o If a task changes cgroup, drop reference to the cfqq associated with io
  context and set cfqq pointer stored in ioc to NULL so that upon next request
  arrival we will allocate a  new queue in new group.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

o Do not allow following three operations across groups for isolation.
	- selection of co-operating queues
	- preemtpions across groups
	- request merging across groups.

o Async queues are currently global and not per group. Allow preemption of
  an async queue if a sync queue in other group gets backlogged.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

o Export disk time and sector used by a group to user space through cgroup
  interface.

o Also export a "dequeue" interface to cgroup which keeps track of how many
  a times a group was deleted from service tree. Helps in debugging.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

o Some debugging aids for CFQ.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

o One can choose to change elevator or delete a cgroup. Implement group
  reference counting so that both elevator exit and cgroup deletion can
  take place gracefully.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Nauman Rafique <nauman@google.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

o Determine the cgroup IO submitting task belongs to and create the cfq
  group if it does not exist already.

o Also link cfqq and associated cfq group.

o Currently all async IO is mapped to root group.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

o This patch introduces the functionality to do the accounting of group time
  when a queue expires. This time used decides which is the group to go
  next.

o Also introduce the functionlity to save and restore the workload type
  context with-in group. It might happen that once we expire the cfq queue
  and group, a different group will schedule in and we will lose the context
  of the workload type. Hence save and restore it upon queue expiry.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

o So far we had 300ms soft target latency system wide. Now with the
  introduction of cfq groups, divide that latency by number of groups so
  that one can come up with group target latency which will be helpful
  in determining the workload slice with-in group and also the dynamic
  slice length of the cfq queue.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

o Bring in the per cfq group weight and how vdisktime is calculated for the
  group. Also bring in the functionality of updating the min_vdisktime of
  the group service tree.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

o This is basic implementation of blkio controller cgroup interface. This is
  the common interface visible to user space and should be used by different
  IO control policies as we implement those.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

o So far we just had one cfq_group in cfq_data. To create space for more than
  one cfq_group, we need to have a service tree of groups where all the groups
  can be queued if they have active cfq queues backlogged in these.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

o Currently cfqq deletes a queue from service tree if it is empty (even if
  we might idle on the queue). This patch keeps the queue on service tree
  hence associated group remains on the service tree until we decide that
  we are not going to idle on the queue and expire it.

o This just helps in time accounting for queue/group and in implementation
  of rest of the patches.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

o Implement a macro to traverse each service tree in the group. This avoids
  usage of double for loop and special condition for idle tree 4 times.

o Macro is little twisted because of special handling of idle class service
  tree.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

o This patch introduce the notion of cfq groups. Soon we will can have multiple
  groups of different weights in the system.

o Various service trees (prioclass and workload type trees), will become per
  cfq group. So hierarchy looks as follows.

			cfq_groups
			   |
			workload type
			   |
		        cfq queue

o When an scheduling decision has to be taken, first we select the cfq group
  then workload with-in the group and then cfq queue with-in the workload
  type.

o This patch just makes various workload service tree per cfq group and
  introduce the function to be able to choose a group for scheduling.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

o must_dispatch flag should be set only if we decided not to run the queue
  and dispatch the request.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

- no one is calling wb_writeback and write_cache_pages with
  wbc.nonblocking=1 any more
- lumpy pageout will want to do nonblocking writeback without the
  congestion wait

So remove the congestion checks as suggested by Chris.
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Alex Elder <aelder@sgi.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

It will lower the flush priority for NFS, and maybe more in future.
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

This is dead code because no bdi flush thread will be started for
!bdi_cap_writeback_dirty bdi.
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

To touch task->flags directly is racy. thaw_process() still has race
(changing non_current->flags, but this is another issue) though, I think
it's much better off.

So, use thaw_process() instead.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Since commit 2f5cb738, each queue can send
up to 4 * 4 requests if only one queue exists. I wonder why we have such limit.
Device supports tag can send more requests. For example, AHCI can send 31
requests. Test (direct aio randread) shows the limits reduce about 4% disk
thoughput.
On the other hand, since we send one request one time, if other queue
pop when current is sending more than cfq_quantum requests, current queue will
stop send requests soon after one request, so sounds there is no big latency.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

The discard ioctl is used by mkfs utilities to clear a block device
prior to putting metadata down.  However, not all devices return zeroed
blocks after a discard.  Some drives return stale data, potentially
containing old superblocks.  It is therefore important to know whether
discarded blocks are properly zeroed.

Both ATA and SCSI drives have configuration bits that indicate whether
zeroes are returned after a discard operation.  Implement a block level
interface that allows this information to be bubbled up the stack and
queried via a new block device ioctl.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

request_region should be used with release_region, not request_mem_region.

Geert Uytterhoeven pointed out that in the case of drivers/video/gbefb.c,
the problem is actually the other way around; request_mem_region should be
used instead of request_region.

