Using perf to trace L1 dcache misses and dumping data addresses I found a few
variables taking a lot of misses. Since they are almost never written, they
should go into the __read_mostly section.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The cputime code has a few places that do per_cpu(, smp_processor_id()).
Replace them with __get_cpu_var().
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NRobert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Use #define pr_fmt(fmt) "viod: " fmt
Remove #define VIOD_KERN_WARNING and VIOD_KERN_INFO
Convert printk(VIOD_KERN_<level> to pr_<level>
Coalesce long format strings
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NStephen Rothwell <sfr@canb.auug.org.au>

 drivers/block/viodasd.c |   86 +++++++++++++++++++---------------------------
 1 files changed, 36 insertions(+), 50 deletions(-)
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  cfq-iosched: Do not idle on async queues
  blk-cgroup: Fix potential deadlock in blk-cgroup
  block: fix bugs in bio-integrity mempool usage
  block: fix bio_add_page for non trivial merge_bvec_fn case
  drbd: null dereference bug
  drbd: fix max_segment_size initialization

Improve handling of fragmented per-CPU vmaps.  We previously don't free
up per-CPU maps until all its addresses have been used and freed.  So
fragmented blocks could fill up vmalloc space even if they actually had
no active vmap regions within them.

Add some logic to allow all CPUs to have these blocks purged in the case
of failure to allocate a new vm area, and also put some logic to trim
such blocks of a current CPU if we hit them in the allocation path (so
as to avoid a large build up of them).

Christoph reported some vmap allocation failures when using the per CPU
vmap APIs in XFS, which cannot be reproduced after this patch and the
previous bug fix.

Cc: linux-mm@kvack.org
Cc: stable@kernel.org
Tested-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NNick Piggin <npiggin@suse.de>
--
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

RCU list walking of the per-cpu vmap cache was broken.  It did not use
RCU primitives, and also the union of free_list and rcu_head is
obviously wrong (because free_list is indeed the list we are RCU
walking).

While we are there, remove a couple of unused fields from an earlier
iteration.

These APIs aren't actually used anywhere, because of problems with the
XFS conversion.  Christoph has now verified that the problems are solved
with these patches.  Also it is an exported interface, so I think it
will be good to be merged now (and Christoph wants to get the XFS
changes into their local tree).

Cc: stable@kernel.org
Cc: linux-mm@kvack.org
Tested-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NNick Piggin <npiggin@suse.de>
--
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  random: Remove unused inode variable
  crypto: padlock-sha - Add import/export support
  random: drop weird m_time/a_time manipulation

* git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-fixes:
  GFS2: Use GFP_NOFS for alloc structure
  GFS2: Fix previous patch
  GFS2: Don't withdraw on partial rindex entries
  GFS2: Fix refcnt leak on gfs2_follow_link() error path

* 'sh/for-2.6.33' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
  sh: Fix access to released memory in clk_debugfs_register_one()
  sh: Fix access to released memory in dwarf_unwinder_cleanup()
  usb: r8a66597-hdc disable interrupts fix
  spi: spi_sh_msiof: Fixed data sampling on the correct edge

* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
  MIPS: 64-bit: Detect virtual memory size
  MIPS: AR7: Fix USB slave mem range typo
  MIPS: Alchemy: Fix dbdma ring destruction memory debugcheck.

Commit 221af7f8 ("Split 'flush_old_exec' into two functions") split
the function at the point of no return - ie right where there were no
more error cases to check.  That made sense from a technical standpoint,
but when we then also combined it with the actual personality setting
going in between flush_old_exec() and setup_new_exec(), it needs to be a
bit more careful.

In particular, we need to make sure that we really flush the old
personality bits in the 'flush' stage, rather than later in the 'setup'
stage, since otherwise we might be flushing the _new_ personality state
that we're just setting up.

So this moves the flags and personality flushing (and 'flush_thread()',
which is the arch-specific function that generally resets lazy FP state
etc) of the old process into flush_old_exec(), so that it doesn't affect
any state that execve() is setting up for the new process environment.

This was reported by Michal Simek as breaking his Microblaze qemu
environment.
Reported-and-tested-by: NMichal Simek <michal.simek@petalogix.com>
Cc: Peter Anvin <hpa@zytor.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Few weeks back, Shaohua Li had posted similar patch. I am reposting it
with more test results.

This patch does two things.

- Do not idle on async queues.

- It also changes the write queue depth CFQ drives (cfq_may_dispatch()).
  Currently, we seem to driving queue depth of 1 always for WRITES. This is
  true even if there is only one write queue in the system and all the logic
  of infinite queue depth in case of single busy queue as well as slowly
  increasing queue depth based on last delayed sync request does not seem to
  be kicking in at all.

