The clear_buddies function does not seem to play well with the concept
of hierarchical runqueues.  In the following tree, task groups are
represented by 'G', tasks by 'T', next by 'n' and last by 'l'.

     (nl)
    /    \
   G(nl)  G
   / \     \
 T(l) T(n)  T

This situation can arise when a task is woken up T(n), and the previously
running task T(l) is marked last.

When clear_buddies is called from either T(l) or T(n), the next and last
buddies of the group G(nl) will be cleared.  This is not the desired
result, since we would like to be able to find the other type of buddy
in many cases.

This especially a worry when implementing yield_task_fair through the
buddy system.

The fix is simple: only clear the buddy type that the task itself
is indicated to be.  As an added bonus, we stop walking up the tree
when the buddy has already been cleared or pointed elsewhere.
Signed-off-by: NRik van Riel <riel@redhat.coM>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110201094837.6b0962a9@annuminas.surriel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

With CONFIG_FAIR_GROUP_SCHED, each task_group has its own cfs_rq.
Yielding to a task from another cfs_rq may be worthwhile, since
a process calling yield typically cannot use the CPU right now.

Therefor, we want to check the per-cpu nr_running, not the
cgroup local one.
Signed-off-by: NRik van Riel <riel@redhat.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110201094715.798c4f86@annuminas.surriel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Fix the build on UP.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Turner <pjt@google.com>
LKML-Reference: <20110122044852.102126037@google.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

When a task is taken out of the fair class we must ensure the vruntime
is properly normalized because when we put it back in it will assume
to be normalized.

The case that goes wrong is when changing away from the fair class
while sleeping. Sleeping tasks have non-normalized vruntime in order
to make sleeper-fairness work. So treat the switch away from fair as a
wakeup and preserve the relative vruntime.

Also update sysrq-n to call the ->switch_{to,from} methods.
Reported-by: NOnkalo Samu <samu.p.onkalo@nokia.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Since commit 48c5ccae (sched: Simplify cpu-hot-unplug task
migration) this should no longer happen, so remove the code.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

softirq time in ksoftirqd context is not accounted in ns granularity
per cpu softirq stats, as we want that to be a part of ksoftirqd
exec_runtime.

Accounting them as softirq on /proc/stat separately.
Tested-by: NShaun Ruffell <sruffell@digium.com>
Signed-off-by: NVenkatesh Pallipadi <venki@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1292980144-28796-6-git-send-email-venki@google.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

CONFIG_IRQ_TIME_ACCOUNTING adds ns granularity irq time on each CPU.
This info is already used in scheduler to do proper task chargeback
(earlier patches). This patch retro-fits this ns granularity
hardirq and softirq information to /proc/stat irq and softirq fields.

The update is still done on timer tick, where we look at accumulated
ns hardirq/softirq time and account the tick to user/system/irq/hardirq/guest
accordingly.

No new interface added.

Earlier versions looked at adding this as new fields in some /proc
files. This one seems to be the best in terms of impact to existing
apps, even though it has somewhat more kernel code than earlier versions.
Tested-by: NShaun Ruffell <sruffell@digium.com>
Signed-off-by: NVenkatesh Pallipadi <venki@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1292980144-28796-5-git-send-email-venki@google.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Refactor account_system_time, to separate out the logic of
identifying the update needed and code that does actual update.

This is used by following patch for IRQ_TIME_ACCOUNTING,
which has different identification logic and same update logic.
Tested-by: NShaun Ruffell <sruffell@digium.com>
Signed-off-by: NVenkatesh Pallipadi <venki@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1292980144-28796-4-git-send-email-venki@google.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Add nsecs_to_cputime64 interface. This is used in following patches that
updates cpu irq stat based on ns granularity info in IRQ_TIME_ACCOUNTING.
Tested-by: NShaun Ruffell <sruffell@digium.com>
Signed-off-by: NVenkatesh Pallipadi <venki@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1292980144-28796-3-git-send-email-venki@google.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Cleanup patch, freeing up PF_KSOFTIRQD and use per_cpu ksoftirqd pointer
instead, as suggested by Eric Dumazet.
Tested-by: NShaun Ruffell <sruffell@digium.com>
Signed-off-by: NVenkatesh Pallipadi <venki@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1292980144-28796-2-git-send-email-venki@google.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Since cfs->{load_stamp,load_last} are zero-initalized the initial load update
will consider the delta to be 'since the beginning of time'.

This results in a lot of pointless divisions to bring this large period to be
within the sysctl_sched_shares_window.

Fix this by initializing load_stamp to be 1 at cfs_rq initialization, this
allows for an initial load_stamp > load_last which then lets standard idle
truncation proceed.

We avoid spinning (and slightly improve consistency) by fixing delta to be
[period - 1] in this path resulting in a slightly more predictable shares ramp.
(Previously the amount of idle time preserved by the overflow would range between
[period/2,period-1].)
Signed-off-by: NPaul Turner <pjt@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110122044852.102126037@google.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Re-visiting this: Since update_cfs_shares will now only ever re-weight an
entity that is a relative parent of the current entity in enqueue_entity; we
can safely issue the account_entity_enqueue relative to that cfs_rq and avoid
the requirement for special handling of the enqueue case in update_cfs_shares.
Signed-off-by: NPaul Turner <pjt@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110122044851.915214637@google.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The delta in clock_task is a more fair attribution of how much time a tg has
been contributing load to the current cpu.

