Re: [patch] generic-ipi: remove kmalloc, cleanup

Peter Zijlstra
2009-02-12T12:34:21Z

On Thu, 2009-02-12 at 13:09 +0100, Peter Zijlstra wrote:

> @@ -137,8 +137,10 @@ void generic_smp_call_function_interrupt(void)
> */
> smp_wmb();
> data->csd.flags &= ~CSD_FLAG_WAIT;
> - }
> - if (data->csd.flags & CSD_FLAG_ALLOC)
> + } else if (data->csd.flags & CSD_FLAG_LOCK) {
> + smp_wmb();
> + data->csd.flags &= ~CSD_FLAG_LOCK;
> + } else if (data->csd.flags & CSD_FLAG_ALLOC)
> call_rcu(&data->rcu_head, rcu_free_call_data);
> }
> rcu_read_unlock();

Hmm, I think this bit ought to go in rcu_free_call_data(), otherwise we
can have that same race again..

I'd better put a comment in on why we use RCU here.