The semantic patch that finds/fixes this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r1@
expression start;
@@

request_region(start,...)

@b1@
expression r1.start;
@@

request_mem_region(start,...)

@depends on !b1@
expression r1.start;
expression E;
@@

- release_mem_region
+ release_region
  (start,E)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

TXx9 SPI bit rate is calculated by:
        fBR = (spi-baseclk) / (n + 1)
Fix calculation of min_speed_hz, max_speed_hz and n.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sameo/mfd-2.6:
  mfd: Correct WM831X_MAX_ISEL_VALUE

These laptops often leave i8042 in a wierd state resulting in non-
operational touchpad and keyboard.
Signed-off-by: Anisse Astier <anisse@astier.eu>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://neil.brown.name/md:
  md: revert incorrect fix for read error handling in raid1.

Jon confirms that recent modprobe will look in /proc/cmdline, so these
cmdline options can still be used.

See http://bugzilla.kernel.org/show_bug.cgi?id=14164Reported-by: Adam Williamson <awilliam@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
  MIPS: RB532: Fix devices.c compilation.
  MIPS: Fix MIPS I build.

* git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog:
  [PATCH] rc32434_wdt: fix compilation failure
  [WATCHDOG] rc32434_wdt.c: use resource_size()

On the parisc architecture we face for each and every loaded kernel module
this kernel "badness warning":
  sysfs: cannot create duplicate filename '/module/ac97_bus/sections/.text'
  Badness at fs/sysfs/dir.c:487

Reason for that is, that on parisc all kernel modules do have multiple
.text sections due to the usage of the -ffunction-sections compiler flag
which is needed to reach all jump targets on this platform.

An objdump on such a kernel module gives:
Sections:
Idx Name          Size      VMA       LMA       File off  Algn
  0 .note.gnu.build-id 00000024  00000000  00000000  00000034  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  1 .text         00000000  00000000  00000000  00000058  2**0
                  CONTENTS, ALLOC, LOAD, READONLY, CODE
  2 .text.ac97_bus_match 0000001c  00000000  00000000  00000058  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, CODE
  3 .text         00000000  00000000  00000000  000000d4  2**0
                  CONTENTS, ALLOC, LOAD, READONLY, CODE
...
Since the .text sections are empty (size of 0 bytes) and won't be
loaded by the kernel module loader anyway, I don't see a reason
why such sections need to be listed under
/sys/module/<module_name>/sections/<section_name> either.

The attached patch does solve this issue by not exporting section
names which are empty.

This fixes bugzilla http://bugzilla.kernel.org/show_bug.cgi?id=14703Signed-off-by: Helge Deller <deller@gmx.de>
CC: rusty@rustcorp.com.au
CC: akpm@linux-foundation.org
CC: James.Bottomley@HansenPartnership.com
CC: roland@redhat.com
CC: dave@hiauly1.hia.nrc.ca
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lrg/voltage-2.6:
  regulator: Initialise wm831x structure pointor for ISINK driver

The version that made it into mainline missed the initialisation of the
chip handle.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

We should now use dev_set_drvdata to set the driver driver_data field.
Signed-off-by: Florian Fainelli <florian@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/747/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Broken by d63c63e889bbeeaa461a8addf1245f89f3ce4ece (lmo) rsp.
f1e39a4a (kernel.org).
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Patchwork: http://patchwork.linux-mips.org/patch/746/

* 'fix' of git://git.kernel.org/pub/scm/linux/kernel/git/ycmiao/pxa-linux-2.6:
  [ARM] pxamci: call mmc_remove_host() before freeing resources

mmc_remove_host() will cause the mmc core to switch off the bus power by
eventually calling pxamci_set_ios(). This function uses the regulator or
the GPIO which have been freed already.

This causes the following Oops on module unload.

