Working with ftrace I would get large jumps of 11 millisecs or more with
the clock tracer. This killed the latencing timings of ftrace and also
caused the irqoff self tests to fail.

What was happening is with NO_HZ the idle would stop the jiffy counter and
before the jiffy counter was updated the sched_clock would have a bad
delta jiffies to compare with the gtod with the maximum.

The jiffies would stop and the last sched_tick would record the last gtod.
On wakeup, the sched clock update would compare the gtod + delta jiffies
(which would be zero) and compare it to the TSC. The TSC would have
correctly (with a stable TSC) moved forward several jiffies. But because the
jiffies has not been updated yet the clock would be prevented from moving
forward because it would appear that the TSC jumped too far ahead.

The clock would then virtually stop, until the jiffies are updated. Then
the next sched clock update would see that the clock was very much behind
since the delta jiffies is now correct. This would then jump the clock
forward by several jiffies.

This caused ftrace to report several milliseconds of interrupts off
latency at every resume from NO_HZ idle.

This patch adds hooks into the nohz code to disable the checking of the
maximum clock update when nohz is in effect. It resumes the max check
when nohz has updated the jiffies again.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

With keeping the max and min sched time within one jiffy of the gtod clock
was too tight. Just before a schedule tick the max could easily be hit, as
well as just after a schedule_tick the min could be hit. This caused the
clock to jump around by a jiffy.

This patch widens the minimum to
   last gtod + (delta_jiffies ? delta_jiffies - 1 : 0) * TICK_NSECS

and the maximum to
    last gtod + (2 + delta_jiffies) * TICK_NSECS

This keeps the minum to gtod or if one jiffy less than delta jiffies
and the maxim 2 jiffies ahead of gtod. This may cause unstable TSCs to be
a bit more sporadic, but it helps keep a clock with a stable TSC working well.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

The sched_clock code tries to keep within the gtod time by one tick (jiffy).
The current code mistakenly keeps track of the delta jiffies between
updates of the clock, where the the delta is used to compare with the
number of jiffies that have past since an update of the gtod. The gtod is
updated at each schedule tick not each sched_clock update. After one
jiffy passes the clock is updated fine. But the delta is taken from the
last update so if the next update happens before the next tick the delta
jiffies used will be incorrect.

This patch changes the code to check the delta of jiffies between ticks
and not updates to match the comparison of the updates with the gtod.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

PREEMPT_RCU without HOTPLUG_CPU is broken.  The rcu_online_cpu is called
to initially populate rcu_cpu_online_map with all online CPUs when the
hotplug event handler is installed, and also to populate the map with
CPUs as they come online.  The former case is meant to happen with and
without HOTPLUG_CPU, but without HOTPLUG_CPU, the rcu_offline_cpu
function is no-oped -- while it still gets called, it does not set the
rcu CPU map.

With a blank RCU CPU map, grace periods get to tick by completely
oblivious to active RCU read side critical sections.  This results in
free-before-grace bugs.

Fix is obvious once the problem is known. (Also, change __devinit to
__cpuinit so the function gets thrown away on !HOTPLUG_CPU kernels).
Signed-off-by: Nick Piggin <npiggin@suse.de>
Reported-and-tested-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ Nick is my personal hero of the day - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This is the long awaited ftrace.txt. It explains in quite detail how to
use ftrace and the various tracers.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Daniel Guilak <daniel@danielguilak.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Daniel Guilak <daniel@danielguilak.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: chainiv - Invoke completion function

* 'for-2.6.26' of git://neil.brown.name/md:
  md: ensure all blocks are uptodate or locked when syncing

When chainiv postpones requests it never calls their completion functions.
This causes symptoms such as memory leaks when IPsec is in use.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Remove the dubious attempt to prefer 'compute' over 'read'.  Not only is it
wrong given commit c337869d (md: do not compute parity unless it is on a failed
drive), but it can trigger a BUG_ON in handle_parity_checks5().

