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authorPaul Mackerras <paulus@samba.org>2007-11-09 16:39:38 -0500
committerIngo Molnar <mingo@elte.hu>2007-11-09 16:39:38 -0500
commitfa13a5a1f25f671d084d8884be96fc48d9b68275 (patch)
tree97dae05bb5baef806a6dcbeed8b7eb5bdc61e4ae /kernel/timer.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 'kernel/timer.c')
-rw-r--r--kernel/timer.c21
1 files changed, 14 insertions, 7 deletions
diff --git a/kernel/timer.c b/kernel/timer.c
index 00e44e2afd67..a05817c021d6 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -817,6 +817,19 @@ unsigned long next_timer_interrupt(void)
817 817
818#endif 818#endif
819 819
820#ifndef CONFIG_VIRT_CPU_ACCOUNTING
821void account_process_tick(struct task_struct *p, int user_tick)
822{
823 if (user_tick) {
824 account_user_time(p, jiffies_to_cputime(1));
825 account_user_time_scaled(p, jiffies_to_cputime(1));
826 } else {
827 account_system_time(p, HARDIRQ_OFFSET, jiffies_to_cputime(1));
828 account_system_time_scaled(p, jiffies_to_cputime(1));
829 }
830}
831#endif
832
820/* 833/*
821 * Called from the timer interrupt handler to charge one tick to the current 834 * Called from the timer interrupt handler to charge one tick to the current
822 * process. user_tick is 1 if the tick is user time, 0 for system. 835 * process. user_tick is 1 if the tick is user time, 0 for system.
@@ -827,13 +840,7 @@ void update_process_times(int user_tick)
827 int cpu = smp_processor_id(); 840 int cpu = smp_processor_id();
828 841
829 /* Note: this timer irq context must be accounted for as well. */ 842 /* Note: this timer irq context must be accounted for as well. */
830 if (user_tick) { 843 account_process_tick(p, user_tick);
831 account_user_time(p, jiffies_to_cputime(1));
832 account_user_time_scaled(p, jiffies_to_cputime(1));
833 } else {
834 account_system_time(p, HARDIRQ_OFFSET, jiffies_to_cputime(1));
835 account_system_time_scaled(p, jiffies_to_cputime(1));
836 }
837 run_local_timers(); 844 run_local_timers();
838 if (rcu_pending(cpu)) 845 if (rcu_pending(cpu))
839 rcu_check_callbacks(cpu, user_tick); 846 rcu_check_callbacks(cpu, user_tick);