Re: [dpdk-dev] [PATCH] mbuf: decrease refcnt when detaching

["Ananyev, Konstantin" <konstantin.ananyev@intel.com>]

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Hiroyuki Mikita
> Sent: Sunday, May 15, 2016 4:51 PM
> To: olivier.matz@6wind.com
> Cc: dev@dpdk.org
> Subject: [dpdk-dev] [PATCH] mbuf: decrease refcnt when detaching
> 
> The rte_pktmbuf_detach() function should decrease refcnt on a direct
> buffer.

Hmm, why is that?
What's wrong with the current approach?
Konstantin

> 
> Signed-off-by: Hiroyuki Mikita <h.mikita89@gmail.com>
> ---
>  lib/librte_mbuf/rte_mbuf.h | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
> index 529debb..3b117ca 100644
> --- a/lib/librte_mbuf/rte_mbuf.h
> +++ b/lib/librte_mbuf/rte_mbuf.h
> @@ -1468,9 +1468,11 @@ static inline void rte_pktmbuf_attach(struct rte_mbuf *mi, struct rte_mbuf *m)
>   */
>  static inline void rte_pktmbuf_detach(struct rte_mbuf *m)
>  {
> +	struct rte_mbuf *md = rte_mbuf_from_indirect(m);
>  	struct rte_mempool *mp = m->pool;
>  	uint32_t mbuf_size, buf_len, priv_size;
> 
> +	rte_mbuf_refcnt_update(md, -1);
>  	priv_size = rte_pktmbuf_priv_size(mp);
>  	mbuf_size = sizeof(struct rte_mbuf) + priv_size;
>  	buf_len = rte_pktmbuf_data_room_size(mp);
> @@ -1498,7 +1500,7 @@ __rte_pktmbuf_prefree_seg(struct rte_mbuf *m)
>  		if (RTE_MBUF_INDIRECT(m)) {
>  			struct rte_mbuf *md = rte_mbuf_from_indirect(m);
>  			rte_pktmbuf_detach(m);
> -			if (rte_mbuf_refcnt_update(md, -1) == 0)
> +			if (rte_mbuf_refcnt_read(md) == 0)
>  				__rte_mbuf_raw_free(md);
>  		}
>  		return m;
> --
> 1.9.1