9 years agoblock: add function call to switch the IO scheduler from a driver
Jens Axboe [Mon, 23 Aug 2010 11:52:19 +0000]
block: add function call to switch the IO scheduler from a driver

Currently drivers must do an elevator_exit() + elevator_init()
to switch IO schedulers. There are a few problems with this:

- Since commit 1abec4fdbb142e3ccb6ce99832fae42129134a96,
  elevator_init() requires a zeroed out q->elevator
  pointer. The two existing in-kernel users don't do that.

- It will only work at initialization time, since using the
  above two-staged construct does not properly quisce the queue.

So add elevator_change() which takes care of this, and convert
the elv_iosched_store() sysfs interface to use this helper as well.

Reported-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Reported-by: Kevin Vigor <kevin@vigor.nu>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

9 years agofs/bio-integrity.c: return -ENOMEM on kmalloc failure
Andrew Morton [Mon, 23 Aug 2010 11:36:20 +0000]
fs/bio-integrity.c: return -ENOMEM on kmalloc failure

Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

9 years agobio-integrity.c: remove dependency on __GFP_NOFAIL
David Rientjes [Mon, 23 Aug 2010 11:35:09 +0000]
bio-integrity.c: remove dependency on __GFP_NOFAIL

The kmalloc() in bio_integrity_prep() is failable, so remove __GFP_NOFAIL
from its mask.

Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

9 years agoBLOCK: fix bio.bi_rw handling
Jiri Slaby [Thu, 12 Aug 2010 12:31:06 +0000]
BLOCK: fix bio.bi_rw handling

Return of the bi_rw tests is no longer bool after commit 74450be1. But
results of such tests are stored in bools. This doesn't fit in there
for some compilers (gcc 4.5 here), so either use !! magic to get real
bools or use ulong where the result is assigned somewhere.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

9 years agoblock: put dev->kobj in blk_register_queue fail path
Xiaotian Feng [Mon, 23 Aug 2010 10:30:29 +0000]
block: put dev->kobj in blk_register_queue fail path

kernel needs to kobject_put on dev->kobj if elv_register_queue fails.

Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Nikanth Karthikesan <knikanth@suse.de>
Cc: David Teigland <teigland@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

9 years agocciss: handle allocation failure
Dan Carpenter [Mon, 23 Aug 2010 10:28:15 +0000]
cciss: handle allocation failure

If kmalloc() fails then cleanup and return failure (-1).

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

9 years agocfq-iosched: Documentation help for new tunables
Vivek Goyal [Mon, 23 Aug 2010 10:25:29 +0000]
cfq-iosched: Documentation help for new tunables

Some documentation to provide help with tunables.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

9 years agocfq-iosched: blktrace print per slice sector stats
Vivek Goyal [Mon, 23 Aug 2010 10:25:03 +0000]
cfq-iosched: blktrace print per slice sector stats

o Divyesh had gotten rid of this code in the past. I want to re-introduce it
  back as it helps me a lot during debugging.

Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Reviewed-by: Divyesh Shah <dpshah@google.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

9 years agocfq-iosched: Implement tunable group_idle
Vivek Goyal [Mon, 23 Aug 2010 10:24:26 +0000]
cfq-iosched: Implement tunable group_idle

o Implement a new tunable group_idle, which allows idling on the group
  instead of a cfq queue. Hence one can set slice_idle = 0 and not idle
  on the individual queues but idle on the group. This way on fast storage
  we can get fairness between groups at the same time overall throughput
  improves.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

9 years agocfq-iosched: Do group share accounting in IOPS when slice_idle=0
Vivek Goyal [Mon, 23 Aug 2010 10:23:53 +0000]
cfq-iosched: Do group share accounting in IOPS when slice_idle=0

o Implement another CFQ mode where we charge group in terms of number
  of requests dispatched instead of measuring the time. Measuring in terms
  of time is not possible when we are driving deeper queue depths and there
  are requests from multiple cfq queues in the request queue.

o This mode currently gets activated if one sets slice_idle=0 and associated
  disk supports NCQ. Again the idea is that on an NCQ disk with idling disabled
  most of the queues will dispatch 1 or more requests and then cfq queue
  expiry happens and we don't have a way to measure time. So start providing
  fairness in terms of IOPS.

o Currently IOPS mode works only with cfq group scheduling. CFQ is following
  different scheduling algorithms for queue and group scheduling. These IOPS
  stats are used only for group scheduling hence in non-croup mode nothing
  should change.

o For CFQ group scheduling one can disable slice idling so that we don't idle
  on queue and drive deeper request queue depths (achieving better throughput),
  at the same time group idle is enabled so one should get service
  differentiation among groups.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

9 years agocfq-iosched: Do not idle if slice_idle=0
Vivek Goyal [Mon, 23 Aug 2010 10:23:33 +0000]
cfq-iosched: Do not idle if slice_idle=0

Do not idle either on cfq queue or service tree if slice_idle=0. User does
not want any queue or service tree idling. Currently even if slice_idle=0,
we were waiting for request to finish before expiring the queue and that
can lead to lower queue depths.

Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

9 years agocciss: disable doorbell reset on reset_devices
Stephen M. Cameron [Mon, 23 Aug 2010 09:02:17 +0000]
cciss: disable doorbell reset on reset_devices

The doorbell reset initially appears to work correctly,
the controller resets, comes up, some i/o can even be
done, but on at least some Smart Arrays in some servers,
it eventually causes a subsequent controller lockup due
to some kind of PCIe error, and kdump can end up leaving
the root filesystem in an unbootable state.  For this
reason, until the problem is fixed, or at least isolated
to certain hardware enough to be avoided, the doorbell
reset should not be used at all.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

9 years agoblkio: Fix return code for mkdir calls
Ciju Rajan K [Mon, 23 Aug 2010 08:56:30 +0000]
blkio: Fix return code for mkdir calls

If the cgroup hierarchy for blkio control groups is deeper than two
levels, kernel should not allow the creation of further levels. mkdir
system call does not except EINVAL as a return value. This patch
replaces EINVAL with more appropriate EPERM

Signed-off-by: Ciju Rajan K <ciju@linux.vnet.ibm.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

9 years agoMerge branch 'radix-tree' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/xfsdev
Linus Torvalds [Mon, 23 Aug 2010 02:55:14 +0000]
Merge branch 'radix-tree' of git://git./linux/kernel/git/dgc/xfsdev

* 'radix-tree' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/xfsdev:
  radix-tree: radix_tree_range_tag_if_tagged() can set incorrect tags
  radix-tree: clear all tags in radix_tree_node_rcu_free

9 years agoLinux 2.6.36-rc2
Linus Torvalds [Mon, 23 Aug 2010 00:43:29 +0000]
Linux 2.6.36-rc2

9 years agoradix-tree: radix_tree_range_tag_if_tagged() can set incorrect tags
Dave Chinner [Mon, 23 Aug 2010 00:33:53 +0000]
radix-tree: radix_tree_range_tag_if_tagged() can set incorrect tags

Commit ebf8aa44beed48cd17893a83d92a4403e5f9d9e2 ("radix-tree:
omplement function radix_tree_range_tag_if_tagged") does not safely
set tags on on intermediate tree nodes. The code walks down the tree
setting tags before it has fully resolved the path to the leaf under
the assumption there will be a leaf slot with the tag set in the
range it is searching.

Unfortunately, this is not a valid assumption - we can abort after
setting a tag on an intermediate node if we overrun the number of
tags we are allowed to set in a batch, or stop scanning because we
we have passed the last scan index before we reach a leaf slot with
the tag we are searching for set.

As a result, we can leave the function with tags set on intemediate
nodes which can be tripped over later by tag-based lookups. The
result of these stale tags is that lookup may end prematurely or
livelock because the lookup cannot make progress.

The fix for the problem involves reocrding the traversal path we
take to the leaf nodes, and only propagating the tags back up the
tree once the tag is set in the leaf node slot. We are already
recording the path for efficient traversal, so there is no
additional overhead to do the intermediately node tag setting in
this manner.

This fixes a radix tree lookup livelock triggered by the new
writeback sync livelock avoidance code introduced in commit
f446daaea9d4a420d16c606f755f3689dcb2d0ce ("mm: implement writeback
livelock avoidance using page tagging").

