Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[karo-tx-linux.git] / kernel / sched / cputime.c

diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index a7959e05a9d56ff1f53ef43cb97f2b127c018d30..99947919e30bc68963d3bfa937ebad8a2c90ba87 100644 (file)
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -121,7 +121,7 @@ static inline void task_group_account_field(struct task_struct *p, int index,
         * is the only cgroup, then nothing else should be necessary.
         *
         */
-       __get_cpu_var(kernel_cpustat).cpustat[index] += tmp;
+       __this_cpu_add(kernel_cpustat.cpustat[index], tmp);
 
        cpuacct_account_field(p, index, tmp);
 }
@@ -378,11 +378,8 @@ static inline void irqtime_account_process_tick(struct task_struct *p, int user_
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
 
 #ifndef __ARCH_HAS_VTIME_TASK_SWITCH
-void vtime_task_switch(struct task_struct *prev)
+void vtime_common_task_switch(struct task_struct *prev)
 {
-       if (!vtime_accounting_enabled())
-               return;
-
        if (is_idle_task(prev))
                vtime_account_idle(prev);
        else
@@ -404,11 +401,8 @@ void vtime_task_switch(struct task_struct *prev)
  * vtime_account().
  */
 #ifndef __ARCH_HAS_VTIME_ACCOUNT
-void vtime_account_irq_enter(struct task_struct *tsk)
+void vtime_common_account_irq_enter(struct task_struct *tsk)
 {
-       if (!vtime_accounting_enabled())
-               return;
-
        if (!in_interrupt()) {
                /*
                 * If we interrupted user, context_tracking_in_user()
@@ -428,7 +422,7 @@ void vtime_account_irq_enter(struct task_struct *tsk)
        }
        vtime_account_system(tsk);
 }
-EXPORT_SYMBOL_GPL(vtime_account_irq_enter);
+EXPORT_SYMBOL_GPL(vtime_common_account_irq_enter);
 #endif /* __ARCH_HAS_VTIME_ACCOUNT */
 #endif /* CONFIG_VIRT_CPU_ACCOUNTING */
 
@@ -557,16 +551,7 @@ static void cputime_adjust(struct task_cputime *curr,
                           struct cputime *prev,
                           cputime_t *ut, cputime_t *st)
 {
-       cputime_t rtime, stime, utime, total;
-
-       if (vtime_accounting_enabled()) {
-               *ut = curr->utime;
-               *st = curr->stime;
-               return;
-       }
-
-       stime = curr->stime;
-       total = stime + curr->utime;
+       cputime_t rtime, stime, utime;
 
        /*
         * Tick based cputime accounting depend on random scheduling
@@ -588,13 +573,19 @@ static void cputime_adjust(struct task_cputime *curr,
        if (prev->stime + prev->utime >= rtime)
                goto out;
 
-       if (total) {
+       stime = curr->stime;
+       utime = curr->utime;
+
+       if (utime == 0) {
+               stime = rtime;
+       } else if (stime == 0) {
+               utime = rtime;
+       } else {
+               cputime_t total = stime + utime;
+
                stime = scale_stime((__force u64)stime,
                                    (__force u64)rtime, (__force u64)total);
                utime = rtime - stime;
-       } else {
-               stime = rtime;
-               utime = 0;
        }
 
        /*
@@ -664,23 +655,17 @@ static void __vtime_account_system(struct task_struct *tsk)
 
 void vtime_account_system(struct task_struct *tsk)
 {
-       if (!vtime_accounting_enabled())
-               return;
-
        write_seqlock(&tsk->vtime_seqlock);
        __vtime_account_system(tsk);
        write_sequnlock(&tsk->vtime_seqlock);
 }
 
-void vtime_account_irq_exit(struct task_struct *tsk)
+void vtime_gen_account_irq_exit(struct task_struct *tsk)
 {
-       if (!vtime_accounting_enabled())
-               return;
-
        write_seqlock(&tsk->vtime_seqlock);
+       __vtime_account_system(tsk);
        if (context_tracking_in_user())
                tsk->vtime_snap_whence = VTIME_USER;
-       __vtime_account_system(tsk);
        write_sequnlock(&tsk->vtime_seqlock);
 }
 
@@ -688,12 +673,8 @@ void vtime_account_user(struct task_struct *tsk)
 {
        cputime_t delta_cpu;
 
-       if (!vtime_accounting_enabled())
-               return;
-
-       delta_cpu = get_vtime_delta(tsk);
-
        write_seqlock(&tsk->vtime_seqlock);
+       delta_cpu = get_vtime_delta(tsk);
        tsk->vtime_snap_whence = VTIME_SYS;
        account_user_time(tsk, delta_cpu, cputime_to_scaled(delta_cpu));
        write_sequnlock(&tsk->vtime_seqlock);
@@ -701,22 +682,27 @@ void vtime_account_user(struct task_struct *tsk)
 
 void vtime_user_enter(struct task_struct *tsk)
 {
-       if (!vtime_accounting_enabled())
-               return;
-
        write_seqlock(&tsk->vtime_seqlock);
-       tsk->vtime_snap_whence = VTIME_USER;
        __vtime_account_system(tsk);
+       tsk->vtime_snap_whence = VTIME_USER;
        write_sequnlock(&tsk->vtime_seqlock);
 }
 
 void vtime_guest_enter(struct task_struct *tsk)
 {
+       /*
+        * The flags must be updated under the lock with
+        * the vtime_snap flush and update.
+        * That enforces a right ordering and update sequence
+        * synchronization against the reader (task_gtime())
+        * that can thus safely catch up with a tickless delta.
+        */
        write_seqlock(&tsk->vtime_seqlock);
        __vtime_account_system(tsk);
        current->flags |= PF_VCPU;
        write_sequnlock(&tsk->vtime_seqlock);
 }
+EXPORT_SYMBOL_GPL(vtime_guest_enter);
 
 void vtime_guest_exit(struct task_struct *tsk)
 {
@@ -725,6 +711,7 @@ void vtime_guest_exit(struct task_struct *tsk)
        current->flags &= ~PF_VCPU;
        write_sequnlock(&tsk->vtime_seqlock);
 }
+EXPORT_SYMBOL_GPL(vtime_guest_exit);
 
 void vtime_account_idle(struct task_struct *tsk)
 {
@@ -733,11 +720,6 @@ void vtime_account_idle(struct task_struct *tsk)
        account_idle_time(delta_cpu);
 }
 
-bool vtime_accounting_enabled(void)
-{
-       return context_tracking_active();
-}
-
 void arch_vtime_task_switch(struct task_struct *prev)
 {
        write_seqlock(&prev->vtime_seqlock);