Make some changes to the NEED_RESCHED and POLLING_NRFLAG to reduce
confusion, and make their semantics rigid. Improves efficiency of
resched_task and some cpu_idle routines.
* In resched_task:
- TIF_NEED_RESCHED is only cleared with the task's runqueue lock held,
and as we hold it during resched_task, then there is no need for an
atomic test and set there. The only other time this should be set is
when the task's quantum expires, in the timer interrupt - this is
protected against because the rq lock is irq-safe.
- If TIF_NEED_RESCHED is set, then we don't need to do anything. It
won't get unset until the task get's schedule()d off.
- If we are running on the same CPU as the task we resched, then set
TIF_NEED_RESCHED and no further action is required.
- If we are running on another CPU, and TIF_POLLING_NRFLAG is *not* set
after TIF_NEED_RESCHED has been set, then we need to send an IPI.
Using these rules, we are able to remove the test and set operation in
resched_task, and make clear the previously vague semantics of
POLLING_NRFLAG.
* In idle routines:
- Enter cpu_idle with preempt disabled. When the need_resched() condition
becomes true, explicitly call schedule(). This makes things a bit clearer
(IMO), but haven't updated all architectures yet.
- Many do a test and clear of TIF_NEED_RESCHED for some reason. According
to the resched_task rules, this isn't needed (and actually breaks the
assumption that TIF_NEED_RESCHED is only cleared with the runqueue lock
held). So remove that. Generally one less locked memory op when switching
to the idle thread.
- Many idle routines clear TIF_POLLING_NRFLAG, and only set it in the inner
most polling idle loops. The above resched_task semantics allow it to be
set until before the last time need_resched() is checked before going into
a halt requiring interrupt wakeup.
Many idle routines simply never enter such a halt, and so POLLING_NRFLAG
can be always left set, completely eliminating resched IPIs when rescheduling
the idle task.
POLLING_NRFLAG width can be increased, to reduce the chance of resched IPIs.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Con Kolivas <kernel@kolivas.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Run idle threads with preempt disabled.
Also corrected a bugs in arm26's cpu_idle (make it actually call schedule()).
How did it ever work before?
Might fix the CPU hotplugging hang which Nigel Cunningham noted.
We think the bug hits if the idle thread is preempted after checking
need_resched() and before going to sleep, then the CPU offlined.
After calling stop_machine_run, the CPU eventually returns from preemption and
into the idle thread and goes to sleep. The CPU will continue executing
previous idle and have no chance to call play_dead.
By disabling preemption until we are ready to explicitly schedule, this bug is
fixed and the idle threads generally become more robust.
From: alexs <ashepard@u.washington.edu>
PPC build fix
From: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
MIPS build fix
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Some architectures define and use this type in their compat_ioctl code, but
all of them can easily use the identical ioctl_trans_handler_t type that is
defined in common code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch removes almost all inclusions of linux/version.h. The 3
#defines are unused in most of the touched files.
A few drivers use the simple KERNEL_VERSION(a,b,c) macro, which is
unfortunatly in linux/version.h.
There are also lots of #ifdef for long obsolete kernels, this was not
touched. In a few places, the linux/version.h include was move to where
the LINUX_VERSION_CODE was used.