This patch will allow deeper WRITE queue depths (subjected to the other
WRITE queue depth contstraints like cfq_quantum and last delayed sync
request).

Shaohua Li had reported getting more out of his SSD. For me, I have got
one Lun exported from an HP EVA and when pure buffered writes are on, I
can get more out of the system. Following are test results of pure
buffered writes (with end_fsync=1) with vanilla and patched kernel. These
results are average of 3 sets of run with increasing number of threads.

AVERAGE[bufwfs][vanilla]
-------
job       Set NR  ReadBW(KB/s)   MaxClat(us)    WriteBW(KB/s)  MaxClat(us)
---       --- --  ------------   -----------    -------------  -----------
bufwfs    3   1   0              0              95349          474141
bufwfs    3   2   0              0              100282         806926
bufwfs    3   4   0              0              109989         2.7301e+06
bufwfs    3   8   0              0              116642         3762231
bufwfs    3   16  0              0              118230         6902970

AVERAGE[bufwfs] [patched kernel]
-------
bufwfs    3   1   0              0              270722         404352
bufwfs    3   2   0              0              206770         1.06552e+06
bufwfs    3   4   0              0              195277         1.62283e+06
bufwfs    3   8   0              0              260960         2.62979e+06
bufwfs    3   16  0              0              299260         1.70731e+06

I also ran buffered writes along with some sequential reads and some
buffered reads going on in the system on a SATA disk because the potential
risk could be that we should not be driving queue depth higher in presence
of sync IO going to keep the max clat low.

With some random and sequential reads going on in the system on one SATA
disk I did not see any significant increase in max clat. So it looks like
other WRITE queue depth control logic is doing its job. Here are the
results.

AVERAGE[brr, bsr, bufw together] [vanilla]
-------
job       Set NR  ReadBW(KB/s)   MaxClat(us)    WriteBW(KB/s)  MaxClat(us)
---       --- --  ------------   -----------    -------------  -----------
brr       3   1   850            546345         0              0
bsr       3   1   14650          729543         0              0
bufw      3   1   0              0              23908          8274517

brr       3   2   981.333        579395         0              0
bsr       3   2   14149.7        1175689        0              0
bufw      3   2   0              0              21921          1.28108e+07

brr       3   4   898.333        1.75527e+06    0              0
bsr       3   4   12230.7        1.40072e+06    0              0
bufw      3   4   0              0              19722.3        2.4901e+07

brr       3   8   900            3160594        0              0
bsr       3   8   9282.33        1.91314e+06    0              0
bufw      3   8   0              0              18789.3        23890622

AVERAGE[brr, bsr, bufw mixed] [patched kernel]
-------
job       Set NR  ReadBW(KB/s)   MaxClat(us)    WriteBW(KB/s)  MaxClat(us)
---       --- --  ------------   -----------    -------------  -----------
brr       3   1   837            417973         0              0
bsr       3   1   14357.7        591275         0              0
bufw      3   1   0              0              24869.7        8910662

brr       3   2   1038.33        543434         0              0
bsr       3   2   13351.3        1205858        0              0
bufw      3   2   0              0              18626.3        13280370

brr       3   4   913            1.86861e+06    0              0
bsr       3   4   12652.3        1430974        0              0
bufw      3   4   0              0              15343.3        2.81305e+07

brr       3   8   890            2.92695e+06    0              0
bsr       3   8   9635.33        1.90244e+06    0              0
bufw      3   8   0              0              17200.3        24424392

So looks like it might make sense to include this patch.

Thanks
Vivek
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Linux kernel 2.6.32 and later allocate address space from the top of the
kernel virtual memory address space.

This patch implements virtual memory size detection for 64 bit MIPS CPUs
to avoid resulting crashes.
Signed-off-by: NGuenter Roeck <guenter.roeck@ericsson.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/935/Reviewed-by: NDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NMarek Skuczynski <mareksk7@gmail.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Signed-off-by: NMarek Skuczynski <mareksk7@gmail.com>
Acked-by: NMatt Fleming <matt@console-pimps.org>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This patch improves disable_controller() in the r8a66597-hdc
driver to disable all interrupts and clear status flags. It
also makes sure that disable_controller() is called during
probe(). This fixes the relatively rare case of unexpected
pending interrupts after kexec reboot.
Signed-off-by: NMagnus Damm <damm@opensource.se>
Acked-by: NYoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

The spi_sh_msiof.c driver presently misconfigures REDG and TEDG. TEDG==0
outputs data at the **rising edge** of the clock and REDG==0 samples data
at the **falling edge** of the clock. Therefore for SPI, TEDG must be
equal to REDG, otherwise the last byte received is not sampled in SPI
mode 3.

