT
  V4L/DVB (3782): Removed uneeded stuff from pwc Makefile
  V4L/DVB (3775): Add VIVI Kconfig stuff
  ...

WARNING: sound/oss/ad1848.o - Section mismatch: reference to .init.data:ad1848_isapnp_list from .text between 'ad1848_init_generic' (at offset 0x46f0) and 'kmalloc'
WARNING: sound/oss/ad1848.o - Section mismatch: reference to .init.data:ad1848_isapnp_list from .text between 'ad1848_init_generic' (at offset 0x46f8) and 'kmalloc'
WARNING: sound/oss/ad1848.o - Section mismatch: reference to .init.data:ad1848_isapnp_list from .text between 'ad1848_init_generic' (at offset 0x4818) and 'kmalloc'

Also,

sound/oss/ad1848.c: In function `ad1848_init':
sound/oss/ad1848.c:2029: warning: cast to pointer from integer of different size
sound/oss/ad1848.c: In function `ad1848_unload':
sound/oss/ad1848.c:2178: warning: cast to pointer from integer of different size
sound/oss/ad1848.c: In function `adintr':
sound/oss/ad1848.c:2207: warning: cast from pointer to integer of different size
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

WARNING: sound/oss/nm256_audio.o - Section mismatch: reference to .init.text:nm256_peek_for_sig from .text between 'nm256_install' (at offset 0x3ba4) and 'nm256_probe'                                                                         WARNING: sound/oss/nm256_audio.o - Section mismatch: reference to .init.text:nm256_peek_for_sig from .text between 'nm256_install' (at offset 0x3bac) and 'nm256_probe'                                                                         WARNING: sound/oss/nm256_audio.o - Section mismatch: reference to .init.text: from .text between 'nm256_install' (at offset 0x3dcc) and 'nm256_probe'           WARNING: sound/oss/nm256_audio.o - Section mismatch: reference to .init.text: from .text between 'nm256_install' (at offset 0x3dd0) and 'nm256_probe'
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

sound/isa/es18xx.c: In function `snd_es18xx_identify':
sound/isa/es18xx.c:1606: warning: implicit declaration of function `udelay'

Cc: Jaroslav Kysela <perex@suse.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

WARNING: sound/drivers/mpu401/snd-mpu401.o - Section mismatch: reference to .init.text: from .text between 'snd_mpu401_pnp_probe' (at offset 0x1f7) and 'snd_mpu401_pnp_remove'

Cc: Jaroslav Kysela <perex@suse.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

WARNING: drivers/video/i810/i810fb.o - Section mismatch: reference to .init.data: from .text between 'i810_fix_offsets' (at offset 0x1b88) and 'i810_alloc_agp_mem'
WARNING: drivers/video/i810/i810fb.o - Section mismatch: reference to .init.data: from .text between 'i810_fix_offsets' (at offset 0x1b8f) and 'i810_alloc_agp_mem'
WARNING: drivers/video/i810/i810fb.o - Section mismatch: reference to .init.data: from .text between 'i810_fix_offsets' (at offset 0x1ba3) and 'i810_alloc_agp_mem'
WARNING: drivers/video/i810/i810fb.o - Section mismatch: reference to .init.data: from .text between 'i810_fix_offsets' (at offset 0x1bb5) and 'i810_alloc_agp_mem'
WARNING: drivers/video/i810/i810fb.o - Section mismatch: reference to .init.data: from .text between 'i810_fix_offsets' (at offset 0x1bc6) and 'i810_alloc_agp_mem'
WARNING: drivers/video/i810/i810fb.o - Section mismatch: reference to .init.data: from .text between 'i810_init_defaults' (at offset 0x1dd8) and 'i810_init_device'
WARNING: drivers/video/i810/i810fb.o - Section mismatch: reference to .init.data: from .text between 'i810_init_defaults' (at offset 0x1dfb) and 'i810_init_device'

Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

WARNING: drivers/pcmcia/pd6729.o - Section mismatch: reference to .init.text: from .text between 'pd6729_pci_probe' (at offset 0x9a8) and 'pd6729_pci_remove'

Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Andy added code to buddy allocator which does not require the zone's
endpoints to be aligned to MAX_ORDER.  An issue is that the buddy allocator
requires the node_mem_map's endpoints to be MAX_ORDER aligned.  Otherwise
__page_find_buddy could compute a buddy not in node_mem_map for partial
MAX_ORDER regions at zone's endpoints.  page_is_buddy will detect that
these pages at endpoints are not PG_buddy (they were zeroed out by bootmem
allocator and not part of zone).  Of course the negative here is we could
waste a little memory but the positive is eliminating all the old checks
for zone boundary conditions.

