lkml.org 
[lkml]   [2009]   [Jul]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 3/3 -mm] generic-ipi: fix the race between generic_smp_call_function_*() and hotplug_cfd()
From
Date
On Wed, 2009-07-29 at 16:31 -0700, Andrew Morton wrote:

> -void generic_smp_call_function_interrupt(void)
> +static void
> +__generic_smp_call_function_interrupt(int cpu, int run_callbacks)
> {
> struct call_function_data *data;
> - int cpu = smp_processor_id();
>
> /*
> * Ensure entry is visible on call_function_queue after we have
> @@ -169,12 +165,18 @@ void generic_smp_call_function_interrupt

> +static void
> +__generic_smp_call_function_single_interrupt(int cpu, int run_callbacks)
> {
> - struct call_single_queue *q = &__get_cpu_var(call_single_queue);
> + struct call_single_queue *q = &per_cpu(call_single_queue, cpu);
> unsigned int data_flags;
> LIST_HEAD(list);
>

It introduces this run_callbacks thing to two functions, but nothing
actually uses that... makes me suspicious there's something missing.


> case CPU_DEAD_FROZEN:
> + local_irq_save(flags);
> + __generic_smp_call_function_interrupt(cpu, 0);
> + __generic_smp_call_function_single_interrupt(cpu, 0);
> + local_irq_restore(flags);

Doing the callbacks from a different cpu than they were queued on seems
like a fine way to mess things up.


\
 
 \ /
  Last update: 2009-07-30 08:51    [from the cache]
©2003-2011 Jasper Spaans