Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched

[~andy/linux] / arch / powerpc / kernel / time.c

diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 863a5d6d9b1890626f5eceac08bc45304e6c13ce..4beb6329dfb7f9158b651d9abfcb2951465e00b8 100644 (file)
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -211,24 +211,45 @@ static u64 read_purr(void)
        return mftb();
 }
 
+/*
+ * Read the SPURR on systems that have it, otherwise the purr
+ */
+static u64 read_spurr(u64 purr)
+{
+       if (cpu_has_feature(CPU_FTR_SPURR))
+               return mfspr(SPRN_SPURR);
+       return purr;
+}
+
 /*
  * Account time for a transition between system, hard irq
  * or soft irq state.
  */
 void account_system_vtime(struct task_struct *tsk)
 {
-       u64 now, delta;
+       u64 now, nowscaled, delta, deltascaled;
        unsigned long flags;
 
        local_irq_save(flags);
        now = read_purr();
        delta = now - get_paca()->startpurr;
        get_paca()->startpurr = now;
+       nowscaled = read_spurr(now);
+       deltascaled = nowscaled - get_paca()->startspurr;
+       get_paca()->startspurr = nowscaled;
        if (!in_interrupt()) {
+               /* deltascaled includes both user and system time.
+                * Hence scale it based on the purr ratio to estimate
+                * the system time */
+               deltascaled = deltascaled * get_paca()->system_time /
+                       (get_paca()->system_time + get_paca()->user_time);
                delta += get_paca()->system_time;
                get_paca()->system_time = 0;
        }
        account_system_time(tsk, 0, delta);
+       get_paca()->purrdelta = delta;
+       account_system_time_scaled(tsk, deltascaled);
+       get_paca()->spurrdelta = deltascaled;
        local_irq_restore(flags);
 }
 
@@ -238,25 +259,19 @@ void account_system_vtime(struct task_struct *tsk)
  * user and system time records.
  * Must be called with interrupts disabled.
  */
-void account_process_vtime(struct task_struct *tsk)
+void account_process_tick(struct task_struct *tsk, int user_tick)
 {
-       cputime_t utime;
+       cputime_t utime, utimescaled;
 
        utime = get_paca()->user_time;
        get_paca()->user_time = 0;
        account_user_time(tsk, utime);
-}
 
-static void account_process_time(struct pt_regs *regs)
-{
-       int cpu = smp_processor_id();
-
-       account_process_vtime(current);
-       run_local_timers();
-       if (rcu_pending(cpu))
-               rcu_check_callbacks(cpu, user_mode(regs));
-       scheduler_tick();
-       run_posix_cpu_timers(current);
+       /* Estimate the scaled utime by scaling the real utime based
+        * on the last spurr to purr ratio */
+       utimescaled = utime * get_paca()->spurrdelta / get_paca()->purrdelta;
+       get_paca()->spurrdelta = get_paca()->purrdelta = 0;
+       account_user_time_scaled(tsk, utimescaled);
 }
 
 /*
@@ -266,6 +281,7 @@ struct cpu_purr_data {
        int     initialized;                    /* thread is running */
        u64     tb;                     /* last TB value read */
        u64     purr;                   /* last PURR value read */
+       u64     spurr;                  /* last SPURR value read */
 };
 
 /*
@@ -347,7 +363,6 @@ static void snapshot_purr(void)
 
 #else /* ! CONFIG_VIRT_CPU_ACCOUNTING */
 #define calc_cputime_factors()
-#define account_process_time(regs)     update_process_times(user_mode(regs))
 #define calculate_steal_time()         do { } while (0)
 #endif
 
@@ -558,7 +573,7 @@ void timer_interrupt(struct pt_regs * regs)
                /* not time for this event yet */
                now = per_cpu(decrementer_next_tb, cpu) - now;
                if (now <= DECREMENTER_MAX)
-                       set_dec((unsigned int)now - 1);
+                       set_dec((int)now);
                return;
        }
        old_regs = set_irq_regs(regs);
@@ -571,20 +586,8 @@ void timer_interrupt(struct pt_regs * regs)
                get_lppaca()->int_dword.fields.decr_int = 0;
 #endif
 
-       /*
-        * We cannot disable the decrementer, so in the period
-        * between this cpu's being marked offline in cpu_online_map
-        * and calling stop-self, it is taking timer interrupts.
-        * Avoid calling into the scheduler rebalancing code if this
-        * is the case.
-        */
-       if (!cpu_is_offline(cpu))
-               account_process_time(regs);
-
        if (evt->event_handler)
                evt->event_handler(evt);
-       else
-               evt->set_next_event(DECREMENTER_MAX, evt);
 
 #ifdef CONFIG_PPC_ISERIES
        if (firmware_has_feature(FW_FEATURE_ISERIES) && hvlpevent_is_pending())
@@ -808,9 +811,6 @@ static int decrementer_set_next_event(unsigned long evt,
                                      struct clock_event_device *dev)
 {
        __get_cpu_var(decrementer_next_tb) = get_tb_or_rtc() + evt;
-       /* The decrementer interrupts on the 0 -> -1 transition */
-       if (evt)
-               --evt;
        set_dec(evt);
        return 0;
 }
@@ -843,7 +843,8 @@ void init_decrementer_clockevent(void)
                                             decrementer_clockevent.shift);
        decrementer_clockevent.max_delta_ns =
                clockevent_delta2ns(DECREMENTER_MAX, &decrementer_clockevent);
-       decrementer_clockevent.min_delta_ns = 1000;
+       decrementer_clockevent.min_delta_ns =
+               clockevent_delta2ns(2, &decrementer_clockevent);
 
        register_decrementer_clockevent(cpu);
 }