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authorPaul Mackerras <paulus@samba.org>2007-11-09 22:39:38 +0100
committerIngo Molnar <mingo@elte.hu>2007-11-09 22:39:38 +0100
commitfa13a5a1f25f671d084d8884be96fc48d9b68275 (patch)
tree97dae05bb5baef806a6dcbeed8b7eb5bdc61e4ae /arch/s390/kernel/vtime.c
parent9a41785cc43d88397f787a651ed7286a33f8462f (diff)
sched: restore deterministic CPU accounting on powerpc
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(). account_process_tick() now takes the task_struct * as an argument. Tested both with and without CONFIG_VIRT_CPU_ACCOUNTING. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/s390/kernel/vtime.c')
-rw-r--r--arch/s390/kernel/vtime.c8
1 files changed, 1 insertions, 7 deletions
diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c
index 84ff78de6ba..c5f05b3fb2c 100644
--- a/arch/s390/kernel/vtime.c
+++ b/arch/s390/kernel/vtime.c
@@ -32,7 +32,7 @@ static DEFINE_PER_CPU(struct vtimer_queue, virt_cpu_timer);
* Update process times based on virtual cpu times stored by entry.S
* to the lowcore fields user_timer, system_timer & steal_clock.
*/
-void account_tick_vtime(struct task_struct *tsk)
+void account_process_tick(struct task_struct *tsk, int user_tick)
{
cputime_t cputime;
__u64 timer, clock;
@@ -64,12 +64,6 @@ void account_tick_vtime(struct task_struct *tsk)
S390_lowcore.steal_clock -= cputime << 12;
account_steal_time(tsk, cputime);
}
-
- run_local_timers();
- if (rcu_pending(smp_processor_id()))
- rcu_check_callbacks(smp_processor_id(), rcu_user_flag);
- scheduler_tick();
- run_posix_cpu_timers(tsk);
}
/*