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Acked-by: Jan Kara <jack@suse.cz>

9 years agoradix-tree: clear all tags in radix_tree_node_rcu_free
Dave Chinner [Mon, 23 Aug 2010 00:33:19 +0000]
radix-tree: clear all tags in radix_tree_node_rcu_free

Commit f446daaea9d4a420d16c606f755f3689dcb2d0ce ("mm: implement
writeback livelock avoidance using page tagging") introduced a new
radix tree tag, increasing the number of tags in each node from 2 to
3. It did not, however, fix up the code in
radix_tree_node_rcu_free() that cleans up after radix_tree_shrink()
and hence could leave stray tags set in the new tag array.

The result is that the livelock avoidance code added in the the
above commit would hit stale tags when doing tag based lookups,
resulting in livelocks when trying to traverse the tree.

Fix this problem in radix_tree_node_rcu_free() so it doesn't happen
again in the future by using a loop to walk all the tags up to
RADIX_TREE_MAX_TAGS to clear the stray tags radix_tree_shrink()
leaves behind.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Acked-by: Nick Piggin <npiggin@kernel.dk>
Acked-by: Jan Kara <jack@suse.cz>

9 years agoMerge branch 'kvm-updates/2.6.36' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Linus Torvalds [Sun, 22 Aug 2010 18:27:36 +0000]
Merge branch 'kvm-updates/2.6.36' of git://git./virt/kvm/kvm

* 'kvm-updates/2.6.36' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: PIT: free irq source id in handling error path
  KVM: destroy workqueue on kvm_create_pit() failures
  KVM: fix poison overwritten caused by using wrong xstate size

9 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/anholt...
Linus Torvalds [Sun, 22 Aug 2010 18:03:27 +0000]
Merge branch 'for-linus' of git://git./linux/kernel/git/anholt/drm-intel

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/anholt/drm-intel: (58 commits)
  drm/i915,intel_agp: Add support for Sandybridge D0
  drm/i915: fix render pipe control notify on sandybridge
  agp/intel: set 40-bit dma mask on Sandybridge
  drm/i915: Remove the conflicting BUG_ON()
  drm/i915/suspend: s/IS_IRONLAKE/HAS_PCH_SPLIT/
  drm/i915/suspend: Flush register writes before busy-waiting.
  i915: disable DAC on Ironlake also when doing CRT load detection.
  drm/i915: wait for actual vblank, not just 20ms
  drm/i915: make sure eDP PLL is enabled at the right time
  drm/i915: fix VGA plane disable for Ironlake+
  drm/i915: eDP mode set sequence corrections
  drm/i915: add panel reset workaround
  drm/i915: Enable RC6 on Ironlake.
  drm/i915/sdvo: Only set is_lvds if we have a valid fixed mode.
  drm/i915: Set up a render context on Ironlake
  drm/i915 invalidate indirect state pointers at end of ring exec
  drm/i915: Wake-up wait_request() from elapsed hang-check (v2)
  drm/i915: Apply i830 errata for cursor alignment
  drm/i915: Only update i845/i865 CURBASE when disabled (v2)
  drm/i915: FBC is updated within set_base() so remove second call in mode_set()
  ...

9 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg...
Linus Torvalds [Sun, 22 Aug 2010 17:08:52 +0000]
Merge branch 'for-linus' of git://git./linux/kernel/git/penberg/slab-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
  slab: fix object alignment
  slub: add missing __percpu markup in mm/slub_def.h

9 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke...
Linus Torvalds [Sun, 22 Aug 2010 16:44:47 +0000]
Merge branch 'for-linus' of git://git./linux/kernel/git/ryusuke/nilfs2

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2:
  nilfs2: wait for discard to finish

9 years agodrm/i915,intel_agp: Add support for Sandybridge D0
Zhenyu Wang [Thu, 19 Aug 2010 01:46:16 +0000]
drm/i915,intel_agp: Add support for Sandybridge D0

Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

9 years agodrm/i915: fix render pipe control notify on sandybridge
Zhenyu Wang [Thu, 19 Aug 2010 01:46:15 +0000]
drm/i915: fix render pipe control notify on sandybridge

This one is missed in last pipe control fix for sandybridge,
that really unmask interrupt bit for notify in render engine IMR.

Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

9 years agoagp/intel: set 40-bit dma mask on Sandybridge
Zhenyu Wang [Thu, 19 Aug 2010 01:46:13 +0000]
agp/intel: set 40-bit dma mask on Sandybridge

Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

9 years agodrm/i915: Remove the conflicting BUG_ON()
Chris Wilson [Sun, 15 Aug 2010 09:52:34 +0000]
drm/i915: Remove the conflicting BUG_ON()

We now attempt to free "active" objects following a GPU hang as either
the GPU will be reset or the hang is permenant. In either case, the GPU
writes will not be flushed to main memory and it should be safe to
return that memory back to the system.

The BUG_ON(active) is thus overkill and can erroneously fire after a
EIO.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>

9 years agodrm/i915/suspend: s/IS_IRONLAKE/HAS_PCH_SPLIT/
Chris Wilson [Sat, 14 Aug 2010 13:41:23 +0000]
drm/i915/suspend: s/IS_IRONLAKE/HAS_PCH_SPLIT/

For the shared paths on the next generation chipsets.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>

9 years agodrm/i915/suspend: Flush register writes before busy-waiting.
Chris Wilson [Sat, 14 Aug 2010 13:41:22 +0000]
drm/i915/suspend: Flush register writes before busy-waiting.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>

9 years agoi915: disable DAC on Ironlake also when doing CRT load detection.
Dave Airlie [Wed, 4 Aug 2010 05:52:19 +0000]
i915: disable DAC on Ironlake also when doing CRT load detection.

Like on Sandybridge, disabling the DAC here when doing CRT load detect
avoids forever hangs waiting on the hardware.

test procedure on HP 2740p:
boot with no VGA plugged in, start X,
plug in VGA monitor (1280x1024)
chvt 3
machine hangs waiting forever.

Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

9 years agodrm/i915: wait for actual vblank, not just 20ms
Jesse Barnes [Wed, 18 Aug 2010 20:20:54 +0000]
drm/i915: wait for actual vblank, not just 20ms

Waiting for a hard coded 20ms isn't always enough to make sure a vblank
period has actually occurred, so add code to make sure we really have
passed through a vblank period (or that the pipe is off when disabling).

This prevents problems with mode setting and link training, and seems to
fix a bug like https://bugs.freedesktop.org/show_bug.cgi?id=29278, but
on an HP 8440p instead.  Hopefully also fixes
https://bugs.freedesktop.org/show_bug.cgi?id=29141.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>

9 years agoworkqueue: Add basic tracepoints to track workqueue execution
Arjan van de Ven [Sat, 21 Aug 2010 20:07:26 +0000]
workqueue: Add basic tracepoints to track workqueue execution

With the introduction of the new unified work queue thread pools,
we lost one feature: It's no longer possible to know which worker
is causing the CPU to wake out of idle. The result is that PowerTOP
now reports a lot of "kworker/a:b" instead of more readable results.

This patch adds a pair of tracepoints to the new workqueue code,
similar in style to the timer/hrtimer tracepoints.

With this pair of tracepoints, the next PowerTOP can correctly
report which work item caused the wakeup (and how long it took):

Interrupt (43)            i915      time   3.51ms    wakeups 141
Work      ieee80211_iface_work      time   0.81ms    wakeups  29
Work              do_dbs_timer      time   0.55ms    wakeups  24
Process                   Xorg      time  21.36ms    wakeups   4
Timer    sched_rt_period_timer      time   0.01ms    wakeups   1

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agoMerge git://git.infradead.org/mtd-2.6
Linus Torvalds [Sat, 21 Aug 2010 19:47:05 +0000]
Merge git://git.infradead.org/mtd-2.6

* git://git.infradead.org/mtd-2.6:
  mtd: nand: Fix probe of Samsung NAND chips
  mtd: nand: Fix regression in BBM detection
  pxa3xx: fix ns2cycle equation

9 years agoReplace Configure with Enable in description of MAXSMP
Samuel Thibault [Sat, 21 Aug 2010 19:32:41 +0000]
Replace Configure with Enable in description of MAXSMP

The "Configure" word tends to make user believe they have to say 'yes'
to be able to choose the number of procs/nodes.  "Enable" should be
unambiguous enough.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomm: make stack guard page logic use vm_prev pointer
Linus Torvalds [Fri, 20 Aug 2010 23:49:40 +0000]
mm: make stack guard page logic use vm_prev pointer

Like the mlock() change previously, this makes the stack guard check
code use vma->vm_prev to see what the mapping below the current stack
is, rather than have to look it up with find_vma().