Cc: <stable@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Neil Brown <neilb@suse.de>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
  RDMA/cxgb3: Fix regression caused by class_device -> device conversion

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2:
  [PATCH] ocfs2/dlm: Fixes oops in dlm_new_lockres()

There is dma_mask in of_device upon of_platform_device_create()
but we don't actually set coherent_dma_mask. This may cause weird
behavior of USB subsystem using of_device USB host drivers.
Signed-off-by: Vitaly Bordug <vitb@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: tcrypt - Fix memory leak in test_cipher

Signed-off-by: Daniel Guilak <daniel@danielguilak.com>
Acked-by: Josh Triplett <josh@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The change to iwch_provider.c in commit f4e91eb4 ("IB: convert struct
class_device to struct device") undid the fix done in commit 7f049f2f
("RDMA/cxgb3: Hold rtnl_lock() around ethtool get_drvinfo call").  It
removed the calls to rtnl_lock() that serialized the iw_cxgb3 ethtool
ops calls into the cxgb3 driver.  This locking is needed to avoid
messing up the internal state of the cxgb3 driver.
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

On 2.6.26-rc9, the commit 05946bce
("fsl_diu_fb: fix build with CONFIG_PM=y, plus fix some warnings")
breaks its previous fix f969c567
("fsl-diu-db: compile fix")

This patch reverts the broken part.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'hotfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
  SUNRPC: Fix an rpcbind breakage for the case of IPv6 lookups
  SUNRPC: Fix a double-free in rpcbind
  NFS: Fix readdir cache invalidation

* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
  [MIPS] Fix 32bit kernels on R4k with 128 byte cache line size
  [MIPS] Atlas, decstation: Fix section mismatches triggered by defconfigs

With the removal of struct file from the xattr code,
reiserfs_file_release() isn't used anymore, so the prealloc isn't
discarded.  This causes hangs later down the line.

This patch adds it to reiserfs_delete_inode.  In most cases it will be a
no-op due to it already having been called, but will avoid hangs with
xattrs.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Now that rpcb_next_version has been split into an IPv4 version and an IPv6
version, we Oops when rpcb_call_async attempts to look up the IPv6-specific
RPC procedure in rpcb_next_version.

Fix the Oops simply by having rpcb_getport_async pass the correct RPC
procedure as an argument.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

It is wrong to be freeing up the rpcbind arguments if the call to
rpcb_call_async() fails, since they should already have been freed up by
rpcb_map_release().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

invalidate_inode_pages2_range() takes page offset arguments, not byte
ranges.

Another thought is that individual pages might perhaps get evicted by VM
pressure, in which case we might perhaps want to re-read not only the
evicted page, but all subsequent pages too (in case the server returns
more/less data per page so that the alignment of the next entry
changes). We should therefore remove the condition that we only do this on
page->index==0.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

The generated copy_page for R4k CPU with a 128 byte cache line size used
Create Dirty Exclusive cache line operations even if only part of the
cache line was filled.  This change avoids generating cache operations,
if only part of the cache line size is copied in one loop. It also
increases the maxmimum loop size, because the generated code even fits
into the available space for r4k CPUs with 128 byte cache line size.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Resolve these mismatches by defining affected functions with the __cpuinit
attribute, rather than __init.
Signed-off-by: Shane McDonald <mcdonald.shane@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6:
  it8213: fix return value in it8213_init_one()
  palm_bk3710: fix IDECLK period calculation
  ide: add __ide_default_irq() inline helper

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

The driver uses completely bogus rounding formula for calculating period from
the IDECLK frequency which gives one-off period values (e.g. 11 ns with 100 MHz
IDECLK) which in turn can lead to overclocked IDE transfer timings.  Actually,
rounding is just wrong in this case, so use a mere division for a safe result.

While at it, also:

- give 'ide_palm_clk' variable a more suitable name;

- get rid of the useless 'ideclkp' variable;

- drop the LISP stype 'p' postfix from the 'clkp' variable's name. :-)
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: mcherkashin@ru.mvista.com
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Add __ide_default_irq() inline helper and use it instead of
ide_default_irq() in ide-probe.c and ns87415.c (all host drivers
except IDE PCI ones always setup hwif->irq so it is enough to
check only for I/O bases 0x1f0 and 0x170).

This fixes post-2.6.25 regression since ide_default_irq()
define could shadow ide_default_irq() inline.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6:
  [S390] protect _PAGE_SPECIAL bit against mprotect

As Andy Whitcroft recently pointed out, the current powerpc version of
huge_ptep_set_wrprotect() has a bug.  It just calls ptep_set_wrprotect()
which in turn calls pte_update() then hpte_need_flush() with the 'huge'
argument set to 0.  This will cause hpte_need_flush() to flush the wrong
hash entries (of any).  Andy's fix for this is already in the powerpc
tree as commit 016b33c4.

