Re: [dpdk-dev] [PATCH] net/af_xdp: free mbuf when allocate Tx queue fails

From: David Marchand <david.marchand@redhat.com>
To: Xiaolong Ye <xiaolong.ye@intel.com>
Cc: dev <dev@dpdk.org>, Ferruh Yigit <ferruh.yigit@intel.com>,
	 Qi Zhang <qi.z.zhang@intel.com>,
	Karlsson Magnus <magnus.karlsson@intel.com>,
	 Topel Bjorn <bjorn.topel@intel.com>
Subject: Re: [dpdk-dev] [PATCH] net/af_xdp: free mbuf when allocate Tx queue fails
Date: Tue, 9 Apr 2019 10:34:59 +0200	[thread overview]
Message-ID: <CAJFAV8yNEPDi2SmAbccbOgQBee_WPC3D7qZwoo=81VK-j9zpFQ@mail.gmail.com> (raw)
In-Reply-To: <20190409082128.33896-1-xiaolong.ye@intel.com>

On Tue, Apr 9, 2019 at 10:27 AM Xiaolong Ye <xiaolong.ye@intel.com> wrote:

> When we fail to allocate enough slots in tx queue for transmitting
> packets, we need to free the corresponding mbufs.
>

You'd better let the application retry on its own...

> Fixes: f1debd77efaf ("net/af_xdp: introduce AF_XDP PMD")
>
> Signed-off-by: Xiaolong Ye <xiaolong.ye@intel.com>
> ---
>  drivers/net/af_xdp/rte_eth_af_xdp.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c
> b/drivers/net/af_xdp/rte_eth_af_xdp.c
> index 007a1c6b4..bc7973b56 100644
> --- a/drivers/net/af_xdp/rte_eth_af_xdp.c
> +++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
> @@ -276,7 +276,8 @@ eth_af_xdp_tx(void *queue, struct rte_mbuf **bufs,
> uint16_t nb_pkts)
>
>         if (xsk_ring_prod__reserve(&txq->tx, nb_pkts, &idx_tx) != nb_pkts)
> {
>                 kick_tx(txq);
> -               return 0;
> +               nb_pkts = 0;
> +               goto out;
>

...and free back the buffers you got from the umem ring here.

        }
>
>         for (i = 0; i < nb_pkts; i++) {
>

-- 
David Marchand