[dpdk-dev] [PATCH v2] example/ipv4_multicast: fix app hanging when using clone

[Ananyev, Konstantin]

Hi Dong,

> Hi Herakliusz,
> 
> Since pkt->ol_flags might set some other bits except IND_ATTACHED_MBUF, how about set its value to original pkt->ol_flag

It could be done, but not sure what is the point?
Which flags you think we need to copy from cloned mbuf (segment #2) to new header?
Konstantin

> 
> Regards,
> Dong
> 
> -----Original Message-----
> From: Lipiec, Herakliusz
> Sent: Tuesday, November 13, 2018 19:49
> To: dev at dpdk.org
> Cc: Ananyev, Konstantin <konstantin.ananyev at intel.com>; Wang, Dong1 <dong1.wang at intel.com>; thomas at monjalon.net; Burakov,
> Anatoly <anatoly.burakov at intel.com>; Lipiec, Herakliusz <herakliusz.lipiec at intel.com>; stable at dpdk.org
> Subject: [PATCH v2] example/ipv4_multicast: fix app hanging when using clone
> 
> The ipv4_multicast sample application was dropping packets when using mbuf clone. When creating an L2 header and copying metadata
> from the source packet, the ol_flags were also copied along with all the other metadata. Because the cloned packet had
> IND_ATTACHED_MBUF flag set in its ol_flags, this caused the packets to never be freed when using rte_pktmbuf_free.
> Since copying ol_flags from the cloned packet is not necessary in the first place, just don't do it.
> 
> Fixes: af75078fece3 ("first public release")
> CC: stable at dpdk.org
> 
> Reported-by: Wang Dong <dong1.wang at intel.com>
> Signed-off-by: Herakliusz Lipiec <herakliusz.lipiec at intel.com>
> ---
>  doc/guides/sample_app_ug/ipv4_multicast.rst | 1 -
>  examples/ipv4_multicast/main.c              | 2 --
>  2 files changed, 3 deletions(-)
> 
> diff --git a/doc/guides/sample_app_ug/ipv4_multicast.rst b/doc/guides/sample_app_ug/ipv4_multicast.rst
> index ce1474ec7..f6efa7f6f 100644
> --- a/doc/guides/sample_app_ug/ipv4_multicast.rst
> +++ b/doc/guides/sample_app_ug/ipv4_multicast.rst
> @@ -319,7 +319,6 @@ It is the mcast_out_pkt() function that performs the packet duplication (either
>          hdr->pkt.in_port = pkt->pkt.in_port;
>          hdr->pkt.vlan_macip = pkt->pkt.vlan_macip;
>          hdr->pkt.hash = pkt->pkt.hash;
> -        hdr->ol_flags = pkt->ol_flags;
>          rte_mbuf_sanity_check(hdr, RTE_MBUF_PKT, 1);
> 
>          return hdr;
> diff --git a/examples/ipv4_multicast/main.c b/examples/ipv4_multicast/main.c index 4073a4907..428ca4694 100644
> --- a/examples/ipv4_multicast/main.c
> +++ b/examples/ipv4_multicast/main.c
> @@ -266,8 +266,6 @@ mcast_out_pkt(struct rte_mbuf *pkt, int use_clone)
>  	hdr->tx_offload = pkt->tx_offload;
>  	hdr->hash = pkt->hash;
> 
> -	hdr->ol_flags = pkt->ol_flags;
> -
>  	__rte_mbuf_sanity_check(hdr, 1);
>  	return hdr;
>  }
> --
> 2.17.1