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Merge branch 'akpm'

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* akpm:
  kernel/smp.c: consolidate writes in smp_call_function_interrupt()
  kernel/smp.c: fix smp_call_function_many() SMP race
  memcg: correctly order reading PCG_USED and pc->mem_cgroup
  backlight: fix 88pm860x_bl macro collision
  drivers/leds/ledtrig-gpio.c: make output match input, tighten input checking
  MAINTAINERS: update Atmel AT91 entry
  mm: fix truncate_setsize() comment
  memcg: fix rmdir, force_empty with THP
  memcg: fix LRU accounting with THP
  memcg: fix USED bit handling at uncharge in THP
  memcg: modify accounting function for supporting THP better
  fs/direct-io.c: don't try to allocate more than BIO_MAX_PAGES in a bio
  mm: compaction: prevent division-by-zero during user-requested compaction
  mm/vmscan.c: remove duplicate include of compaction.h
  memblock: fix memblock_is_region_memory()
  thp: keep highpte mapped until it is no longer needed
  kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT
This commit is contained in:
Linus Torvalds
2011-01-20 17:02:14 -08:00
parent fc887b15d9 225c8e010f
commit 8d99641f6c
310 changed files with 643 additions and 536 deletions
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51
kernel/smp.c
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@@ -194,23 +194,52 @@ void generic_smp_call_function_interrupt(void)
*/
list_for_each_entry_rcu(data, &call_function.queue, csd.list) {
int refs;
void (*func) (void *info);
if (!cpumask_test_and_clear_cpu(cpu, data->cpumask))
/*
* Since we walk the list without any locks, we might
* see an entry that was completed, removed from the
* list and is in the process of being reused.
*
* We must check that the cpu is in the cpumask before
* checking the refs, and both must be set before
* executing the callback on this cpu.
*/
if (!cpumask_test_cpu(cpu, data->cpumask))
continue;
smp_rmb();
if (atomic_read(&data->refs) == 0)
continue;
func = data->csd.func; /* for later warn */
data->csd.func(data->csd.info);
/*
* If the cpu mask is not still set then it enabled interrupts,
* we took another smp interrupt, and executed the function
* twice on this cpu. In theory that copy decremented refs.
*/
if (!cpumask_test_and_clear_cpu(cpu, data->cpumask)) {
WARN(1, "%pS enabled interrupts and double executed\n",
func);
continue;
}
refs = atomic_dec_return(&data->refs);
WARN_ON(refs < 0);
if (!refs) {
raw_spin_lock(&call_function.lock);
list_del_rcu(&data->csd.list);
raw_spin_unlock(&call_function.lock);
}
if (refs)
continue;
WARN_ON(!cpumask_empty(data->cpumask));
raw_spin_lock(&call_function.lock);
list_del_rcu(&data->csd.list);
raw_spin_unlock(&call_function.lock);
csd_unlock(&data->csd);
}
@@ -454,11 +483,21 @@ void smp_call_function_many(const struct cpumask *mask,
data = &__get_cpu_var(cfd_data);
csd_lock(&data->csd);
BUG_ON(atomic_read(&data->refs) || !cpumask_empty(data->cpumask));
data->csd.func = func;
data->csd.info = info;
cpumask_and(data->cpumask, mask, cpu_online_mask);
cpumask_clear_cpu(this_cpu, data->cpumask);
/*
* To ensure the interrupt handler gets an complete view
* we order the cpumask and refs writes and order the read
* of them in the interrupt handler. In addition we may
* only clear our own cpu bit from the mask.
*/
smp_wmb();
atomic_set(&data->refs, cpumask_weight(data->cpumask));
raw_spin_lock_irqsave(&call_function.lock, flags);