Also, accept an abutting stack segment, since that happens naturally if
you split the stack with mlock or mprotect.

Tested-by: Ian Campbell <ijc@hellion.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomm: make the mlock() stack guard page checks stricter
Linus Torvalds [Fri, 20 Aug 2010 23:39:25 +0000]
mm: make the mlock() stack guard page checks stricter

If we've split the stack vma, only the lowest one has the guard page.
Now that we have a doubly linked list of vma's, checking this is trivial.

Tested-by: Ian Campbell <ijc@hellion.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomm: make the vma list be doubly linked
Linus Torvalds [Fri, 20 Aug 2010 23:24:55 +0000]
mm: make the vma list be doubly linked

It's a really simple list, and several of the users want to go backwards
in it to find the previous vma.  So rather than have to look up the
previous entry with 'find_vma_prev()' or something similar, just make it
doubly linked instead.

Tested-by: Ian Campbell <ijc@hellion.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomtd: nand: Fix probe of Samsung NAND chips
Tilman Sauerbeck [Fri, 20 Aug 2010 21:01:47 +0000]
mtd: nand: Fix probe of Samsung NAND chips

Apparently, the check for a 6-byte ID string introduced by commit
426c457a3216fac74e3d44dd39729b0689f4c7ab ("mtd: nand: extend NAND flash
detection to new MLC chips") is NOT sufficient to determine whether or
not a Samsung chip uses their new MLC detection scheme or the old,
standard scheme. This adds a condition to check cell type.

Signed-off-by: Tilman Sauerbeck <tilman@code-monkey.de>
Signed-off-by: Brian Norris <norris@broadcom.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: stable@kernel.org

9 years agoMerge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Fri, 20 Aug 2010 21:25:08 +0000]
Merge branch 'x86-fixes-for-linus' of git://git./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, apic: Fix apic=debug boot crash
  x86, hotplug: Serialize CPU hotplug to avoid bringup concurrency issues
  x86-32: Fix dummy trampoline-related inline stubs
  x86-32: Separate 1:1 pagetables from swapper_pg_dir
  x86, cpu: Fix regression in AMD errata checking code

9 years agoDocumentation: fix ozlabs.org mailing list address
Stephen Rothwell [Fri, 20 Aug 2010 09:56:31 +0000]
Documentation: fix ozlabs.org mailing list address

This list moved to lists.ozlabs.org quite some time ago.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agoMAINTAINERS: Fix ozlabs.org mailing list addresses
Stephen Rothwell [Fri, 20 Aug 2010 09:52:45 +0000]
MAINTAINERS: Fix ozlabs.org mailing list addresses

All these lists moved to lists.ozlabs.org quite a while ago.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agoDocumentation: kernel-locking: mutex_trylock cannot be used in interrupt context
Stefan Richter [Thu, 19 Aug 2010 21:13:43 +0000]
Documentation: kernel-locking: mutex_trylock cannot be used in interrupt context

Chapter 6 is right about mutex_trylock, but chapter 10 wasn't.  This error
was introduced during semaphore-to-mutex conversion of the Unreliable
guide.  :-)

If user context which performs mutex_lock() or mutex_trylock() is
preempted by interrupt context which performs mutex_trylock() on the same
mutex instance, a deadlock occurs.  This is because these functions do not
disable local IRQs when they operate on mutex->wait_lock.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agodrivers/scsi/qla4xxx: fix build
Andrew Morton [Thu, 19 Aug 2010 21:13:42 +0000]
drivers/scsi/qla4xxx: fix build

gcc-4.0.2:

  drivers/scsi/qla4xxx/ql4_os.c: In function 'qla4_8xxx_error_recovery':
  drivers/scsi/qla4xxx/ql4_glbl.h:135: sorry, unimplemented: inlining failed in call to 'qla4_8xxx_set_drv_active': function body not available
  drivers/scsi/qla4xxx/ql4_os.c:2377: sorry, unimplemented: called from here
  drivers/scsi/qla4xxx/ql4_glbl.h:135: sorry, unimplemented: inlining failed in call to 'qla4_8xxx_set_drv_active': function body not available
  drivers/scsi/qla4xxx/ql4_os.c:2393: sorry, unimplemented: called from here

Cc: Ravi Anand <ravi.anand@qlogic.com>
Cc: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agouml: fix compile error in dma_get_cache_alignment()
Miklos Szeredi [Thu, 19 Aug 2010 21:13:40 +0000]
uml: fix compile error in dma_get_cache_alignment()

Fix uml compile error:

  include/linux/dma-mapping.h:145: error: redefinition of 'dma_get_cache_alignment'
  arch/um/include/asm/dma-mapping.h:99: note: previous definition of 'dma_get_cache_alignment' was here

Introduced by commit 4565f0170dfc ("dma-mapping: unify
dma_get_cache_alignment implementations")

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agooom: __task_cred() need rcu_read_lock()
KOSAKI Motohiro [Thu, 19 Aug 2010 21:13:39 +0000]
oom: __task_cred() need rcu_read_lock()

dump_tasks() needs to hold the RCU read lock around its access of the
target task's UID.  To this end it should use task_uid() as it only needs
that one thing from the creds.

The fact that dump_tasks() holds tasklist_lock is insufficient to prevent the
target process replacing its credentials on another CPU.

Then, this patch change to call rcu_read_lock() explicitly.

===================================================
[ INFO: suspicious rcu_dereference_check() usage. ]
---------------------------------------------------
mm/oom_kill.c:410 invoked rcu_dereference_check() without protection!

other info that might help us debug this:

rcu_scheduler_active = 1, debug_locks = 1
4 locks held by kworker/1:2/651:
 #0:  (events){+.+.+.}, at: [<ffffffff8106aae7>]
process_one_work+0x137/0x4a0
 #1:  (moom_work){+.+...}, at: [<ffffffff8106aae7>]
process_one_work+0x137/0x4a0
 #2:  (tasklist_lock){.+.+..}, at: [<ffffffff810fafd4>]
out_of_memory+0x164/0x3f0
 #3:  (&(&p->alloc_lock)->rlock){+.+...}, at: [<ffffffff810fa48e>]
find_lock_task_mm+0x2e/0x70

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agooom: fix tasklist_lock leak
KOSAKI Motohiro [Thu, 19 Aug 2010 21:13:39 +0000]
oom: fix tasklist_lock leak

Commit 0aad4b3124 ("oom: fold __out_of_memory into out_of_memory")
introduced a tasklist_lock leak.  Then it caused following obvious
danger warnings and panic.

    ================================================
    [ BUG: lock held when returning to user space! ]
    ------------------------------------------------
    rsyslogd/1422 is leaving the kernel with locks still held!
    1 lock held by rsyslogd/1422:
     #0:  (tasklist_lock){.+.+.+}, at: [<ffffffff810faf64>] out_of_memory+0x164/0x3f0
    BUG: scheduling while atomic: rsyslogd/1422/0x00000002
    INFO: lockdep is turned off.

This patch fixes it.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agooom: fix NULL pointer dereference
KOSAKI Motohiro [Thu, 19 Aug 2010 21:13:38 +0000]
oom: fix NULL pointer dereference

Commit b940fd7035 ("oom: remove unnecessary code and cleanup") added an
unnecessary NULL pointer dereference.  remove it.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agodrivers/mmc/host/sdhci-s3c.c: use the correct mutex and card detect function
Kyungmin Park [Thu, 19 Aug 2010 21:13:37 +0000]
drivers/mmc/host/sdhci-s3c.c: use the correct mutex and card detect function

There's some merge problem between sdhic core and sdhci-s3c host.  After
mutex is changed to spinlock.  It needs to use use spin lock functions and
use the correct card detection function.

