From fa13a5a1f25f671d084d8884be96fc48d9b68275 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Fri, 9 Nov 2007 22:39:38 +0100 Subject: 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 Signed-off-by: Ingo Molnar --- arch/s390/kernel/time.c | 4 ---- arch/s390/kernel/vtime.c | 8 +------- 2 files changed, 1 insertion(+), 11 deletions(-) (limited to 'arch/s390/kernel') diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c index a963fe81359..22b800ce212 100644 --- a/arch/s390/kernel/time.c +++ b/arch/s390/kernel/time.c @@ -145,12 +145,8 @@ void account_ticks(u64 time) do_timer(ticks); #endif -#ifdef CONFIG_VIRT_CPU_ACCOUNTING - account_tick_vtime(current); -#else while (ticks--) update_process_times(user_mode(get_irq_regs())); -#endif s390_do_profile(); } 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); } /* -- cgit v1.2.3