Since powerpc started using CONFIG_GENERIC_CLOCKEVENTS, the

deterministic CPU accounting (CONFIG_VIRT_CPU_ACCOUNTING) has been

broken on powerpc, because we end up counting user time twice: once in

timer_interrupt() and once in update_process_times().
This fixes the problem by pulling the code in update_process_times

that updates utime and stime into a separate function called

account_process_tick.  If CONFIG_VIRT_CPU_ACCOUNTING is not defined,

there is a version of account_process_tick in kernel/timer.c that

simply accounts a whole tick to either utime or stime as before.  If

CONFIG_VIRT_CPU_ACCOUNTING is defined, then arch code gets to

implement account_process_tick.
This also lets us simplify the s390 code a bit; it means that the s390

timer interrupt can now call update_process_times even when

CONFIG_VIRT_CPU_ACCOUNTING is turned on, and can just implement a

suitable account_process_tick().
Signed-off-by: Paul Mackerras <paulus@samba.org>

---

account_process_tick now takes the task_struct * as an argument.

Tested both with and without CONFIG_VIRT_CPU_ACCOUNTING.
 arch/powerpc/kernel/process.c |    2 +-

 arch/powerpc/kernel/time.c    |   25 +------------------------

 arch/s390/kernel/time.c       |    4 ----

 arch/s390/kernel/vtime.c      |    8 +-------

 include/linux/sched.h         |    1 +

 kernel/timer.c                |   21 ++++++++++++++-------

 6 files changed, 18 insertions(+), 43 deletions(-)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c

index b9d8837..41e13f4 100644

--- a/arch/powerpc/kernel/process.c

+++ b/arch/powerpc/kernel/process.c

@@ -350,7 +350,7 @@ struct task_struct *__switch_to(struct task_struct *prev,

 	local_irq_save(flags);
 	account_system_vtime(current);

-	account_process_vtime(current);

+	account_process_tick(current, 0);

 	calculate_steal_time();
 	last = _switch(old_thread, new_thread);

diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c

index 9eb3284..a70dfb7 100644

--- a/a...
[ message continues ]

thanks, applied.
	Ingo

-