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agosdhci: add no hi-speed bit quirk support
Kyungmin Park [Thu, 19 Aug 2010 21:13:35 +0000]
sdhci: add no hi-speed bit quirk support

Some SDHCI controllers like s5pc110 don't have an HISPD bit in the HOSTCTL
register.

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agos5pc110: SDHCI-s3c support on s5pc110
Kyungmin Park [Thu, 19 Aug 2010 21:13:35 +0000]
s5pc110: SDHCI-s3c support on s5pc110

s5pc110 (aka s5pv210) uses the same SDHCI IP.

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agos5pc110: SDHCI-s3c can override host capabilities
Kyungmin Park [Thu, 19 Aug 2010 21:13:34 +0000]
s5pc110: SDHCI-s3c can override host capabilities

Each board can override the default sdhci host capabilities.
Some board has broken features by hardwares and support 8-bit bandwidth.

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agolib/radix-tree.c: fix overflow in radix_tree_range_tag_if_tagged()
Jan Kara [Thu, 19 Aug 2010 21:13:33 +0000]
lib/radix-tree.c: fix overflow in radix_tree_range_tag_if_tagged()

When radix_tree_maxindex() is ~0UL, it can happen that scanning overflows
index and tree traversal code goes astray reading memory until it hits
unreadable memory.  Check for overflow and exit in that case.

Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agorevert "hwmon: f71882fg: add support for the Fintek F71808E"
Andrew Morton [Thu, 19 Aug 2010 21:13:31 +0000]
revert "hwmon: f71882fg: add support for the Fintek F71808E"

Revert commit 7721fea3d0fd93fb4d000eb737b444369358d6d3 ("hwmon:
f71882fg: add support for the Fintek F71808E").

Hans said:

: A second review after I've received a data sheet for this device from
: Fintek has turned up a few bugs.
:
: Unfortunately Giel (nor I) have time to fix this in time for the 2.6.36
: cycle.  Therefor I would like to see this patch reverted as not having any
: support for the hwmon function of this superio chip is better then having
: unreliable support.

Cc: Giel van Schijndel <me@mortis.eu>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agokfifo: add explicit error checking in all the examples
Andrea Righi [Thu, 19 Aug 2010 21:13:30 +0000]
kfifo: add explicit error checking in all the examples

Provide a check in all the kfifo examples to validate the correct
execution of each testcase.

Signed-off-by: Andrea Righi <arighi@develer.com>
Acked-by: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agokfifo: fix a memory leak in dma example
Andrea Righi [Thu, 19 Aug 2010 21:13:30 +0000]
kfifo: fix a memory leak in dma example

We use a dynamically allocated kfifo in the dma example, so we need to
free it when unloading the module.

Signed-off-by: Andrea Righi <arighi@develer.com>
Acked-by: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agokfifo: fix kernel BUG in dma example
Andrea Righi [Thu, 19 Aug 2010 21:13:29 +0000]
kfifo: fix kernel BUG in dma example

The scatterlist is used uninitialized in kfifo_dma_in_prepare().  This
triggers the following bug if CONFIG_DEBUG_SG=y:

  ------------[ cut here ]------------
  kernel BUG at include/linux/scatterlist.h:65!
  invalid opcode: 0000 [#1] PREEMPT SMP
  ...
  Call Trace:
   [<ffffffff810a1eab>] setup_sgl+0x6b/0xe0
   [<ffffffffa03d7000>] ? example_init+0x0/0x265 [dma_example]
   [<ffffffff810a2021>] __kfifo_dma_in_prepare+0x21/0x30
   [<ffffffffa03d7124>] example_init+0x124/0x265 [dma_example]
   [<ffffffff810f9c55>] ? trace_module_notify+0x25/0x370
   [<ffffffff81110c6e>] ? free_pages_prepare+0x11e/0x1e0
   [<ffffffff8106f2b1>] ? get_parent_ip+0x11/0x50
   [<ffffffff810f9c55>] ? trace_module_notify+0x25/0x370
   [<ffffffff810b65fd>] ? trace_hardirqs_on+0xd/0x10
   [<ffffffff814beade>] ? mutex_unlock+0xe/0x10
   [<ffffffff810f9c71>] ? trace_module_notify+0x41/0x370
   [<ffffffff810a77d5>] ? __blocking_notifier_call_chain+0x45/0x80
   [<ffffffff81137b7a>] ? vfree+0x2a/0x30
   [<ffffffff810a6ac3>] ? up_read+0x23/0x40
   [<ffffffff810a77f5>] ? __blocking_notifier_call_chain+0x65/0x80
   [<ffffffff810001e3>] do_one_initcall+0x43/0x180
   [<ffffffff810c577a>] sys_init_module+0xba/0x200
   [<ffffffff8103819b>] system_call_fastpath+0x16/0x1b
  RIP  [<ffffffff810a1e31>] setup_sgl_buf+0x1a1/0x1b0
   RSP <ffff88006720dc98>
  ---[ end trace a72b979fd3c1d3a5 ]---

Add the proper initialization to avoid the bug.

Signed-off-by: Andrea Righi <arighi@develer.com>
Acked-by: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agokfifo: add explicit error checking in byte stream example
Andrea Righi [Thu, 19 Aug 2010 21:13:29 +0000]
kfifo: add explicit error checking in byte stream example

Provide a static array of expected items that kfifo should contain at the
end of the test to validate it.

Signed-off-by: Andrea Righi <arighi@develer.com>
Cc: Stefani Seibold <stefani@seibold.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agokfifo: add kfifo_skip() testcase
Andrea Righi [Thu, 19 Aug 2010 21:13:28 +0000]
kfifo: add kfifo_skip() testcase

Add a testcase for kfifo_skip() to the byte stream fifo example.

Signed-off-by: Andrea Righi <arighi@develer.com>
Cc: Greg KH <greg@kroah.com>
Acked-by: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agokfifo: implement missing __kfifo_skip_r()
Andrea Righi [Thu, 19 Aug 2010 21:13:27 +0000]
kfifo: implement missing __kfifo_skip_r()

kfifo_skip() is currently broken, due to the missing of the internal
helper function.  Add it.

Signed-off-by: Andrea Righi <arighi@develer.com>
Cc: Greg KH <greg@kroah.com>
Acked-by: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomatroxfb: fix incorrect use of memcpy_toio()
Ondrej Zary [Thu, 19 Aug 2010 21:13:25 +0000]
matroxfb: fix incorrect use of memcpy_toio()

Screen is completely corrupted since 2.6.34.  Bisection revealed that it's
caused by commit 6175ddf06b61720 ("x86: Clean up mem*io functions.").

H.  Peter Anvin explained that memcpy_toio() does not copy data in 32bit
chunks anymore on x86.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Petr Vandrovec <vandrove@vc.cvut.cz>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: <stable@kernel.org> [2.6.34.x, 2.6.35.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agox86, apic: Fix apic=debug boot crash
Daniel Kiper [Thu, 19 Aug 2010 22:46:16 +0000]
x86, apic: Fix apic=debug boot crash

Fix a boot crash when apic=debug is used and the APIC is
not properly initialized.

This issue appears during Xen Dom0 kernel boot but the
fix is generic and the crash could occur on real hardware
as well.

Signed-off-by: Daniel Kiper <dkiper@net-space.pl>
Cc: xen-devel@lists.xensource.com
Cc: konrad.wilk@oracle.com
Cc: jeremy@goop.org
Cc: <stable@kernel.org> # .35.x, .34.x, .33.x, .32.x
LKML-Reference: <20100819224616.GB9967@router-fw-old.local.net-space.pl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

9 years agox86, hotplug: Serialize CPU hotplug to avoid bringup concurrency issues
Borislav Petkov [Thu, 19 Aug 2010 18:10:29 +0000]
x86, hotplug: Serialize CPU hotplug to avoid bringup concurrency issues

When testing cpu hotplug code on 32-bit we kept hitting the "CPU%d:
Stuck ??" message due to multiple cores concurrently accessing the
cpu_callin_mask, among others.

