linux.git/arch/arm/kernel/process.c, branch v2.6.16

[ARM] 3363/1: [cleanup] process.c - fix warnings

2006-03-15T23:17:23+00:00

Patch from Ben Dooks

Fix the following warnings from sparse:

arch/arm/kernel/process.c:86:6: warning: symbol 'default_idle' was not declared. Should it be static?
arch/arm/kernel/process.c:378:5: warning: symbol 'dump_fpu' was not declared.   Should it be static?

Include  for dump_fpu() decleration, and
make default_idle() static as it is not used outside the file.

Signed-off-by: Ben Dooks 
Signed-off-by: Russell King

[PATCH] arm: task_stack_page()

2006-01-12T17:08:56+00:00

Signed-off-by: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] arm: end_of_stack()

2006-01-12T17:08:56+00:00

Signed-off-by: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] arm: task_pt_regs()

2006-01-12T17:08:55+00:00

Signed-off-by: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] arm: task_thread_info()

2006-01-12T17:08:55+00:00

Signed-off-by: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[ARM] Cleanup ARM includes

2006-01-03T17:39:34+00:00

arch/arm/kernel/entry-armv.S has contained a comment suggesting
that asm/hardware.h and asm/arch/irqs.h should be moved into the
asm/arch/entry-macro.S include.  So move the includes to these
two files as required.

Add missing includes (asm/hardware.h, asm/io.h) to asm/arch/system.h
includes which use those facilities, and remove asm/io.h from
kernel/process.c.

Remove other unnecessary includes from arch/arm/kernel, arch/arm/mm
and arch/arm/mach-footbridge.

Signed-off-by: Russell King

Merge master.kernel.org:/home/rmk/linux-2.6-arm

2005-11-09T16:55:53+00:00

[PATCH] sched: resched and cpu_idle rework

2005-11-09T15:56:33+00:00

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 
Cc: Ingo Molnar 
Cc: Con Kolivas 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] sched: disable preempt in idle tasks

2005-11-09T15:56:33+00:00

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 

  PPC build fix

From: Yoichi Yuasa 

  MIPS build fix

Signed-off-by: Nick Piggin 
Signed-off-by: Yoichi Yuasa 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[ARM] 3100/1: simplify a pointer computation

2005-11-09T14:09:31+00:00

Patch from Nicolas Pitre

Looks clearer this way.

Signed-off-by: Nicolas Pitre 
Signed-off-by: Russell King