This brings the driver in line with the SH7723 HW Reference Manual
settings documented in Figures 20.20 and 20.21 ("SPI Clock and data
timing").
Signed-off-by: NMarkus Pietrek <Markus.Pietrek@emtrion.de>
Acked-by: NMagnus Damm <damm@opensource.se>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

The previous changeset left behind an unused inode variable.
This patch removes it.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

As the padlock driver for SHA uses a software fallback to perform
partial hashing, it must implement custom import/export functions.
Otherwise hmac which depends on import/export for prehashing will
not work with padlock-sha.
Reported-by: NWolfgang Walter <wolfgang.walter@stwm.de>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

No other driver does anything remotely like this that I know of except
for the tty drivers, and I can't see any reason for random/urandom to do
it. In fact, it's a (trivial, harmless) timing information leak. And
obviously, it generates power- and flash-cycle wasting I/O, especially
if combined with something like hwrngd. Also, it breaks ubifs's
expectations.
Signed-off-by: NMatt Mackall <mpm@selenic.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: NAlexander Clouter <alex@digriz.org.uk>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/919/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

DBDMA descriptors need to be located at 32-byte aligned addresses;
however kmalloc in conjunction with the SLAB allocator and
CONFIG_DEBUG_SLUB enabled doesn't deliver any.  The dbdma code works
around that by allocating a larger area and realigning the start
address within it.

When freeing a channel however this adjustment is not taken into
account which results in an oops:

Kernel bug detected[#1]:
[...]
Call Trace:
[<80186010>] cache_free_debugcheck+0x284/0x318
[<801869d8>] kfree+0xe8/0x2a0
[<8010b31c>] au1xxx_dbdma_chan_free+0x2c/0x7c
[<80388dc8>] au1x_pcm_dbdma_free+0x34/0x4c
[<80388fa8>] au1xpsc_pcm_close+0x28/0x38
[<80383cb8>] soc_codec_close+0x14c/0x1cc
[<8036dbb4>] snd_pcm_release_substream+0x60/0xac
[<8036dc40>] snd_pcm_release+0x40/0xa0
[<8018c7a8>] __fput+0x11c/0x228
[<80188f60>] filp_close+0x7c/0x98
[<80189018>] sys_close+0x9c/0xe4
[<801022a0>] stack_done+0x20/0x3c

Fix this by recording the address delivered by kmalloc() and using
it as parameter to kfree().

This fix is only necessary with the SLAB allocator and CONFIG_DEBUG_SLAB
enabled;  non-debug SLAB, SLUB do return nicely aligned addresses,
debug-enabled SLUB currently panics early in the boot process.
Signed-off-by: NManuel Lauss <manuel.lauss@gmail.com>
To: Linux-MIPS <linux-mips@linux-mips.org>
Cc: Manuel Lauss <manuel.lauss@gmail.com>
Patchwork: http://patchwork.linux-mips.org/patch/878/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ASoC: AM3517: ASoC driver not getting compiled
  ASoC: AIC23: Fixing writes to non-existing registers in resume function
  ALSA: hda - Add an ASUS mobo to MSI blacklist

* 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6:
  drm/radeon/kms: Fix oops after radeon_cs_parser_init() failure.
  drm/radeon/kms: move radeon KMS on/off switch out of staging.
  drm/radeon/kms: Bailout of blit if error happen & protect with mutex V3
  drm/vmwgfx: Don't send bad flags to the host
  drm/vmwgfx: Request SVGA version 2 and bail if not found
  drm/vmwgfx: Correctly detect 3D
  drm/ttm: remove unnecessary save_flags and ttm_flag_masked in ttm_bo_util.c
  drm/kms: Remove incorrect comment in struct drm_mode_modeinfo
  drm/ttm: remove padding from ttm_ref_object on 64bit builds
  drm/radeon/kms: release agp on error.
  drm/kms/radeon/agp: Move the check of the aper_size after drm_acp_acquire and drm_agp_info
  drm/kms/radeon/agp: Fix warning, format ‘%d’ expects type ‘int’, but argument 4 has type ‘size_t’
  drm/ttm: Avoid conflicting reserve_memtype during ttm_tt_set_page_caching.
  drm/kms/radeon: pick digitial encoders smarter. (v3)
  drm/radeon/kms: use active device to pick connector for encoder
  drm/radeon/kms: fix incorrect logic in DP vs eDP connector checking.