Since these codepaths are not protected from concurrent access due to
the fact that there's no sane reason for making an already complex
code unnecessarily more complex - we hit the issue only when insanely
switching cores off- and online - serialize hotplugging cores on the
sysfs level and be done with it.

[ v2.1: fix !HOTPLUG_CPU build ]

Cc: <stable@kernel.org>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <20100819181029.GC17171@aftab>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

9 years agoMerge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Thu, 19 Aug 2010 16:06:49 +0000]
Merge branch 'perf-fixes-for-linus' of git://git./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:
  kprobes/x86: Fix the return address of multiple kretprobes
  perf tools: Fix build error on read only source.
  perf, x86: Fix Intel-nhm PMU programming errata workaround

9 years agomtd: nand: Fix regression in BBM detection
Brian Norris [Wed, 18 Aug 2010 18:25:04 +0000]
mtd: nand: Fix regression in BBM detection

Commit c7b28e25cb9beb943aead770ff14551b55fa8c79 ("mtd: nand: refactor BB
marker detection") caused a regression in detection of factory-set bad
block markers, especially for certain small-page NAND. This fix removes
some unneeded constraints on using NAND_SMALL_BADBLOCK_POS, making the
detection code more correct.

This regression can be seen, for example, in Hynix HY27US081G1M and
similar.

Signed-off-by: Brian Norris <norris@broadcom.com>
Tested-by: Michael Guntsche <mike@it-loops.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

9 years agokprobes/x86: Fix the return address of multiple kretprobes
KUMANO Syuhei [Sun, 15 Aug 2010 06:18:04 +0000]
kprobes/x86: Fix the return address of multiple kretprobes

Fix the return address of subsequent kretprobes when multiple
kretprobes are set on the same function.

For example:

 # cd /sys/kernel/debug/tracing
 # echo "r:event1 sys_symlink" > kprobe_events
 # echo "r:event2 sys_symlink" >> kprobe_events
 # echo 1 > events/kprobes/enable
 # ln -s /tmp/foo /tmp/bar

(without this patch)

 # cat trace
              ln-897   [000] 20404.133727: event1: (kretprobe_trampoline+0x0/0x4c <- sys_symlink)
              ln-897   [000] 20404.133747: event2: (system_call_fastpath+0x16/0x1b <- sys_symlink)

(with this patch)

 # cat trace
              ln-740   [000] 13799.491076: event1: (system_call_fastpath+0x16/0x1b <- sys_symlink)
              ln-740   [000] 13799.491096: event2: (system_call_fastpath+0x16/0x1b <- sys_symlink)

Signed-off-by: KUMANO Syuhei <kumano.prog@gmail.com>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
LKML-Reference: <1281853084.3254.11.camel@camp10-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

9 years agoMerge branch 'perf/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/acme...
Ingo Molnar [Thu, 19 Aug 2010 10:25:29 +0000]
Merge branch 'perf/urgent' of git://git./linux/kernel/git/acme/linux-2.6 into perf/urgent

9 years agoMerge branch 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6
Linus Torvalds [Wed, 18 Aug 2010 22:45:23 +0000]
Merge branch 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6

* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
  NFS: Fix an Oops in the NFSv4 atomic open code
  NFS: Fix the selection of security flavours in Kconfig
  NFS: fix the return value of nfs_file_fsync()
  rpcrdma: Fix SQ size calculation when memreg is FRMR
  xprtrdma: Do not truncate iova_start values in frmr registrations.
  nfs: Remove redundant NULL check upon kfree()
  nfs: Add "lookupcache" to displayed mount options
  NFS: allow close-to-open cache semantics to apply to root of NFS filesystem
  SUNRPC: fix NFS client over TCP hangs due to packet loss (Bug 16494)

9 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
Linus Torvalds [Wed, 18 Aug 2010 22:29:38 +0000]
Merge branch 'for-linus' of git://git./linux/kernel/git/jikos/hid

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  USB HID: Add ID for eGalax Multitouch used in JooJoo tablet
  HID: hiddev: fix memory corruption due to invalid intfdata
  HID: hiddev: protect against disconnect/NULL-dereference race
  HID: picolcd: correct ordering of framebuffer freeing
  HID: picolcd: testing the wrong variable

9 years agoMerge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6
Linus Torvalds [Wed, 18 Aug 2010 20:27:41 +0000]
Merge branch 'release' of git://git./linux/kernel/git/aegl/linux-2.6

* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
  [IA64] Fix build error: conflicting types for ‘sys_execve’

9 years agodrm/i915: make sure eDP PLL is enabled at the right time
Jesse Barnes [Fri, 13 Aug 2010 22:43:26 +0000]
drm/i915: make sure eDP PLL is enabled at the right time

We need to make sure the eDP PLL is enabled before the pipes or planes,
so do it as part of the DP prepare mode set function.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

9 years agodrm/i915: fix VGA plane disable for Ironlake+
Jesse Barnes [Fri, 13 Aug 2010 22:11:26 +0000]
drm/i915: fix VGA plane disable for Ironlake+

We need to use I/O port instructions to access VGA registers on
Ironlake+, and it doesn't hurt on other platforms, so switch the VGA
plane disable function over to using them.  Move it to init time as well
while we're at it, no need to repeatedly disable the VGA plane with
every mode set and DPMS event.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

9 years agodrm/i915: eDP mode set sequence corrections
Jesse Barnes [Wed, 11 Aug 2010 17:06:44 +0000]
drm/i915: eDP mode set sequence corrections

We should disable the panel first when shutting down an eDP link.  And
when turning one on, the panel needs to be enabled before link training
or eDP I/O won't be enabled.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

9 years agodrm/i915: add panel reset workaround
Jesse Barnes [Wed, 11 Aug 2010 17:04:43 +0000]
drm/i915: add panel reset workaround

Ironlake requires that we clear the reset panel bit during power
sequences and restore it afterwards.  Uncondtionally add code to do that
since it should be harmless on SNB+.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

9 years agox86-32: Fix dummy trampoline-related inline stubs
H. Peter Anvin [Wed, 18 Aug 2010 18:42:23 +0000]
x86-32: Fix dummy trampoline-related inline stubs

Fix dummy inline stubs for trampoline-related functions when no
trampolines exist (until we get rid of the no-trampoline case
entirely.)

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Cc: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <4C6C294D.3030404@zytor.com>

9 years agoFix the declaration of sys_execve() in asm-generic/syscalls.h
David Howells [Wed, 18 Aug 2010 17:55:33 +0000]
Fix the declaration of sys_execve() in asm-generic/syscalls.h

Fix the declaration of sys_execve() in asm-generic/syscalls.h to have
various consts applied to its pointers.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years ago[IA64] Fix build error: conflicting types for ‘sys_execve’
Tony Luck [Wed, 18 Aug 2010 17:17:44 +0000]
[IA64] Fix build error: conflicting types for ‘sys_execve’

arch/ia64/kernel/process.c:636: error: conflicting types for ‘sys_execve’

commit d7627467b7a8dd6944885290a03a07ceb28c10eb
Make do_execve() take a const filename pointer

Missed the declaration of sys_execve in the ia64 asm/unistd.h (perhaps
because there is no reason for it to be there ... it might be a left over
from the COMPAT code?). Just delete the conflicting version.

Signed-off-by: Tony Luck <tony.luck@intel.com>

9 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
Linus Torvalds [Wed, 18 Aug 2010 16:35:08 +0000]
Merge branch 'for-linus' of git://git./linux/kernel/git/viro/vfs-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  fs: brlock vfsmount_lock
  fs: scale files_lock
  lglock: introduce special lglock and brlock spin locks
  tty: fix fu_list abuse
  fs: cleanup files_lock locking
  fs: remove extra lookup in __lookup_hash
  fs: fs_struct rwlock to spinlock
  apparmor: use task path helpers
  fs: dentry allocation consolidation
  fs: fix do_lookup false negative
  mbcache: Limit the maximum number of cache entries
  hostfs ->follow_link() braino
  hostfs: dumb (and usually harmless) tpyo - strncpy instead of strlcpy
  remove SWRITE* I/O types
  kill BH_Ordered flag
  vfs: update ctime when changing the file's permission by setfacl
  cramfs: only unlock new inodes
  fix reiserfs_evict_inode end_writeback second call

9 years agommc: build fix: mmc_pm_notify is only available with CONFIG_PM=y
Uwe Kleine-König [Wed, 18 Aug 2010 16:25:38 +0000]
mmc: build fix: mmc_pm_notify is only available with CONFIG_PM=y

This fixes a build breakage introduced by commit 4c2ef25fe0b8 ("mmc: fix
all hangs related to mmc/sd card insert/removal during suspend/resume")

Cc: David Brownell <david-b@pacbell.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: linux-mmc@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Acked-by: Maxim Levitsky <maximlevitsky@gmail.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agoperf tools: Fix build error on read only source.
Kusanagi Kouichi [Wed, 18 Aug 2010 16:32:37 +0000]
perf tools: Fix build error on read only source.