I have confirmed this is a real bug, not masked by some other
synchronization, with a new testcase for libhugetlbfs.  A process write
a (MAP_PRIVATE) hugepage mapping, fork(), then alter the mapping and
have the child incorrectly see the second write.

Therefore, this should be fixed for 2.6.26, and for the stable tree.
Here is a suitable patch for 2.6.26, which I think will also be suitable
for the stable tree (neither of the headers in question has been changed
much recently).

It is cut down slighlty from Andy's original version, in that it does
not include a 32-bit version of huge_ptep_set_wrprotect().  Currently,
hugepages are not supported on any 32-bit powerpc platform.  When they
are, a suitable 32-bit version can be added - the only 32-bit hardware
which supports hugepages does not use the conventional hashtable MMU and
so will have different needs anyway.
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Stop mprotect's pte_modify from wiping out the s390 pte_special bit, which
caused oops thereafter when vm_normal_page thought X's abnormal was normal.
Debugged-by: Ryan Hope <rmh3093@gmail.com>
Debugged-by: Zan Lynx <zlynx@acm.org>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Coverity CID: 2306 & 2307 RESOURCE_LEAK

In the second for loop in test_cipher(), data is allocated space with
kzalloc() and is only ever freed in an error case.
Looking at this loop, data is written to this memory but nothing seems
to read from it. 
So here is a patch removing the allocation, I think this is the right
fix.

Only compile tested.
Signed-off-by: Darren Jenkins <darrenrjenkins@gmailcom>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
  Revert "PCI: Correct last two HP entries in the bfsort whitelist"

This reverts commit a1676072.  It duplicates
the change from 8d64c781 and only one should be
applied, otherwise some of the Dell quirks are lost.

Thanks to Tony Camuso for catching this.
Acked-by: Tony Camuso <tcamuso@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Patch fixes a race that can result in an oops while adding a
lockres to the dlm lockres tracking list.

Bug introduced by mainline commit 29576f8b.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

There are various constraints on the use of unit-at-a-time:
 - i386 uses no-unit-at-a-time for pre-4.0 (not 4.3)
 - x86_64 uses unit-at-a-time always

Uli reported a crash on x86_64 with gcc 4.1.2 with unit-at-a-time,
resulting in commit c0a18111

Ingo reported a gcc internal error with gcc 4.3 with no-unit-at-a-timem,
resulting in 22eecde2

Benny Halevy is seeing extern inlines not resolved with gcc 4.3 with
no-unit-at-a-time

This patch reintroduces unit-at-a-time for gcc >= 4.0, bringing back the
possibility of Uli's crash.  If that happens, we'll debug it.

I started seeing both the internal compiler errors and unresolved
inlines on Fedora 9.  This patch fixes both problems, without so far
reintroducing the crash reported by Uli.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Benny Halevy <bhalevy@panasas.com>
Cc: Adrian Bunk <bunk@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
  can: add sanity checks
  fs_enet: restore promiscuous and multicast settings in restart()
  ibm_newemac: Fixes entry of short packets
  ibm_newemac: Fixes kernel crashes when speed of cable connected changes
  pasemi_mac: Access iph->tot_len with correct endianness
  ehea: Access iph->tot_len with correct endianness
  ehea: fix race condition
  ehea: add MODULE_DEVICE_TABLE
  ehea: fix might sleep problem
  forcedeth: fix lockdep warning on ethtool -s
  Add missing skb->dev assignment in Frame Relay RX code
  bridge: fix use-after-free in br_cleanup_bridges()
  tcp: fix a size_t < 0 comparison in tcp_read_sock
  tcp: net/ipv4/tcp.c needs linux/scatterlist.h
  libertas: support USB persistence on suspend/resume (resend)
  iwlwifi: drop skb silently for Tx request in monitor mode
  iwlwifi: fix incorrect 5GHz rates reported in monitor mode

A recent patch to legacy_serial.c factored out some code by
using the of_match_node() facility to match a node against
an array of possible matches. However, the patch didn't properly
terminate the array causing potential crashes in cases where no
match is found. In addition, the name of the array was poorly
chosen for a static symbol making debugging harder.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>