Merge branch 'reiserfs/kill-bkl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing

* 'reiserfs/kill-bkl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing:
  reiserfs: Fix vmalloc call under reiserfs lock

Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  lockdep: Fix check_usage_backwards() error message

Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf, hw_breakpoint, kgdb: Do not take mutex for kernel debugger
  x86, hw_breakpoints, kgdb: Fix kgdb to use hw_breakpoint API
  hw_breakpoints: Release the bp slot if arch_validate_hwbkpt_settings() fails.
  perf: Ignore perf.data.old
  perf report: Fix segmentation fault when running with '-g none'

Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: Correct printk whitespace in warning from cpu down task check
  sched: Fix incorrect sanity check
  sched: Fix fork vs hotplug vs cpuset namespaces

Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  clocksource: Prevent potential kgdb dead lock

Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  tracing/documentation: Cover new frame pointer semantics
  tracing/documentation: Fix a typo in ftrace.txt
  ring-buffer: Check for end of page in iterator
  ring-buffer: Check if ring buffer iterator has stale data
  tracing: Prevent kernel oops with corrupted buffer

Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86/agp: Fix agp_amd64_init regression
  x86: Add quirk for Intel DG45FC board to avoid low memory corruption
  x86: Add Dell OptiPlex 760 reboot quirk
  x86, UV: Fix RTC latency bug by reading replicated cachelines
  oprofile/x86: add Xeon 7500 series support
  oprofile/x86: fix crash when profiling more than 28 events
  lib/dma-debug.c: mark file-local struct symbol static.
  x86/amd-iommu: Fix deassignment of a device from the pt_domain
  x86/amd-iommu: Fix IOMMU-API initialization for iommu=pt
  x86/amd-iommu: Fix NULL pointer dereference in __detach_device()
  x86/amd-iommu: Fix possible integer overflow

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lrg/voltage-2.6:
  regulator: Specify REGULATOR_CHANGE_STATUS for WM835x LED constraints

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc: TIF_ABI_PENDING bit removal
  powerpc/pseries: Fix xics build without CONFIG_SMP
  powerpc/4xx: Add pcix type 1 transactions
  powerpc/pci: Add missing call to header fixup
  powerpc/pci: Add missing hookup to pci_slot
  powerpc/pci: Add calls to set_pcie_port_type() and set_pcie_hotplug_bridge()
  powerpc/40x: Update the PowerPC 40x board defconfigs
  powerpc/44x: Update PowerPC 44x board defconfigs

The WM8350 LED driver needs to be able to enable and disable the
regulators it is using. Previously the core wasn't properly enforcing
status change constraints so the driver was able to function but this
has always been intended to be required.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@kernel.org
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

This is called under a glock, so its a good plan to use GFP_NOFS
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

The do_div() call needs to remain.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

ince gfs2 writes the rindex file a block at a time, and releases the
exclusive lock after each block, it is possible that another process
will grab the lock in the middle of the write.  Since rindex entries are
not an even divisor of blocks, that other process may see partial
entries.  On grows, this is fine.  The process can simply ignore the the
partial entires. Previously, the code withdrew when it saw partial
entries. Now it simply ignores them.
Signed-off-by: NBenjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

I triggered a lockdep warning as following.

=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.33-rc2 #1
-------------------------------------------------------
test_io_control/7357 is trying to acquire lock:
 (blkio_list_lock){+.+...}, at: [<c053a990>] blkiocg_weight_write+0x82/0x9e

but task is already holding lock:
 (&(&blkcg->lock)->rlock){......}, at: [<c053a949>] blkiocg_weight_write+0x3b/0x9e

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (&(&blkcg->lock)->rlock){......}:
       [<c04583b7>] validate_chain+0x8bc/0xb9c
       [<c0458dba>] __lock_acquire+0x723/0x789
       [<c0458eb0>] lock_acquire+0x90/0xa7
       [<c0692b0a>] _raw_spin_lock_irqsave+0x27/0x5a
       [<c053a4e1>] blkiocg_add_blkio_group+0x1a/0x6d
       [<c053cac7>] cfq_get_queue+0x225/0x3de
       [<c053eec2>] cfq_set_request+0x217/0x42d
       [<c052c8a6>] elv_set_request+0x17/0x26
       [<c0532a0f>] get_request+0x203/0x2c5
       [<c0532ae9>] get_request_wait+0x18/0x10e
       [<c0533470>] __make_request+0x2ba/0x375
       [<c0531985>] generic_make_request+0x28d/0x30f
       [<c0532da7>] submit_bio+0x8a/0x8f
       [<c04d827a>] submit_bh+0xf0/0x10f
       [<c04d91d2>] ll_rw_block+0xc0/0xf9
       [<f86e9705>] ext3_find_entry+0x319/0x544 [ext3]
       [<f86eae58>] ext3_lookup+0x2c/0xb9 [ext3]
       [<c04c3e1b>] do_lookup+0xd3/0x172
       [<c04c56c8>] link_path_walk+0x5fb/0x95c
       [<c04c5a65>] path_walk+0x3c/0x81
       [<c04c5b63>] do_path_lookup+0x21/0x8a
       [<c04c66cc>] do_filp_open+0xf0/0x978
       [<c04c0c7e>] open_exec+0x1b/0xb7
       [<c04c1436>] do_execve+0xbb/0x266
       [<c04081a9>] sys_execve+0x24/0x4a
       [<c04028a2>] ptregs_execve+0x12/0x18

