return 0;
}
/********** Helpers for find_busiest_group ************************/
-/**
+/*
* sd_lb_stats - Structure to store the statistics of a sched_domain
* during load balancing.
*/
#endif
};
-/**
+/*
* sg_lb_stats - stats of a sched_group required for load_balancing
*/
struct sg_lb_stats {
}
/**
- * check_power_save_busiest_group - Check if we have potential to perform
- * some power-savings balance. If yes, set the busiest group to be
- * the least loaded group in the sched_domain, so that it's CPUs can
- * be put to idle.
- *
+ * check_power_save_busiest_group - see if there is potential for some power-savings balance
* @sds: Variable containing the statistics of the sched_domain
* under consideration.
* @this_cpu: Cpu at which we're currently performing load-balancing.
* @imbalance: Variable to store the imbalance.
*
+ * Description:
+ * Check if we have potential to perform some power-savings balance.
+ * If yes, set the busiest group to be the least loaded group in the
+ * sched_domain, so that it's CPUs can be put to idle.
+ *
* Returns 1 if there is potential to perform power-savings balance.
* Else returns 0.
*/
/*
* schedule() is the main scheduler function.
*/
-asmlinkage void __sched schedule(void)
+asmlinkage void __sched __schedule(void)
{
struct task_struct *prev, *next;
unsigned long *switch_count;
struct rq *rq;
int cpu;
-need_resched:
- preempt_disable();
cpu = smp_processor_id();
rq = cpu_rq(cpu);
rcu_qsctr_inc(cpu);
if (unlikely(reacquire_kernel_lock(current) < 0))
goto need_resched_nonpreemptible;
+}
+asmlinkage void __sched schedule(void)
+{
+need_resched:
+ preempt_disable();
+ __schedule();
preempt_enable_no_resched();
if (unlikely(test_thread_flag(TIF_NEED_RESCHED)))
goto need_resched;
}
EXPORT_SYMBOL(schedule);
+#ifdef CONFIG_SMP
+/*
+ * Look out! "owner" is an entirely speculative pointer
+ * access and not reliable.
+ */
+int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner)
+{
+ unsigned int cpu;
+ struct rq *rq;
+
+ if (!sched_feat(OWNER_SPIN))
+ return 0;
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+ /*
+ * Need to access the cpu field knowing that
+ * DEBUG_PAGEALLOC could have unmapped it if
+ * the mutex owner just released it and exited.
+ */
+ if (probe_kernel_address(&owner->cpu, cpu))
+ goto out;
+#else
+ cpu = owner->cpu;
+#endif
+
+ /*
+ * Even if the access succeeded (likely case),
+ * the cpu field may no longer be valid.
+ */
+ if (cpu >= nr_cpumask_bits)
+ goto out;
+
+ /*
+ * We need to validate that we can do a
+ * get_cpu() and that we have the percpu area.
+ */
+ if (!cpu_online(cpu))
+ goto out;
+
+ rq = cpu_rq(cpu);
+
+ for (;;) {
+ /*
+ * Owner changed, break to re-assess state.
+ */
+ if (lock->owner != owner)
+ break;
+
+ /*
+ * Is that owner really running on that cpu?
+ */
+ if (task_thread_info(rq->curr) != owner || need_resched())
+ return 0;
+
+ cpu_relax();
+ }
+out:
+ return 1;
+}
+#endif
+
#ifdef CONFIG_PREEMPT
/*
* this is the entry point to schedule() from in-kernel preemption
printk(KERN_CONT " %016lx ", thread_saved_pc(p));
#endif
#ifdef CONFIG_DEBUG_STACK_USAGE
- {
- unsigned long *n = end_of_stack(p);
- while (!*n)
- n++;
- free = (unsigned long)n - (unsigned long)end_of_stack(p);
- }
+ free = stack_not_used(p);
#endif
printk(KERN_CONT "%5lu %5d %6d\n", free,
task_pid_nr(p), task_pid_nr(p->real_parent));
static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu)
{
- u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu);
+ u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
u64 data;
#ifndef CONFIG_64BIT
static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val)
{
- u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu);
+ u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
#ifndef CONFIG_64BIT
/*
ca = task_ca(tsk);
for (; ca; ca = ca->parent) {
- u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu);
+ u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
*cpuusage += cputime;
}
}