Parts of the build process were generating files outside the specified
O= directory, causing the build to fail on systems where the sources are
in a read only file system.

Fix it by using $(OUTPUT) on these locations.

Also check that $(OUTPUT) actually exists, just like the top level
kernel Makefile does. Otherwise the failure message emitted is
completely misleading.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20100817140841.0859362C03A@msa106.auone-net.jp>
Signed-off-by: Kusanagi Kouichi <slash@ac.auone-net.jp>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

9 years agoMerge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Wed, 18 Aug 2010 16:32:13 +0000]
Merge branch 'perf-fixes-for-linus' of git://git./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 tools: Fix build on POSIX shells
  latencytop: Fix kconfig dependency warnings
  perf annotate tui: Fix exit and RIGHT keys handling
  tracing: Sanitize value returned from write(trace_marker, "...", len)
  tracing/events: Convert format output to seq_file
  tracing: Extend recordmcount to better support Blackfin mcount
  tracing: Fix ring_buffer_read_page reading out of page boundary
  tracing: Fix an unallocated memory access in function_graph

9 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6
Linus Torvalds [Wed, 18 Aug 2010 16:30:08 +0000]
Merge branch 'for-linus' of git://git./linux/kernel/git/tiwai/sound-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ALSA: emu10k1 - delay the PCM interrupts (add pcm_irq_delay parameter)
  ALSA: hda - Fix ALC680 base model capture
  ASoC: Remove DSP mode support for WM8776
  ALSA: hda - Add quirk for Dell Vostro 1220
  ALSA: riptide - Fix detection / load of firmware files

9 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu
Linus Torvalds [Wed, 18 Aug 2010 16:27:10 +0000]
Merge branch 'for-linus' of git://git./linux/kernel/git/gerg/m68knommu

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu:
  m68knommu: include sched.h in ColdFire/SPI driver
  m68knommu: formatting of pointers in printk()
  m68knommu: arch/m68k/include/asm/ide.h fix for nommu

9 years agoMerge branch 'for-linus' of git://neil.brown.name/md
Linus Torvalds [Wed, 18 Aug 2010 16:26:42 +0000]
Merge branch 'for-linus' of git://neil.brown.name/md

* 'for-linus' of git://neil.brown.name/md:
  md raid-1/10 Fix bio_rw bit manipulations again
  md: provide appropriate return value for spare_active functions.
  md: Notify sysfs when RAID1/5/10 disk is In_sync.
  Update recovery_offset even when external metadata is used.

9 years agoMerge branch 'merge-devicetree' of git://git.secretlab.ca/git/linux-2.6
Linus Torvalds [Wed, 18 Aug 2010 16:26:17 +0000]
Merge branch 'merge-devicetree' of git://git.secretlab.ca/git/linux-2.6

* 'merge-devicetree' of git://git.secretlab.ca/git/linux-2.6:
  spi.h: missing kernel-doc notation, please fix
  of: fix missing headers for of_address_to_resource() in MTD and SysACE drivers
  of: Fix missing includes
  ata: update for of_device to platform_device replacement
  microblaze: Fix of: eliminate of_device->node and dev_archdata->{of,prom}_node
  microblaze: Fix of/address: Merge all of the bus translation code
  booting-without-of: Remove nonexistent chapters from TOC, fix numbering

9 years agox86-32: Separate 1:1 pagetables from swapper_pg_dir
Joerg Roedel [Mon, 16 Aug 2010 12:38:33 +0000]
x86-32: Separate 1:1 pagetables from swapper_pg_dir

This patch fixes machine crashes which occur when heavily exercising the
CPU hotplug codepaths on a 32-bit kernel. These crashes are caused by
AMD Erratum 383 and result in a fatal machine check exception. Here's
the scenario:

1. On 32-bit, the swapper_pg_dir page table is used as the initial page
table for booting a secondary CPU.

2. To make this work, swapper_pg_dir needs a direct mapping of physical
memory in it (the low mappings). By adding those low, large page (2M)
mappings (PAE kernel), we create the necessary conditions for Erratum
383 to occur.

3. Other CPUs which do not participate in the off- and onlining game may
use swapper_pg_dir while the low mappings are present (when leave_mm is
called). For all steps below, the CPU referred to is a CPU that is using
swapper_pg_dir, and not the CPU which is being onlined.

4. The presence of the low mappings in swapper_pg_dir can result
in TLB entries for addresses below __PAGE_OFFSET to be established
speculatively. These TLB entries are marked global and large.

5. When the CPU with such TLB entry switches to another page table, this
TLB entry remains because it is global.

6. The process then generates an access to an address covered by the
above TLB entry but there is a permission mismatch - the TLB entry
covers a large global page not accessible to userspace.

7. Due to this permission mismatch a new 4kb, user TLB entry gets
established. Further, Erratum 383 provides for a small window of time
where both TLB entries are present. This results in an uncorrectable
machine check exception signalling a TLB multimatch which panics the
machine.

There are two ways to fix this issue:

        1. Always do a global TLB flush when a new cr3 is loaded and the
        old page table was swapper_pg_dir. I consider this a hack hard
        to understand and with performance implications

        2. Do not use swapper_pg_dir to boot secondary CPUs like 64-bit
        does.

This patch implements solution 2. It introduces a trampoline_pg_dir
which has the same layout as swapper_pg_dir with low_mappings. This page
table is used as the initial page table of the booting CPU. Later in the
bringup process, it switches to swapper_pg_dir and does a global TLB
flush. This fixes the crashes in our test cases.

-v2: switch to swapper_pg_dir right after entering start_secondary() so
that we are able to access percpu data which might not be mapped in the
trampoline page table.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
LKML-Reference: <20100816123833.GB28147@aftab>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

9 years agox86, cpu: Fix regression in AMD errata checking code
Hans Rosenfeld [Wed, 18 Aug 2010 14:19:50 +0000]
x86, cpu: Fix regression in AMD errata checking code

A bug in the family-model-stepping matching code caused the presence of
errata to go undetected when OSVW was not used. This causes hangs on
some K8 systems because the E400 workaround is not enabled.

Signed-off-by: Hans Rosenfeld <hans.rosenfeld@amd.com>
LKML-Reference: <1282141190-930137-1-git-send-email-hans.rosenfeld@amd.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

9 years agonilfs2: wait for discard to finish
Ryusuke Konishi [Wed, 18 Aug 2010 12:11:11 +0000]
nilfs2: wait for discard to finish

nilfs_discard_segment() doesn't wait for completion of discard
requests.  This specifies BLKDEV_IFL_WAIT flag when calling
blkdev_issue_discard() in order to fix the sync failure.

Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Christoph Hellwig <hch@lst.de>

9 years agoNFS: Fix an Oops in the NFSv4 atomic open code
Trond Myklebust [Wed, 18 Aug 2010 13:25:42 +0000]
NFS: Fix an Oops in the NFSv4 atomic open code

Adam Lackorzynski reports:

with 2.6.35.2 I'm getting this reproducible Oops:

[  110.825396] BUG: unable to handle kernel NULL pointer dereference at
(null)
[  110.828638] IP: [<ffffffff811247b7>] encode_attrs+0x1a/0x2a4
[  110.828638] PGD be89f067 PUD bf18f067 PMD 0
[  110.828638] Oops: 0000 [#1] SMP
[  110.828638] last sysfs file: /sys/class/net/lo/operstate
[  110.828638] CPU 2
[  110.828638] Modules linked in: rtc_cmos rtc_core rtc_lib amd64_edac_mod
i2c_amd756 edac_core i2c_core dm_mirror dm_region_hash dm_log dm_snapshot
sg sr_mod usb_storage ohci_hcd mptspi tg3 mptscsih mptbase usbcore nls_base
[last unloaded: scsi_wait_scan]
[  110.828638]
[  110.828638] Pid: 11264, comm: setchecksum Not tainted 2.6.35.2 #1
[  110.828638] RIP: 0010:[<ffffffff811247b7>]  [<ffffffff811247b7>]
encode_attrs+0x1a/0x2a4
[  110.828638] RSP: 0000:ffff88003bf5b878  EFLAGS: 00010296
[  110.828638] RAX: ffff8800bddb48a8 RBX: ffff88003bf5bb18 RCX:
0000000000000000
[  110.828638] RDX: ffff8800be258800 RSI: 0000000000000000 RDI:
ffff88003bf5b9f8
[  110.828638] RBP: 0000000000000000 R08: ffff8800bddb48a8 R09:
0000000000000004
[  110.828638] R10: 0000000000000003 R11: ffff8800be779000 R12:
ffff8800be258800
[  110.828638] R13: ffff88003bf5b9f8 R14: ffff88003bf5bb20 R15:
ffff8800be258800
[  110.828638] FS:  0000000000000000(0000) GS:ffff880041e00000(0063)
knlGS:00000000556bd6b0
[  110.828638] CS:  0010 DS: 002b ES: 002b CR0: 000000008005003b
[  110.828638] CR2: 0000000000000000 CR3: 00000000be8ef000 CR4:
00000000000006e0
[  110.828638] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[  110.828638] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7:
0000000000000400
[  110.828638] Process setchecksum (pid: 11264, threadinfo
ffff88003bf5a000, task ffff88003f232210)
[  110.828638] Stack:
[  110.828638]  0000000000000000 ffff8800bfbcf920 0000000000000000
0000000000000ffe
[  110.828638] <0> 0000000000000000 0000000000000000 0000000000000000
0000000000000000
[  110.828638] <0> 0000000000000000 0000000000000000 0000000000000000
0000000000000000
[  110.828638] Call Trace:
[  110.828638]  [<ffffffff81124c1f>] ? nfs4_xdr_enc_setattr+0x90/0xb4
[  110.828638]  [<ffffffff81371161>] ? call_transmit+0x1c3/0x24a
[  110.828638]  [<ffffffff813774d9>] ? __rpc_execute+0x78/0x22a
[  110.828638]  [<ffffffff81371a91>] ? rpc_run_task+0x21/0x2b
[  110.828638]  [<ffffffff81371b7e>] ? rpc_call_sync+0x3d/0x5d
[  110.828638]  [<ffffffff8111e284>] ? _nfs4_do_setattr+0x11b/0x147
[  110.828638]  [<ffffffff81109466>] ? nfs_init_locked+0x0/0x32
[  110.828638]  [<ffffffff810ac521>] ? ifind+0x4e/0x90
[  110.828638]  [<ffffffff8111e2fb>] ? nfs4_do_setattr+0x4b/0x6e
[  110.828638]  [<ffffffff8111e634>] ? nfs4_do_open+0x291/0x3a6
[  110.828638]  [<ffffffff8111ed81>] ? nfs4_open_revalidate+0x63/0x14a
[  110.828638]  [<ffffffff811056c4>] ? nfs_open_revalidate+0xd7/0x161
[  110.828638]  [<ffffffff810a2de4>] ? do_lookup+0x1a4/0x201
[  110.828638]  [<ffffffff810a4733>] ? link_path_walk+0x6a/0x9d5
[  110.828638]  [<ffffffff810a42b6>] ? do_last+0x17b/0x58e
[  110.828638]  [<ffffffff810a5fbe>] ? do_filp_open+0x1bd/0x56e
[  110.828638]  [<ffffffff811cd5e0>] ? _atomic_dec_and_lock+0x30/0x48
[  110.828638]  [<ffffffff810a9b1b>] ? dput+0x37/0x152
[  110.828638]  [<ffffffff810ae063>] ? alloc_fd+0x69/0x10a
[  110.828638]  [<ffffffff81099f39>] ? do_sys_open+0x56/0x100
[  110.828638]  [<ffffffff81027a22>] ? ia32_sysret+0x0/0x5
[  110.828638] Code: 83 f1 01 e8 f5 ca ff ff 48 83 c4 50 5b 5d 41 5c c3 41
57 41 56 41 55 49 89 fd 41 54 49 89 d4 55 48 89 f5 53 48 81 ec 18 01 00 00
<8b> 06 89 c2 83 e2 08 83 fa 01 19 db 83 e3 f8 83 c3 18 a8 01 8d
[  110.828638] RIP  [<ffffffff811247b7>] encode_attrs+0x1a/0x2a4
[  110.828638]  RSP <ffff88003bf5b878>
[  110.828638] CR2: 0000000000000000
[  112.840396] ---[ end trace 95282e83fd77358f ]---

We need to ensure that the O_EXCL flag is turned off if the user doesn't
set O_CREAT.

Cc: stable@kernel.org
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

9 years agoMerge branch 'fix/asoc' into for-linus
Takashi Iwai [Wed, 18 Aug 2010 13:22:18 +0000]
Merge branch 'fix/asoc' into for-linus

9 years agoMerge branch 'fix/hda' into for-linus
Takashi Iwai [Wed, 18 Aug 2010 13:22:15 +0000]
Merge branch 'fix/hda' into for-linus

9 years agoALSA: emu10k1 - delay the PCM interrupts (add pcm_irq_delay parameter)
Jaroslav Kysela [Wed, 18 Aug 2010 12:08:17 +0000]
ALSA: emu10k1 - delay the PCM interrupts (add pcm_irq_delay parameter)

With some hardware combinations, the PCM interrupts are acknowledged
before the period boundary from the emu10k1 chip. The midlevel PCM code
gets confused and the playback stream is interrupted.

It seems that the interrupt processing shift by 2 samples is enough
to fix this issue. This default value does not harm other,
non-affected hardware.

More information: Kernel bugzilla bug#16300

[A copmile warning fixed by tiwai]

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

9 years agofs: brlock vfsmount_lock
Nick Piggin [Tue, 17 Aug 2010 18:37:39 +0000]
fs: brlock vfsmount_lock

fs: brlock vfsmount_lock

Use a brlock for the vfsmount lock. It must be taken for write whenever
modifying the mount hash or associated fields, and may be taken for read when
performing mount hash lookups.

A new lock is added for the mnt-id allocator, so it doesn't need to take
the heavy vfsmount write-lock.

The number of atomics should remain the same for fastpath rlock cases, though
code would be slightly slower due to per-cpu access. Scalability is not not be
much improved in common cases yet, due to other locks (ie. dcache_lock) getting
in the way. However path lookups crossing mountpoints should be one case where
scalability is improved (currently requiring the global lock).

The slowpath is slower due to use of brlock. On a 64 core, 64 socket, 32 node
Altix system (high latency to remote nodes), a simple umount microbenchmark
(mount --bind mnt mnt2 ; umount mnt2 loop 1000 times), before this patch it
took 6.8s, afterwards took 7.1s, about 5% slower.

Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

9 years agofs: scale files_lock
Nick Piggin [Tue, 17 Aug 2010 18:37:38 +0000]
fs: scale files_lock

fs: scale files_lock

Improve scalability of files_lock by adding per-cpu, per-sb files lists,
protected with an lglock. The lglock provides fast access to the per-cpu lists
to add and remove files. It also provides a snapshot of all the per-cpu lists
(although this is very slow).

One difficulty with this approach is that a file can be removed from the list
by another CPU. We must track which per-cpu list the file is on with a new
variale in the file struct (packed into a hole on 64-bit archs). Scalability
could suffer if files are frequently removed from different cpu's list.

However loads with frequent removal of files imply short interval between
adding and removing the files, and the scheduler attempts to avoid moving
processes too far away. Also, even in the case of cross-CPU removal, the
hardware has much more opportunity to parallelise cacheline transfers with N
cachelines than with 1.