SPARSEMEM won't encounter this issue because of MAX_ORDER size constraint
when SPARSEMEM is configured.  ia64 VIRTUAL_MEM_MAP doesn't need the logic
either because the holes and endpoints are handled differently.  This
leaves checking alloc_remap and other arches which privately allocate for
node_mem_map.
Signed-off-by: NBob Picco <bob.picco@hp.com>
Acked-by: NMel Gorman <mel@csn.ul.ie>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

People don't like released kernels yelling at them, no matter how real the
error might be.  So only report it if CONFIG_KOBJECT_DEBUG is enabled.

Sent on request of Andrew Morton.

(akpm: should bring this back post-2.6.17)
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Appropriately use -ENOIOCTLCMD and -ENOTTY when the ioctl is not
implemented by a driver.

(akpm: we're not allowed to return -ENOIOCTLCMD to userspace.  This patch does
the right thing).
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Here is an updated r_info layout fix.  Please apply "check SHT_REL
sections" patch before this.

64bit mips has different r_info layout.  This patch fixes modpost
segfault for 64bit little endian mips kernel.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

I found that modpost can not detect section mismatch on mips and i386.  On
mips64, the modpost (with r_info layout fix) can detect it.  The current
modpst only checks SHT_RELA section but I suppose SHT_REL section should be
checked also.  This patch does not contain r_info layout fix.  I'll post an
updated r_info layout fix on next mail.

Check SHT_REL sections as like as SHT_RELA sections to detect section
mismatch.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The 32 bit unsigned substraction (next - jiffies) in stop_hz_timer can
overflow if jiffies gets advanced between next_timer_interrupt and the read
under the xtime lock.  The cast to a u64 then results in a large value
which causes the cpu to wait too long.  Fix this by casting next and
jiffies independently to u64 before subtracting them.

(Spotted by Zachary Amsden <zach@vmware.com>)
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Under certain timing conditions, a race during boot occurs where timer
ticks are being processed on remote CPUs.  The remote timer ticks can
increment jiffies, and if this happens during a window when a timeout is
very close to expiring but a local tick has not yet been delivered, you can
end up with

1) No softirq pending
2) A local timer wheel which is not synced to jiffies
3) No high resolution timer active
4) A local timer which is supposed to fire before the current jiffies value.

In this circumstance, the comparison in next_timer_interrupt overflows,
because the base of the comparison for high resolution timers is jiffies,
but for the softirq timer wheel, it is relative the the current base of the
wheel (jiffies_base).
Signed-off-by: NZachary Amsden <zach@vmware.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

st: Version 20050830, fixed bufsize 32768, s/g segs 256
st 0:0:6:0: Attached scsi tape st0<4>st0: try direct i/o: yes (alignment 512 B)

Cc: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Problem:

If we put a probe onto a callq instruction and the probe is executed,
kernel panic of Bad RIP value occurs.

Root cause:

If resume_execution() found 0xff at first byte of p->ainsn.insn, it must
check the _second_ byte.  But current resume_execution check _first_ byte
again.

I changed it checks second byte of p->ainsn.insn.

Kprobes on i386 don't have this problem, because the implementation is a
little bit different from x86_64.

Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NSatoshi Oshima <soshima@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

o Kdump second kernel boot fails after a system crash if second kernel
  is UP and acpi=off and if crash occurred on a non-boot cpu.

o Issue here is that MP tables report boot cpu lapic id as 0 but second
  kernel is booting on a different processor and MP table data is stale
  in this context. Hence apic_id_registered() check fails in setup_local_APIC()
  when called from APIC_init_uniprocessor().

o Problem is not seen if ACPI is enabled as in that case
  boot_cpu_physical_apicid is read from the LAPIC.

o Problem is not seen with SMP kernels as well because in this case also
  boot_cpu_physical_apicid is read from LAPIC. (smp_boot_cpus()).

o The problem is fixed by reading boot_cpu_physical_apicid from LAPIC
  if it is a UP kernel and CRASH_DUMP is enabled.
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix some outstanding issues with the pxa2xx_spi driver when running on a
PXA270:

- Wrong timeout calculation in the setup function due to different
  peripheral clock rates in the PXAxxx family.

- Bad handling of SSSR_TFS interrupts in interrupt_transfer function.

