Re: [dpdk-dev] Added Spinlock to l3fwd-vf example to prevent race conditioning

[Neil Horman <nhorman@tuxdriver.com>]

On Tue, Jul 08, 2014 at 12:16:24PM +0100, Daniel Mrzyglod wrote:
> Signed-off-by: Daniel Mrzyglod <danielx.t.mrzyglod@intel.com>
> 
> ---
> examples/l3fwd-vf/main.c |    6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/examples/l3fwd-vf/main.c b/examples/l3fwd-vf/main.c
> index 2ca5c21..57852d0 100644
> --- a/examples/l3fwd-vf/main.c
> +++ b/examples/l3fwd-vf/main.c
> @@ -54,6 +54,7 @@
>  #include <rte_per_lcore.h>
>  #include <rte_launch.h>
>  #include <rte_atomic.h>
> +#include <rte_spinlock.h>
>  #include <rte_cycles.h>
>  #include <rte_prefetch.h>
>  #include <rte_lcore.h>
> @@ -328,7 +329,7 @@ struct lcore_conf {
>  } __rte_cache_aligned;
>  
>  static struct lcore_conf lcore_conf[RTE_MAX_LCORE];
> -
> +static rte_spinlock_t spinlock_conf[RTE_MAX_ETHPORTS]={RTE_SPINLOCK_INITIALIZER};
>  /* Send burst of packets on an output interface */
>  static inline int
>  send_burst(struct lcore_conf *qconf, uint16_t n, uint8_t port)
> @@ -340,7 +341,10 @@ send_burst(struct lcore_conf *qconf, uint16_t n, uint8_t port)
>  	queueid = qconf->tx_queue_id;
>  	m_table = (struct rte_mbuf **)qconf->tx_mbufs[port].m_table;
>  
> +	rte_spinlock_lock(&spinlock_conf[port]) ;
>  	ret = rte_eth_tx_burst(port, queueid, m_table, n);
> +	rte_spinlock_unlock(&spinlock_conf[port]);
> +	
>  	if (unlikely(ret < n)) {
>  		do {
>  			rte_pktmbuf_free(m_table[ret]);

Acked-by: Neil Horman <nhorman@tuxdriver.com>

Though, that said, doesn't it seem to anyone else like serialization of enqueue
to a port should be the responsibility of the library, not the application?

Neil