[   49.519649] Unable to handle kernel paging request at virtual address 30303a70
[   49.526878] pgd = c7084000
[   49.529563] [30303a70] *pgd=00000000
[   49.533136] Internal error: Oops: 5 [#1]
[   49.537025] last sysfs file: /sys/devices/platform/pxa27x-ohci/usb1/1-1/1-1:1.0/host0/target0:0:0/0:0:0:0/scsi_level
[   49.547471] Modules linked in: pxamci(-) eeti_ts
[   49.552061] CPU: 0    Not tainted  (2.6.32-rc8 #322)
[   49.557001] PC is at regulator_is_enabled+0x3c/0xbc
[   49.561846] LR is at regulator_is_enabled+0x30/0xbc
[   49.566691] pc : [<c01a2448>]    lr : [<c01a243c>]    psr: 60000013
[   49.566702] sp : c7083e70  ip : 30303a30  fp : 00000000
[   49.578093] r10: c705e200  r9 : c7082000  r8 : c705e2e0
[   49.583280] r7 : c7061340  r6 : c7061340  r5 : c7083e70  r4 : 00000000
[   49.589759] r3 : c04dc434  r2 : c04dc434  r1 : c03eecea  r0 : 00000047
[   49.596241] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
[   49.603329] Control: 0000397f  Table: a7084018  DAC: 00000015
[   49.609031] Process rmmod (pid: 1101, stack limit = 0xc7082278)
[   49.614908] Stack: (0xc7083e70 to 0xc7084000)
[   49.619238] 3e60:                                     c7082000 c703c4f8 c705ea00 c04f4074
[   49.627366] 3e80: 00000000 c705e3a0 ffffffff c0247ddc c70361a0 00000000 c705e3a0 ffffffff
[   49.635499] 3ea0: c705e200 bf006400 c78c4f00 c705e200 c705e3a0 ffffffff c705e200 ffffffff
[   49.643633] 3ec0: c04d8ac8 c02476d0 ffffffff c0247c60 c705e200 c0248678 c705e200 c0249064
[   49.651765] 3ee0: ffffffff bf006204 c04d8ad0 c04d8ad0 c04d8ac8 bf007490 00000880 c00440c4
[   49.659898] 3f00: 0000b748 c01c5708 bf007490 c01c44c8 c04d8ac8 c04d8afc bf007490 c01c4570
[   49.668031] 3f20: bf007490 bf00750c c04f4258 c01c37a4 00000000 bf00750c c7083f44 c007b014
[   49.676162] 3f40: 4000d000 6d617870 08006963 00000001 00000000 c7085000 00000001 00000000
[   49.684287] 3f60: 4000d000 c7083f8c 00000001 bea01a54 00005401 c7ab1400 c00440c4 00082000
[   49.692420] 3f80: bf00750c 00000880 c7083f8c 00000000 4000cfa8 00000000 00000880 bea01cc8
[   49.700552] 3fa0: 00000081 c0043f40 00000000 00000880 bea01cc8 00000880 00000006 00000000
[   49.708677] 3fc0: 00000000 00000880 bea01cc8 00000081 00000097 0000cca4 0000b748 00000000
[   49.716802] 3fe0: 4001a4f0 bea01cc0 00018bf4 4001a4fc 20000010 bea01cc8 a063e021 a063e421
[   49.724958] [<c01a2448>] (regulator_is_enabled+0x3c/0xbc) from [<c0247ddc>] (mmc_regulator_set_ocr+0x14/0xd8)
[   49.734836] [<c0247ddc>] (mmc_regulator_set_ocr+0x14/0xd8) from [<bf006400>] (pxamci_set_ios+0xd8/0x17c [pxamci])
[   49.745044] [<bf006400>] (pxamci_set_ios+0xd8/0x17c [pxamci]) from [<c02476d0>] (mmc_power_off+0x50/0x58)
[   49.754555] [<c02476d0>] (mmc_power_off+0x50/0x58) from [<c0247c60>] (mmc_detach_bus+0x68/0xc4)
[   49.763207] [<c0247c60>] (mmc_detach_bus+0x68/0xc4) from [<c0248678>] (mmc_stop_host+0xd4/0x1bc)
[   49.771944] [<c0248678>] (mmc_stop_host+0xd4/0x1bc) from [<c0249064>] (mmc_remove_host+0xc/0x20)
[   49.780681] [<c0249064>] (mmc_remove_host+0xc/0x20) from [<bf006204>] (pxamci_remove+0xc8/0x174 [pxamci])
[   49.790211] [<bf006204>] (pxamci_remove+0xc8/0x174 [pxamci]) from [<c01c5708>] (platform_drv_remove+0x1c/0x24)
[   49.800164] [<c01c5708>] (platform_drv_remove+0x1c/0x24) from [<c01c44c8>] (__device_release_driver+0x7c/0xc4)
[   49.810110] [<c01c44c8>] (__device_release_driver+0x7c/0xc4) from [<c01c4570>] (driver_detach+0x60/0x8c)
[   49.819535] [<c01c4570>] (driver_detach+0x60/0x8c) from [<c01c37a4>] (bus_remove_driver+0x90/0xcc)
[   49.828452] [<c01c37a4>] (bus_remove_driver+0x90/0xcc) from [<c007b014>] (sys_delete_module+0x1d8/0x254)
[   49.837891] [<c007b014>] (sys_delete_module+0x1d8/0x254) from [<c0043f40>] (ret_fast_syscall+0x0/0x28)
[   49.847145] Code: eb06c53a e596c030 e1a0500d e59f106c (e59c0040)
[   49.853566] ---[ end trace b5fa66a00cea142f ]---
Signed-off-by: Daniel Mack <daniel@caiaq.de>
Reported-by: Sven Neumann <s.neumann@raumfeld.com>
Cc: Pierre Ossman <pierre@ossman.eu>
Cc: linux-mmc@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: stable@kernel.org
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>

This patch fixes the compilation failure of
rc32434 due to a bad module parameter description.
Signed-off-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>