[ltt-dev] [UST PATCH] UST synchronization fix

[Pierre-Marc Fournier]

Merged, thanks.

On 08/11/2010 10:13 AM, Mathieu Desnoyers wrote:
> Missing smp_wmb() at subbuffer switch.
>
> Signed-off-by: Mathieu Desnoyers<mathieu.desnoyers at efficios.com>
> ---
>   git/ust/libust/buffers.c |    6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
>
> Index: ust/libust/buffers.c
> ===================================================================
> --- ust/libust/buffers.c	2010-08-10 16:16:39.000000000 -0400
> +++ ust/libust/buffers.c	2010-08-10 16:19:59.000000000 -0400
> @@ -858,7 +858,7 @@ static void ltt_reserve_switch_old_subbu
>   	 * This compiler barrier is upgraded into a smp_wmb() by the IPI
>   	 * sent by get_subbuf() when it does its smp_rmb().
>   	 */
> -	barrier();
> +	smp_wmb();
>   	uatomic_add(&buf->commit_count[oldidx].cc, padding_size);
>   	commit_count = uatomic_read(&buf->commit_count[oldidx].cc);
>   	ltt_check_deliver(chan, buf, offsets->old - 1, commit_count, oldidx);
> @@ -887,7 +887,7 @@ static void ltt_reserve_switch_new_subbu
>   	 * This compiler barrier is upgraded into a smp_wmb() by the IPI
>   	 * sent by get_subbuf() when it does its smp_rmb().
>   	 */
> -	barrier();
> +	smp_wmb();
>   	uatomic_add(&buf->commit_count[beginidx].cc, ltt_subbuffer_header_size());
>   	commit_count = uatomic_read(&buf->commit_count[beginidx].cc);
>   	/* Check if the written buffer has to be delivered */
> @@ -932,7 +932,7 @@ static void ltt_reserve_end_switch_curre
>   	 * This compiler barrier is upgraded into a smp_wmb() by the IPI
>   	 * sent by get_subbuf() when it does its smp_rmb().
>   	 */
> -	barrier();
> +	smp_wmb();
>   	uatomic_add(&buf->commit_count[endidx].cc, padding_size);
>   	commit_count = uatomic_read(&buf->commit_count[endidx].cc);
>   	ltt_check_deliver(chan, buf,