While not really important it also means we're more in sync (by magnitude)
with respect to periodic updates (since __update_curr deltas are clock_task
based).
Signed-off-by: NPaul Turner <pjt@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110122044852.007092349@google.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Since updates are against an entity's queuing cfs_rq it's not possible to
enter update_cfs_{shares,load} with a NULL cfs_rq.  (Indeed, update_cfs_load
would crash prior to the check if we did anyway since we load is examined
during the initializers).

Also, in the update_cfs_load case there's no point
in maintaining averages for rq->cfs_rq since we don't perform shares
distribution at that level -- NULL check is replaced accordingly.

Thanks to Dan Carpenter for pointing out the deference before NULL check.
Signed-off-by: NPaul Turner <pjt@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110122044851.825284940@google.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

While care is taken around the zero-point in effective_load to not exceed
the instantaneous rq->weight, it's still possible (e.g. using wake_idx != 0)
for (load + effective_load) to underflow.

In this case the comparing the unsigned values can result in incorrect balanced
decisions.
Signed-off-by: NPaul Turner <pjt@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110122044851.734245014@google.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

* 'fixes' of master.kernel.org:/home/rmk/linux-2.6-arm:
  ALSA: AACI: fix timeout duration
  ALSA: AACI: fix timeout condition checking
  ARM: 6636/1: ep93xx: default multiplexed gpio ports to gpio mode
  ARM: 6637/1: Make the argument to virt_to_phys() "const volatile"
  ARM: twd: ensure timer reload is reprogrammed on entry to periodic mode
  ARM: 6635/2: Configure reference clock for Versatile Express timers
  ARM: versatile: name configuration options after actual board names
  ARM: realview: name configuration options after actual board names
  ARM: realview,vexpress: fix section mismatch warning for pen_release
  ARM: 6632/3: mmci: stop using the blockend interrupts

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2:
  nilfs2: fix crash after one superblock became unavailable

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
  m68k/amiga: Fix "debug=mem"
  m68k/atari: Rename "scc" to "atari_scc"
  m68k: Uninline strchr()

Merge branch 'rmobile-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6

* 'rmobile-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
  ARM: mach-shmobile: AG5EVM LCDC / MIPI-DSI platform data
  ARM: mach-shmobile: sh73a0 CPGA fix for PLL CFG bit
  ARM: mach-shmobile: mackerel: clarify shdi/mmcif switch settings
  ARM: mach-shmobile: sh73a0 CPGA fix for IrDA MSTP
  ARM: mach-shmobile: sh73a0 CPGA fix for FRQCRA M3
  ARM: mach-shmobile: remove sh7367 on-chip set_irq_type()
  ARM: mach-shmobile: sh7372 INTCS MFIS2 interrupt update
  ARM: mach-shmobile: ag5evm: Add IrDA support
  ARM: mach-shmobile: clock-sh7372: fixup pllc2 set_rate
  mmc: sh_mmcif: Convert to __raw_xxx() I/O accessors.
  ARM: mach-shmobile: ag5evm requires GPIOLIB
  ARM: mach-shmobile: fix cpu_base of gic_init() on sh73a0

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

* 'fbdev-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/fbdev-2.6:
  mailmap: Add an entry for Axel Lin.
  video: fix some comments in drivers/video/console/vgacon.c
  drivers/video/bf537-lq035.c: Add missing IS_ERR test
  video: pxa168fb: remove a redundant pxa168fb_check_var call
  video: da8xx-fb: fix fb_probe error path
  video: pxa3xx-gcu: Return -EFAULT when copy_from_user() fails
  video: nuc900fb: properly free resources in nuc900fb_remove
  video: nuc900fb: fix compile error

* 'sh-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
  sh: Fix build of sh7750 base boards
  sh: update INTC to clear IRQ sense valid flag
  sh: Fix sh build failure when CONFIG_SFC=m
  sh: fix MSIOF0 SPI on ecovec: it conflicts with VOU
  sh: support XZ-compressed kernel.
  sh: Fix up breakage from asm-generic/pgtable.h changes.

Fix __key_link_end()'s attempt to fix up the quota if an error occurs.

There are two erroneous cases: Firstly, we always decrease the quota if
the preallocated replacement keyring needs cleaning up, irrespective of
whether or not we should (we may have replaced a pointer rather than
adding another pointer).

Secondly, we never clean up the quota if we added a pointer without the
keyring storage being extended (we allocate multiple pointers at a time,
even if we're not going to use them all immediately).

We handle this by setting the bottom bit of the preallocation pointer in
__key_link_begin() to indicate that the quota needs fixing up, which is
then passed to __key_link() (which clears the whole thing) and
__key_link_end().
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

GPL V2 should be GPL v2
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A B C D E ...
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

busy_loop() returns negative error code, thus change err variable
from u32 to int to properly propagate correct error code.

