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Merge branch 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

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* 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (33 commits)
  lockdep: fix deadlock in lockdep_trace_alloc
  lockdep: annotate reclaim context (__GFP_NOFS), fix SLOB
  lockdep: annotate reclaim context (__GFP_NOFS), fix
  lockdep: build fix for !PROVE_LOCKING
  lockstat: warn about disabled lock debugging
  lockdep: use stringify.h
  lockdep: simplify check_prev_add_irq()
  lockdep: get_user_chars() redo
  lockdep: simplify get_user_chars()
  lockdep: add comments to mark_lock_irq()
  lockdep: remove macro usage from mark_held_locks()
  lockdep: fully reduce mark_lock_irq()
  lockdep: merge the !_READ mark_lock_irq() helpers
  lockdep: merge the _READ mark_lock_irq() helpers
  lockdep: simplify mark_lock_irq() helpers #3
  lockdep: further simplify mark_lock_irq() helpers
  lockdep: simplify the mark_lock_irq() helpers
  lockdep: split up mark_lock_irq()
  lockdep: generate usage strings
  lockdep: generate the state bit definitions
  ...
This commit is contained in:
Linus Torvalds 2009-03-30 17:17:35 -07:00
commit c4e1aa67ed
21 changed files with 731 additions and 380 deletions
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71
kernel/sched.c
View file

@ -4942,15 +4942,13 @@ pick_next_task(struct rq *rq)
/*
* 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);
@ -5007,13 +5005,80 @@ need_resched_nonpreemptible:
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