-> #1 (&(&q->__queue_lock)->rlock){..-.-.}:
       [<c04583b7>] validate_chain+0x8bc/0xb9c
       [<c0458dba>] __lock_acquire+0x723/0x789
       [<c0458eb0>] lock_acquire+0x90/0xa7
       [<c0692b0a>] _raw_spin_lock_irqsave+0x27/0x5a
       [<c053dd2a>] cfq_unlink_blkio_group+0x17/0x41
       [<c053a6eb>] blkiocg_destroy+0x72/0xc7
       [<c0467df0>] cgroup_diput+0x4a/0xb2
       [<c04ca473>] dentry_iput+0x93/0xb7
       [<c04ca4b3>] d_kill+0x1c/0x36
       [<c04cb5c5>] dput+0xf5/0xfe
       [<c04c6084>] do_rmdir+0x95/0xbe
       [<c04c60ec>] sys_rmdir+0x10/0x12
       [<c04027cc>] sysenter_do_call+0x12/0x32

-> #0 (blkio_list_lock){+.+...}:
       [<c0458117>] validate_chain+0x61c/0xb9c
       [<c0458dba>] __lock_acquire+0x723/0x789
       [<c0458eb0>] lock_acquire+0x90/0xa7
       [<c06929fd>] _raw_spin_lock+0x1e/0x4e
       [<c053a990>] blkiocg_weight_write+0x82/0x9e
       [<c0467f1e>] cgroup_file_write+0xc6/0x1c0
       [<c04bd2f3>] vfs_write+0x8c/0x116
       [<c04bd7c6>] sys_write+0x3b/0x60
       [<c04027cc>] sysenter_do_call+0x12/0x32

other info that might help us debug this:

1 lock held by test_io_control/7357:
 #0:  (&(&blkcg->lock)->rlock){......}, at: [<c053a949>] blkiocg_weight_write+0x3b/0x9e
stack backtrace:
Pid: 7357, comm: test_io_control Not tainted 2.6.33-rc2 #1
Call Trace:
 [<c045754f>] print_circular_bug+0x91/0x9d
 [<c0458117>] validate_chain+0x61c/0xb9c
 [<c0458dba>] __lock_acquire+0x723/0x789
 [<c0458eb0>] lock_acquire+0x90/0xa7
 [<c053a990>] ? blkiocg_weight_write+0x82/0x9e
 [<c06929fd>] _raw_spin_lock+0x1e/0x4e
 [<c053a990>] ? blkiocg_weight_write+0x82/0x9e
 [<c053a990>] blkiocg_weight_write+0x82/0x9e
 [<c0467f1e>] cgroup_file_write+0xc6/0x1c0
 [<c0454df5>] ? trace_hardirqs_off+0xb/0xd
 [<c044d93a>] ? cpu_clock+0x2e/0x44
 [<c050e6ec>] ? security_file_permission+0xf/0x11
 [<c04bcdda>] ? rw_verify_area+0x8a/0xad
 [<c0467e58>] ? cgroup_file_write+0x0/0x1c0
 [<c04bd2f3>] vfs_write+0x8c/0x116
 [<c04bd7c6>] sys_write+0x3b/0x60
 [<c04027cc>] sysenter_do_call+0x12/0x32

To prevent deadlock, we should take locks as following sequence:

blkio_list_lock -> queue_lock ->  blkcg_lock.

The following patch should fix this bug.
Signed-off-by: NGui Jianfeng <guijianfeng@cn.fujitsu.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Here are the powerpc bits to remove TIF_ABI_PENDING now that
set_personality() is called at the appropriate place in exec.
Signed-off-by: NAndreas Schwab <schwab@linux-m68k.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>