Also remove unneeded initialization for err and i variables.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Relying on the access time of peripherals is unreliable - it depends
on the speed of the CPU and the bus.  On Versatile Express, these
timeouts were expiring, causing the driver to fail.

Add udelay(1) to ensure that they don't expire early, and adjust
timeouts to give a reasonable margin over the response times.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Ensure that a timeout coincident with the condition being waited for
results in success rather than failure.  This helps avoid timeout
conditions being inappropriately flagged.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The EP93xx C and D GPIO ports are multiplexed with the Keypad Interface
peripheral.  At power-up they default into non-GPIO mode with the Key
Matrix controller enabled so these ports are unusable for GPIO.  Note
that the Keypad Interface peripheral is only available in the EP9307,
EP9312, and EP9315 processor variants.

The keypad support will clear the DeviceConfig bits appropriately to
enable the Keypad Interface when the driver is loaded.  And, when the
driver is unloaded it will set the bits to return the ports to GPIO mode.

To make these ports available for GPIO after power-up on all EP93xx
processor variants, set the KEYS and GONK bits in the DeviceConfig
register.

Similarly, the E, G, and H ports are multiplexed with the IDE Interface
peripheral.  At power-up these also default into non-GPIO mode.  Note
that the IDE peripheral is only available in the EP9312 and EP9315
processor variants.

Since an IDE driver is not even available in mainline, set the EONIDE,
GONIDE, and HONIDE bits in the DeviceConfig register so that these
ports will be available for GPIO use after power-up.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: NRyan Mallon <ryan@bluewatersys.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Changing the virt_to_phys() argument to "const volatile void *" avoids
compiler warnings in some situations where this function is used.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NStephen Boyd <sboyd@codeaurora.org>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Ensure that the twd timer reload value is reprogrammed each time we
enter periodic mode.  This ensures that the reload value is always
reset correctly.
Tested-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NColin Cross <ccross@android.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Timers on Versatile Express mainboard are used as system clock/event
sources. Driver assumes that they are clocked with 1MHz signal.
Old V2M firmware apparently configured it by default, but on newer
boards one can observe that "sleep 1" command takes over 30 seconds
to finish, as the timers are fed with 32kHz instead...

This patch performs required magic and also removes code clearing
timer's control registers, as exactly the same operations are
performed by the timer driver few jiffies later.
Signed-off-by: NPawel Moll <pawel.moll@arm.com>
Tested-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Update the option text to those which appear on the front of the
appropriate board user guides.  This gives consistent board naming, and
makes it obvious which option is for which platform.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

As no one seems to really know which configuration options tie up with
which boards, I thought I'd do some investigation and try to work it
out.  After discussion with some folk in linaro, I think I have this
nailed.

The names are updated to use the name on the front of the appropriate
board user guide for the various baseboards, which I've taken to be
the official name for each board.

I haven't significantly updated the descriptions for the tiles as that
is even less clear - as far as I can see on ARMs website, there is no
Cortex-A9 tile for Realview EB - only ARM11MPCore, ARM1156T2F-S,
ARM1176TZF-S and Cortex-R4F.  So exactly what this 'Multicore Cortex-A9
Tile' is...
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Fix two section mismatch warnings in the platform SMP bringup code for
Realview and Versatile Express:

WARNING: arch/arm/mach-realview/built-in.o(.text+0x8ac): Section mismatch in reference from the function write_pen_release() to the variable .cpuinit.data:pen_release
The function write_pen_release() references
the variable __cpuinitdata pen_release.
This is often because write_pen_release lacks a __cpuinitdata
annotation or the annotation of pen_release is wrong.

WARNING: arch/arm/mach-vexpress/built-in.o(.text+0x7b4): Section mismatch in reference from the function write_pen_release() to the variable .cpuinit.data:pen_release
The function write_pen_release() references
the variable __cpuinitdata pen_release.
This is often because write_pen_release lacks a __cpuinitdata
annotation or the annotation of pen_release is wrong.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Not all of Axel's patches have used a consistent casing, so fix it up
here.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Now vgacon_scrollback_startup() uses slab, not bootmem,
the comment above it is obsolete, so does __init_refok.
Signed-off-by: NWANG Cong <amwang@redhat.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

lcd_device_register may return ERR_PTR, so a check is added for this value
before the dereference.  All of the other changes reorganize the error
handling code in this function to avoid duplicating all of it in the added
case.

In the original code, in one case, the global variable fb_buffer was set to
NULL in error code that appears after this variable is initialized.  This
is done now in all error handling code that has this property.

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

// <smpl>
@r@
identifier f;
@@
f(...) { ... return ERR_PTR(...); }

@@
identifier r.f, fld;
expression x;
statement S1,S2;
@@
 x = f(...)
 ... when != IS_ERR(x)
(
 if (IS_ERR(x) ||...) S1 else S2
|
*x->fld
)
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Acked-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Current implementation calls pxa168fb_check_var twice in pxa168fb_probe.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Current implementation puts CONFIG_CPU_FREQ at wrong place, CONFIG_CPU_FREQ
is for lcd_da8xx_cpufreq_deregister not for unregister_framebuffer.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>