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Merge tag 'v3.16-rc5' into sched/core, to refresh the branch before applying bigger tree-wide changes

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Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Ingo Molnar
2014-07-16 15:10:07 +02:00
parent e720fff634 1795cd9b3a
commit d26fad5b38
1117 changed files with 13948 additions and 8175 deletions
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57
kernel/smp.c
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@@ -30,6 +30,8 @@ static DEFINE_PER_CPU_SHARED_ALIGNED(struct call_function_data, cfd_data);
static DEFINE_PER_CPU_SHARED_ALIGNED(struct llist_head, call_single_queue);
static void flush_smp_call_function_queue(bool warn_cpu_offline);
static int
hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu)
{
@@ -52,12 +54,27 @@ hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu)
#ifdef CONFIG_HOTPLUG_CPU
case CPU_UP_CANCELED:
case CPU_UP_CANCELED_FROZEN:
/* Fall-through to the CPU_DEAD[_FROZEN] case. */
case CPU_DEAD:
case CPU_DEAD_FROZEN:
free_cpumask_var(cfd->cpumask);
free_percpu(cfd->csd);
break;
case CPU_DYING:
case CPU_DYING_FROZEN:
/*
* The IPIs for the smp-call-function callbacks queued by other
* CPUs might arrive late, either due to hardware latencies or
* because this CPU disabled interrupts (inside stop-machine)
* before the IPIs were sent. So flush out any pending callbacks
* explicitly (without waiting for the IPIs to arrive), to
* ensure that the outgoing CPU doesn't go offline with work
* still pending.
*/
flush_smp_call_function_queue(false);
break;
#endif
};
@@ -178,23 +195,47 @@ static int generic_exec_single(int cpu, struct call_single_data *csd,
return 0;
}
/*
* Invoked by arch to handle an IPI for call function single. Must be
* called from the arch with interrupts disabled.
/**
* generic_smp_call_function_single_interrupt - Execute SMP IPI callbacks
*
* Invoked by arch to handle an IPI for call function single.
* Must be called with interrupts disabled.
*/
void generic_smp_call_function_single_interrupt(void)
{
flush_smp_call_function_queue(true);
}
/**
* flush_smp_call_function_queue - Flush pending smp-call-function callbacks
*
* @warn_cpu_offline: If set to 'true', warn if callbacks were queued on an
* offline CPU. Skip this check if set to 'false'.
*
* Flush any pending smp-call-function callbacks queued on this CPU. This is
* invoked by the generic IPI handler, as well as by a CPU about to go offline,
* to ensure that all pending IPI callbacks are run before it goes completely
* offline.
*
* Loop through the call_single_queue and run all the queued callbacks.
* Must be called with interrupts disabled.
*/
static void flush_smp_call_function_queue(bool warn_cpu_offline)
{
struct llist_head *head;
struct llist_node *entry;
struct call_single_data *csd, *csd_next;
static bool warned;
entry = llist_del_all(&__get_cpu_var(call_single_queue));
WARN_ON(!irqs_disabled());
head = &__get_cpu_var(call_single_queue);
entry = llist_del_all(head);
entry = llist_reverse_order(entry);
/*
* Shouldn't receive this interrupt on a cpu that is not yet online.
*/
if (unlikely(!cpu_online(smp_processor_id()) && !warned)) {
/* There shouldn't be any pending callbacks on an offline CPU. */
if (unlikely(warn_cpu_offline && !cpu_online(smp_processor_id()) &&
!warned && !llist_empty(head))) {
warned = true;
WARN(1, "IPI on offline CPU %d\n", smp_processor_id());