[ltt-dev] [PATCH 6/7] urcu, call_rcu: Cleanup call_rcu_data pointers before used in child

[Paul E. McKenney]

On Wed, Sep 28, 2011 at 04:34:32PM +0800, Lai Jiangshan wrote:
> Signed-off-by: Lai Jiangshan <laijs at cn.fujitsu.com>
> ---
>  urcu-call-rcu-impl.h |    6 ++++++
>  1 files changed, 6 insertions(+), 0 deletions(-)
> 
> diff --git a/urcu-call-rcu-impl.h b/urcu-call-rcu-impl.h
> index 65c1c7a..3c68ae7 100644
> --- a/urcu-call-rcu-impl.h
> +++ b/urcu-call-rcu-impl.h
> @@ -686,6 +686,12 @@ void call_rcu_after_fork_child(void)
>  	default_call_rcu_data = NULL;
>  	(void)get_default_call_rcu_data();
> 
> +	/* Cleanup call_rcu_data pointers before used */
> +	maxcpus = 0;
> +	free(per_cpu_call_rcu_data);
> +	per_cpu_call_rcu_data = NULL;

Good catch!  I would expect that the number of CPUs would be the
same for the child as it was for the parent, but doesn't hurt to
make the child start over.

> +	thread_call_rcu_data = NULL;

Isn't thread_call_rcu_data already NULL due to the child being a new
thread and the C initialization-to-zero rules?

							Thanx, Paul

> +
>  	/* Dispose of all of the rest of the call_rcu_data structures. */
>  	cds_list_for_each_entry_safe(crdp, next, &call_rcu_data_list, list) {
>  		if (crdp == default_call_rcu_data)
> -- 
> 1.7.4.4
>