- Added locking to interface between the pump_messages workqueue and the
  pump_transfers tasklet.

Much thanks to Juergen Beisert for the extensive testing on the PXA270.
Signed-off-by: NStephen Street <stephen@streetfiresound.com>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Hardware based SPI driver for Samsung S3C24XX SoC systems
Signed-off-by: NBen Dooks <ben-linux@fluff.org>
Cc: David Brownell <david-b@pacbell.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

SPI driver for SPI by GPIO on the Samsung S3C24XX series of SoC processors.
Signed-off-by: NBen Dooks <ben-linux@fluff.org>
Cc: Greg KH <greg@kroah.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

- remove the following global function that is both unused and
  unimplemented:
  - register_firmware()

- make the following needlessly global function static:
  - firmware_class_uevent()
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This driver supports the SPI controller on the MPC83xx SoC devices from
Freescale.  Note, this driver supports only the simple shift register SPI
controller and not the descriptor based CPM or QUICCEngine SPI controller.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Because several developers asked me about referenced but missing
spi_add_master(), I think that this patch should be applied ...  it
corrects comments so they refer to spi_register_master() instead.
Signed-off-by: Ndmitry pervushin <dpervushin@ru.mvista.com>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This fixes coverity bug id #1237.  After the while loop, it is possible for
i == ISDN_LMSNLEN.  If this happens the terminating '\0' is written after
the end of the array.
Signed-off-by: NEric Sesterhenn <snakebyte@gmx.de>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

It's too easy to incorrectly call cpuset_zone_allowed() in an atomic
context without __GFP_HARDWALL set, and when done, it is not noticed until
a tight memory situation forces allocations to be tried outside the current
cpuset.

Add a 'might_sleep_if()' check, to catch this earlier on, instead of
waiting for a similar check in the mutex_lock() code, which is only rarely
invoked.
Signed-off-by: NPaul Jackson <pj@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Update the kernel/cpuset.c:cpuset_zone_allowed() comment.

The rule for when mm/page_alloc.c should call cpuset_zone_allowed()
was intended to be:

  Don't call cpuset_zone_allowed() if you can't sleep, unless you
  pass in the __GFP_HARDWALL flag set in gfp_flag, which disables
  the code that might scan up ancestor cpusets and sleep.

The explanation of this rule in the comment above cpuset_zone_allowed() was
stale, as a result of a restructuring of some __alloc_pages() code in
November 2005.

Rewrite that comment ...
Signed-off-by: NPaul Jackson <pj@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix a couple of infrequently encountered 'sleeping function called from
invalid context' in the cpuset hooks in __alloc_pages.  Could sleep while
interrupts disabled.

The routine cpuset_zone_allowed() is called by code in mm/page_alloc.c
__alloc_pages() to determine if a zone is allowed in the current tasks
cpuset.  This routine can sleep, for certain GFP_KERNEL allocations, if the
zone is on a memory node not allowed in the current cpuset, but might be
allowed in a parent cpuset.

But we can't sleep in __alloc_pages() if in interrupt, nor if called for a
GFP_ATOMIC request (__GFP_WAIT not set in gfp_flags).

The rule was intended to be:
  Don't call cpuset_zone_allowed() if you can't sleep, unless you
  pass in the __GFP_HARDWALL flag set in gfp_flag, which disables
  the code that might scan up ancestor cpusets and sleep.

This rule was being violated in a couple of places, due to a bogus change
made (by myself, pj) to __alloc_pages() as part of the November 2005 effort
to cleanup its logic, and also due to a later fix to constrain which swap
daemons were awoken.

The bogus change can be seen at:
  http://linux.derkeiler.com/Mailing-Lists/Kernel/2005-11/4691.html
  [PATCH 01/05] mm fix __alloc_pages cpuset ALLOC_* flags

This was first noticed on a tight memory system, in code that was disabling
interrupts and doing allocation requests with __GFP_WAIT not set, which
resulted in __might_sleep() writing complaints to the log "Debug: sleeping
function called ...", when the code in cpuset_zone_allowed() tried to take
the callback_sem cpuset semaphore.

We haven't seen a system hang on this 'might_sleep' yet, but we are at
decent risk of seeing it fairly soon, especially since the additional
cpuset_zone_allowed() check was added, conditioning wakeup_kswapd(), in
March 2006.

Special thanks to Dave Chinner, for figuring this out, and a tip of the hat
to Nick Piggin who warned me of this back in Nov 2005, before I was ready
to listen.
Signed-off-by: NPaul Jackson <pj@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>