Add comments to the logic that infers quiescent states when interrupting
from either user mode or the idle loop. Also add a memory barrier: it
appears that James Huang was in fact onto something, as the scheduler
is much less synchronization happy than it once was, so we can no longer
rely on its memory barriers in all cases.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reported-by: James Huang <jamesclhuang@yahoo.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Fourth cut of patch to provide the call_rcu_sched(). This is again to
synchronize_sched() as call_rcu() is to synchronize_rcu().
Should be fine for experimental and -rt use, but not ready for inclusion.
With some luck, I will be able to tell Andrew to come out of hiding on
the next round.
Passes multi-day rcutorture sessions with concurrent CPU hotplugging.
Fixes since the first version include a bug that could result in
indefinite blocking (spotted by Gautham Shenoy), better resiliency
against CPU-hotplug operations, and other minor fixes.
Fixes since the second version include reworking grace-period detection
to avoid deadlocks that could happen when running concurrently with
CPU hotplug, adding Mathieu's fix to avoid the softlockup messages,
as well as Mathieu's fix to allow use earlier in boot.
Fixes since the third version include a wrong-CPU bug spotted by
Andrew, getting rid of the obsolete synchronize_kernel API that somehow
snuck back in, merging spin_unlock() and local_irq_restore() in a
few places, commenting the code that checks for quiescent states based
on interrupting from user-mode execution or the idle loop, removing
some inline attributes, and some code-style changes.
Known/suspected shortcomings:
o I still do not entirely trust the sleep/wakeup logic. Next step
will be to use a private snapshot of the CPU online mask in
rcu_sched_grace_period() -- if the CPU wasn't there at the start
of the grace period, we don't need to hear from it. And the
bit about accounting for changes in online CPUs inside of
rcu_sched_grace_period() is ugly anyway.
o It might be good for rcu_sched_grace_period() to invoke
resched_cpu() when a given CPU wasn't responding quickly,
but resched_cpu() is declared static...
This patch also fixes a long-standing bug in the earlier preemptable-RCU
implementation of synchronize_rcu() that could result in loss of
concurrent external changes to a task's CPU affinity mask. I still cannot
remember who reported this...
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
rcu_batches_completed and rcu_patches_completed_bh are both declared
in rcuclassic.h and rcupreempt.h. This patch removes the extra
prototypes for them from rcupdate.h.
rcu_batches_completed_bh is defined as a static inline in the rcupreempt.h
header file. Trying to export this as EXPORT_SYMBOL_GPL causes linking problems
with the powerpc linker. There's no need to export a static inlined function.
Modules must be compiled with the same type of RCU implementation as the
kernel they are for.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'i2c-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6:
i2c/max6875: Really prevent 24RF08 corruption
i2c-amd756: Fix functionality flags
i2c: Kill the old driver matching scheme
i2c: Convert remaining new-style drivers to use module aliasing
i2c: Switch pasemi to the new device/driver matching scheme
i2c: Clean up Blackfin BF527 I2C device declarations
i2c-nforce2: Disable the second SMBus channel on the DFI Lanparty NF4 Expert
i2c: New co-maintainer
Add multi_defconfig, to build a kernel for all supported m68k platforms,
excluding Sun 3 (Sun 3 kernels are incompatible with all other m68k platforms)
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The *_ISA type defines are quite generic and cause namespace conflicts
(e.g. with `AMIGAHW_DECLARE(GG2_ISA)' in <asm/amigahw.h>) for some kernel
configurations. Use ISA_TYPE_* to avoid such conflicts.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mark Q40/Q60 floppy support broken:
arch/m68k/q40/q40ints.c: In function 'q40_irq_handler':
arch/m68k/q40/q40ints.c:214: error: implicit declaration of function 'floppy_hardint'
Including <asm/floppy.h> doesn't help, as it causes a lot of additional error
messages (cfr. Sun 3x).
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
According to the tests in do_initcalls(), the proper error code in case no
device is found is -ENODEV, not -ENXIO or -EIO.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some input drivers do not check whether they're actually running on the
correct platform, causing multi-platform kernels to crash if they are not.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some network drivers do not check whether they're actually running on the
correct platform, causing multi-platform kernels to crash if they are not.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The Apollo frame buffer device driver (dnfb) doesn't check whether it's
actually running on Apollo hardware, causing a crash if it isn't.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The Macintosh IDE driver (macide) doesn't check whether it's actually running
on Mac hardware, causing a crash if it isn't.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When running a HP300-enabled kernel on non-HP300 hardware, a test in the early
startup code jumps to the wrong label, causing a double bus fault.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use `__builtin_trap()' instead of `asm volatile("illegal")' in the m68k BUG()
macros (as suggested by Andrew Pinski), to kill warnings in code that assumes
BUG() does not return.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The Hisoft Whippet PCMCIA serial driver has been removed a long time ago, but
it's Kconfig symbol still existed.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Correct FB_HP300 dependencies:
- FB_HP300 doesn't depend only on HP300, but also on DIO (which depends on
HP300)
- FB_HP300 does not need FB_CFB_FILLRECT
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CONFIG_FB_DAFB is a leftover from pre-Kconfig
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Convert access_ok() from a macro to an inline function, so the compiler no
longer complains about unused variables:
fs/read_write.c: In function 'rw_copy_check_uvector':
fs/read_write.c:556: warning: unused variable 'buf'
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
i2c-core takes care of the possible corruption of 24RF08 chips for
quite some times, so device devices no longer need to do it. And they
really should not, as applying the prevention twice voids it.