quilt vi `find * -type f -name "*.[ch]"|xargs grep -El '(UTS_RELEASE|LINUX_VERSION_CODE|KERNEL_VERSION|linux/version.h)'|grep -Ev '(/(boot|coda|drm)/|~$)'`
search pattern:
/UTS_RELEASE\|LINUX_VERSION_CODE\|KERNEL_VERSION\|linux\/\(utsname\|version\).h
Signed-off-by: Olaf Hering <olh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
MPC834x uses the gianfar network driver which now uses the new phylib. We
need to update the platform code to create a gianfar platform MDIO bus and
pass the right intializations to the gianfar driver to make things work
again.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
A non-broken udev would autoload also the drivers for devices on the
pseries vio bus, like ibmveth, ibmvscsic and hvsc. This is similar to pci,
usb and ieee1394:
/lib/modules/`uname -r`/modules.alias
alias vio:TvscsiSIBM,v-scsi* ibmvscsic
alias vio:TnetworkSIBM,l-lan* ibmveth
alias vio:Tserial-serverShvterm2* hvcs
/events/debug.00004.pci.add.1394:MODALIAS='pci:v00001014d00000188sv00000000sd00000000bc06sc04i0f'
/events/debug.00005.pci.add.1509:MODALIAS='pci:v00008086d00001229sv00001014sd000001FFbc02sc00i00'
/events/debug.00026.vio.add.1519:MODALIAS='vio:TserialShvterm1'
/events/debug.00027.vio.add.1446:MODALIAS='vio:TvscsiSIBM,v-scsi'
/events/debug.00028.vio.add.1451:MODALIAS='vio:TnetworkSIBM,l-lan'
modprobe -v vio:TnetworkSIBM,l-lan
insmod /lib/modules/2.6.14-20051030_vio-ppc64/kernel/drivers/net/ibmveth.ko
Signed-off-by: Olaf Hering <olh@suse.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fixes mismerged Makefile that prevented the ppc85xx rapidio support from being
built.
Signed-off-by: Matt Porter <mporter@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
You could open the /proc/sys/net/ipv4/conf/<if>/<whatever> file, then
wait for interface to go away, try to grab as much memory as possible in
hope to hit the (kfreed) ctl_table. Then fill it with pointers to your
function. Then do read from file you've opened and if you are lucky,
you'll get it called as ->proc_handler() in kernel mode.
So this is at least an Oops and possibly more. It does depend on an
interface going away though, so less of a security risk than it would
otherwise be.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Patch from Nicolas Pitre
Make it completely deterministic and leave nothing to chance
(even if it had at worst 0.001% probability of failing).
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Ben Dooks
Force a watchdog reset if the system fails to
decompress properly.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Dirk Opfer
This patch updates the tosa machine to use the new SharpSL PCMCIA layer introduced with Patch #3093/1
Depends on #3093/1
Signed-off-by: Dirk Opfer <Dirk@Opfer-Online.de>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Richard Purdie
The Sharp SL-Cxx00 models have a combined power control for the SD
and CF slot 0. This patch adds hooks to the scoop driver to allow
machines to provide a custom control function for this and such a
function is added for spitz/akita/borzoi.
It also moves the gpio init code into the machine files as this
is machine dependent and differs between some models. A couple of
warnings when compiling for collie are also fixed.
Signed-off-by: Richard Purdie
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Ben Dooks
Fix the map_desc entries to use the new .pfn
initialiser for the Simtec BAST machine support.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Ben Dooks
Fix the initialisation of the map_desc fields
in the Thorcom VR1000 machine support to use
the new .pfn initialiser.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Dirk Opfer
This patch adds MMC, IRDA and UDC support to the Sharp SL-6000x device. Also it adds a platform device for the keyboard driver.
Signed-off-by: Dirk Opfer
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add infrastructure for supporting per-cpu local timers to update
the profiling information and update system time accounting.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Update comment on get_user_insn to the more general "pte lock", which may
or may not be the page_table_lock. Note vmtruncate handled like kswapd.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
arch/arm/kernel/irq.c:998:26: warning: Using plain integer as NULL pointer
arch/arm/kernel/smp.c:145:25: warning: Using plain integer as NULL pointer
arch/arm/kernel/smp.c:362:5: warning: symbol 'smp_call_function_on_cpu' was not declared. Should it be static?
drivers/video/amba-clcd.c:521:12: warning: symbol 'amba_clcdfb_init' was not declared. Should it be static?
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Nick Piggin
Christoph Hellwig
Olaf Hering
Adrian Bunk
Matt Porter
Kumar Gala
Al Viro
Linus Torvalds
Russell King
Nicolas Pitre
Ben Dooks
Dirk Opfer
Richard Purdie
Hugh Dickins