A worst-case test of 1 CPU allocating files subsequently being freed by N CPUs
degenerates to contending on a single lock, which is no worse than before. When
more than one CPU are allocating files, even if they are always freed by
different CPUs, there will be more parallelism than the single-lock case.

Testing results:

On a 2 socket, 8 core opteron, I measure the number of times the lock is taken
to remove the file, the number of times it is removed by the same CPU that
added it, and the number of times it is removed by the same node that added it.

Booting:    locks=  25049 cpu-hits=  23174 (92.5%) node-hits=  23945 (95.6%)
kbuild -j16 locks=2281913 cpu-hits=2208126 (96.8%) node-hits=2252674 (98.7%)
dbench 64   locks=4306582 cpu-hits=4287247 (99.6%) node-hits=4299527 (99.8%)

So a file is removed from the same CPU it was added by over 90% of the time.
It remains within the same node 95% of the time.

Tim Chen ran some numbers for a 64 thread Nehalem system performing a compile.

                throughput
2.6.34-rc2      24.5
+patch          24.9

                us      sys     idle    IO wait (in %)
2.6.34-rc2      51.25   28.25   17.25   3.25
+patch          53.75   18.5    19      8.75

So significantly less CPU time spent in kernel code, higher idle time and
slightly higher throughput.

Single threaded performance difference was within the noise of microbenchmarks.
That is not to say penalty does not exist, the code is larger and more memory
accesses required so it will be slightly slower.

Cc: linux-kernel@vger.kernel.org
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

9 years agolglock: introduce special lglock and brlock spin locks
Nick Piggin [Tue, 17 Aug 2010 18:37:37 +0000]
lglock: introduce special lglock and brlock spin locks

lglock: introduce special lglock and brlock spin locks

This patch introduces "local-global" locks (lglocks). These can be used to:

- Provide fast exclusive access to per-CPU data, with exclusive access to
  another CPU's data allowed but possibly subject to contention, and to provide
  very slow exclusive access to all per-CPU data.
- Or to provide very fast and scalable read serialisation, and to provide
  very slow exclusive serialisation of data (not necessarily per-CPU data).

Brlocks are also implemented as a short-hand notation for the latter use
case.

Thanks to Paul for local/global naming convention.

Cc: linux-kernel@vger.kernel.org
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

9 years agotty: fix fu_list abuse
Nick Piggin [Tue, 17 Aug 2010 18:37:36 +0000]
tty: fix fu_list abuse

tty: fix fu_list abuse

tty code abuses fu_list, which causes a bug in remount,ro handling.

If a tty device node is opened on a filesystem, then the last link to the inode
removed, the filesystem will be allowed to be remounted readonly. This is
because fs_may_remount_ro does not find the 0 link tty inode on the file sb
list (because the tty code incorrectly removed it to use for its own purpose).
This can result in a filesystem with errors after it is marked "clean".

Taking idea from Christoph's initial patch, allocate a tty private struct
at file->private_data and put our required list fields in there, linking
file and tty. This makes tty nodes behave the same way as other device nodes
and avoid meddling with the vfs, and avoids this bug.

The error handling is not trivial in the tty code, so for this bugfix, I take
the simple approach of using __GFP_NOFAIL and don't worry about memory errors.
This is not a problem because our allocator doesn't fail small allocs as a rule
anyway. So proper error handling is left as an exercise for tty hackers.

[ Arguably filesystem's device inode would ideally be divorced from the
driver's pseudo inode when it is opened, but in practice it's not clear whether
that will ever be worth implementing. ]

Cc: linux-kernel@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

9 years agofs: cleanup files_lock locking
Nick Piggin [Tue, 17 Aug 2010 18:37:35 +0000]
fs: cleanup files_lock locking

fs: cleanup files_lock locking

Lock tty_files with a new spinlock, tty_files_lock; provide helpers to
manipulate the per-sb files list; unexport the files_lock spinlock.

Cc: linux-kernel@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

9 years agofs: remove extra lookup in __lookup_hash
Nick Piggin [Tue, 17 Aug 2010 18:37:34 +0000]
fs: remove extra lookup in __lookup_hash

fs: remove extra lookup in __lookup_hash

Optimize lookup for create operations, where no dentry should often be
common-case. In cases where it is not, such as unlink, the added overhead
is much smaller than the removed.

Also, move comments about __d_lookup racyness to the __d_lookup call site.
d_lookup is intuitive; __d_lookup is what needs commenting. So in that same
vein, add kerneldoc comments to __d_lookup and clean up some of the comments:

- We are interested in how the RCU lookup works here, particularly with
  renames. Make that explicit, and point to the document where it is explained
  in more detail.
- RCU is pretty standard now, and macros make implementations pretty mindless.
  If we want to know about RCU barrier details, we look in RCU code.
- Delete some boring legacy comments because we don't care much about how the
  code used to work, more about the interesting parts of how it works now. So
  comments about lazy LRU may be interesting, but would better be done in the
  LRU or refcount management code.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

9 years agofs: fs_struct rwlock to spinlock
Nick Piggin [Tue, 17 Aug 2010 18:37:33 +0000]
fs: fs_struct rwlock to spinlock

fs: fs_struct rwlock to spinlock

struct fs_struct.lock is an rwlock with the read-side used to protect root and
pwd members while taking references to them. Taking a reference to a path
typically requires just 2 atomic ops, so the critical section is very small.
Parallel read-side operations would have cacheline contention on the lock, the
dentry, and the vfsmount cachelines, so the rwlock is unlikely to ever give a
real parallelism increase.

Replace it with a spinlock to avoid one or two atomic operations in typical
path lookup fastpath.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

9 years agoapparmor: use task path helpers
Nick Piggin [Tue, 17 Aug 2010 18:37:32 +0000]
apparmor: use task path helpers

apparmor: use task path helpers

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

9 years agofs: dentry allocation consolidation
Nick Piggin [Tue, 17 Aug 2010 18:37:31 +0000]
fs: dentry allocation consolidation

fs: dentry allocation consolidation

There are 2 duplicate copies of code in dentry allocation in path lookup.
Consolidate them into a single function.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

9 years agofs: fix do_lookup false negative
Nick Piggin [Tue, 17 Aug 2010 18:37:30 +0000]
fs: fix do_lookup false negative

fs: fix do_lookup false negative

In do_lookup, if we initially find no dentry, we take the directory i_mutex and
re-check the lookup. If we find a dentry there, then we revalidate it if
needed. However if that revalidate asks for the dentry to be invalidated, we
return -ENOENT from do_lookup. What should happen instead is an attempt to
allocate and lookup a new dentry.

This is probably not noticed because it is rare. It is only reached if a
concurrent create races in first (in which case, the dentry probably won't be
invalidated anyway), or if the racy __d_lookup has failed due to a
false-negative (which is very rare).

Fix this by removing code and have it use the normal reval path.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

9 years agopxa3xx: fix ns2cycle equation
Axel Lin [Mon, 16 Aug 2010 08:09:09 +0000]
pxa3xx: fix ns2cycle equation

Test on a PXA310 platform with Samsung K9F2G08X0B NAND flash,
with tCH=5 and clk is 156MHz, ns2cycle(5, 156000000) returns -1.

ns2cycle returns negtive value will break NDTR0_tXX macros.

After checking the commit log, I found the problem is introduced by
commit 5b0d4d7c8a67c5ba3d35e6ceb0c5530cc6846db7
"[MTD] [NAND] pxa3xx: convert from ns to clock ticks more accurately"

To get num of clock cycles, we use below equation:
num of clock cycles = time (ns) / one clock cycle (ns) + 1
We need to add 1 cycle here because integer division will truncate the result.
It is possible the developers set the Min values in SPEC for timing settings.
Thus the truncate may cause problem, and it is safe to add an extra cycle here.

The various fields in NDTR{01} are in units of clock ticks minus one,
thus we should subtract 1 cycle then.

Thus the correct equation should be:
num of clock cycles = time (ns) / one clock cycle (ns) + 1 - 1
                    = time (ns) / one clock cycle (ns)

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Lei Wen <leiwen@marvell.com>
Acked-by: Eric Miao <eric.y.miao@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: stable@kernel.org