I thought that I had fixed all drivers long ago but apparently I had
missed that one.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Ben Gardner <bgardner@wabtec.com>
The i2c-amd756 driver pretends to support SMBus process call
transactions but actually does not. Fix it.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Remove the old driver_name/type scheme for i2c driver matching. Only the
standard aliasing model will be used from now on.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Update all the remaining new-style i2c drivers to use standard module
aliasing instead of the old driver_name/type driver matching scheme.
Note that the tuner driver is a bit quirky at the moment, as it
overwrites i2c_client.name with arbitrary strings. We write "tuner"
back on remove, to make sure that driver cycling will work properly,
but there may still be troublesome corner cases.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The old device/driver matching scheme is going away so stop using it.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Olof Johansson <olof@lixom.net>
I2C_BOARD_INFO() now sets the type field so no need to set it
separatetly.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Bryan Wu <cooloney@kernel.org>
There is a strange chip at 0x2e on the second SMBus channel of the
DFI Lanparty NF4 Expert motherboard. Accessing the chip reboots the
system. As there's nothing interesting on this SMBus channel, the
easiest and safest thing to do is to disable it on that board.
This is a better fix to bug #5889 than the it87 driver update that was
done originally:
http://bugzilla.kernel.org/show_bug.cgi?id=5889
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Ben Dooks agreed to become my co-maintainer for the i2c subsystem. In
particular, Ben will help with drivers for embedded systems, of which
my experience is inexistent. Thanks Ben and welcome on board!
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Ben Dooks <ben-linux@fluff.org>
If cpufreq is enabled, pxafb wants to call the removed
get_clk_frequency_khz() function for a debug printk. Remove
this reference.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Parenthesis fix in include/asm-arm/arch-omap/control.h
Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Two changes are necessary to enable proper operation of the DM9000 device with
the Colibri PXA 270 board: firstly, the IRQ type needs to be configured for
rising edge interrupts, and secondly this configuration needs to be
communicated through to the DM9000.
[akpm@linux-foundation.org: remove set_irq_type() call as per ben-linux request]
Signed-off-by: Michael Abbott <michael.abbott@diamond.ac.uk>
Cc: Daniel Mack <daniel@caiaq.org>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch adds the missing MODULE_LICENSE("GPL").
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Whereas most Orion 5x machine support code would initialise the PCI
subsystem with nr_controllers in their struct hw_pci set to 2, the
DNS323 and Kurobox Pro machine support code had nr_controllers set
to 1.
This was presumably done because on those two machines, the PCI(-X)
controller (nr == 1) isn't used, requiring initialisation of only
the PCIe controller (nr == 0.) However, not initialising the PCI(-X)
controller on boards that don't use it leads to a situation where
both the PCIe and the PCI(-X) controller think that their root bus is
zero, and it messes up IRQ assignment.
This patch changes the DNS323 and Kurobox Pro support code to always
use nr_controllers == 2.
Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The CPU's dma_flush_range() operation needs to clean+invalidate the
given memory area if the cache is in writeback mode, or do just the
invalidate part if the cache is in writethrough mode, but the current
proc-arm{925,926,940,946} (incorrectly) do a cache clean in the
latter case. This patch fixes that.
Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Martin Michlmayr reported that fuse complains:
ERROR: "copy_page" [fs/fuse/fuse.ko] undefined!
so export the needed function.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
irqs.h:
* rename IRQ_LOCOMO_SPI_OVRN to IRQ_LOCOMO_SPI_REND
locomo.h:
* add some definition for locomo spi controller
* correct some errors
locomo.c:
* correct some errors
* add set_type for locomo gpio irq chip
Signed-off-by: Thomas Kunze <thommycheck@gmx.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: disable mwait for AMD family 10H/11H CPUs
x86: fix crash on cpu hotplug on pat-incapable machines
x86: remove mwait capability C-state check
The previous revert of 0c07ee38c9 left
out the mwait disable condition for AMD family 10H/11H CPUs.
Andreas Herrman said:
It depends on the CPU. For AMD CPUs that support MWAIT this is wrong.
Family 0x10 and 0x11 CPUs will enter C1 on HLT. Powersavings then
depend on a clock divisor and current Pstate of the core.
If all cores of a processor are in halt state (C1) the processor can
enter the C1E (C1 enhanced) state. If mwait is used this will never
happen.
Thus HLT saves more power than MWAIT here.
It might be best to switch off the mwait flag for these AMD CPU
families like it was introduced with commit
f039b75471 (x86: Don't use MWAIT on AMD
Family 10)
Re-add the AMD families 10H/11H check and disable the mwait usage for
those.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
pat_disable() is __init, which means it goes away after booting is complete.
Unfortunately it is used by the hotplug code if the machine is not
pat-capable, causing a crash.
Fix by marking pat_disable() as __cpuinit.
Signed-off-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Vegard Nossum reports:
| powertop shows between 200-400 wakeups/second with the description
| "<kernel IPI>: Rescheduling interrupts" when all processors have load (e.g.
| I need to run two busy-loops on my 2-CPU system for this to show up).
|
| The bisect resulted in this commit:
|
| commit 0c07ee38c9
| Date: Wed Jan 30 13:33:16 2008 +0100
|
| x86: use the correct cpuid method to detect MWAIT support for C states
remove the functional effects of this patch and make mwait unconditional.
A future patch will turn off mwait on specific CPUs where that causes
power to be wasted.
Bisected-by: Vegard Nossum <vegard.nossum@gmail.com>
Tested-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This fixes the missing ram regression reported by
Mikael Pettersson <mikpe@it.uu.se>, much thanks for
all of this help in diagnosing this.
The second argument to lmb_reserve() is a size,
not an end address bounds.
Tested-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: David S. Miller <davem@davemloft.net>
