From: Tariq Toukan <ttoukan.linux@gmail.com>
To: Saeed Mahameed <saeedm@dev.mellanox.co.il>,
Brenden Blanco <bblanco@plumgrid.com>
Cc: "David S. Miller" <davem@davemloft.net>,
Linux Netdev List <netdev@vger.kernel.org>,
Martin KaFai Lau <kafai@fb.com>,
Jesper Dangaard Brouer <brouer@redhat.com>,
Ari Saha <as754m@att.com>,
Alexei Starovoitov <alexei.starovoitov@gmail.com>,
Or Gerlitz <gerlitz.or@gmail.com>,
john fastabend <john.fastabend@gmail.com>,
hannes@stressinduktion.org, Thomas Graf <tgraf@suug.ch>,
Tom Herbert <tom@herbertland.com>,
Daniel Borkmann <daniel@iogearbox.net>
Subject: Re: [PATCH v6 04/12] net/mlx4_en: add support for fast rx drop bpf program
Date: Sun, 10 Jul 2016 18:25:40 +0300 [thread overview]
Message-ID: <57d2eb82-1992-b6fb-0727-b3b0d8983765@gmail.com> (raw)
In-Reply-To: <CALzJLG8+LzX_sELAC-TVszeWXZFbCKVJ+rJnDT50fqN5PodEAA@mail.gmail.com>
On 09/07/2016 10:58 PM, Saeed Mahameed wrote:
> On Fri, Jul 8, 2016 at 5:15 AM, Brenden Blanco <bblanco@plumgrid.com> wrote:
>> + /* A bpf program gets first chance to drop the packet. It may
>> + * read bytes but not past the end of the frag.
>> + */
>> + if (prog) {
>> + struct xdp_buff xdp;
>> + dma_addr_t dma;
>> + u32 act;
>> +
>> + dma = be64_to_cpu(rx_desc->data[0].addr);
>> + dma_sync_single_for_cpu(priv->ddev, dma,
>> + priv->frag_info[0].frag_size,
>> + DMA_FROM_DEVICE);
> In case of XDP_PASS we will dma_sync again in the normal path, this
> can be improved by doing the dma_sync as soon as we can and once and
> for all, regardless of the path the packet is going to take
> (XDP_DROP/mlx4_en_complete_rx_desc/mlx4_en_rx_skb).
I agree with Saeed, dma_sync is a heavy operation that is now done twice
for all packets with XDP_PASS.
We should try our best to avoid performance degradation in the flow of
unfiltered packets.
Regards,
Tariq
next prev parent reply other threads:[~2016-07-10 15:25 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-08 2:15 [PATCH v6 00/12] Add driver bpf hook for early packet drop and forwarding Brenden Blanco
2016-07-08 2:15 ` [PATCH v6 01/12] bpf: add XDP prog type for early driver filter Brenden Blanco
2016-07-09 8:14 ` Jesper Dangaard Brouer
2016-07-09 13:47 ` Tom Herbert
2016-07-10 13:37 ` Jesper Dangaard Brouer
2016-07-10 17:09 ` Brenden Blanco
2016-07-10 20:30 ` Tom Herbert
2016-07-11 10:15 ` Daniel Borkmann
2016-07-11 12:58 ` Jesper Dangaard Brouer
2016-07-10 20:27 ` Tom Herbert
2016-07-11 11:36 ` Jesper Dangaard Brouer
2016-07-10 20:56 ` Tom Herbert
2016-07-11 16:51 ` Brenden Blanco
2016-07-11 21:21 ` Daniel Borkmann
2016-07-10 21:04 ` Tom Herbert
2016-07-11 13:53 ` Jesper Dangaard Brouer
2016-07-08 2:15 ` [PATCH v6 02/12] net: add ndo to set xdp prog in adapter rx Brenden Blanco
2016-07-10 20:59 ` Tom Herbert
2016-07-11 10:35 ` Daniel Borkmann
2016-07-08 2:15 ` [PATCH v6 03/12] rtnl: add option for setting link xdp prog Brenden Blanco
2016-07-08 2:15 ` [PATCH v6 04/12] net/mlx4_en: add support for fast rx drop bpf program Brenden Blanco
2016-07-09 14:07 ` Or Gerlitz
2016-07-10 15:40 ` Brenden Blanco
2016-07-10 16:38 ` Tariq Toukan
2016-07-09 19:58 ` Saeed Mahameed
2016-07-09 21:37 ` Or Gerlitz
2016-07-10 15:25 ` Tariq Toukan [this message]
2016-07-10 16:05 ` Brenden Blanco
2016-07-11 11:48 ` Saeed Mahameed
2016-07-11 21:49 ` Brenden Blanco
2016-07-08 2:15 ` [PATCH v6 05/12] Add sample for adding simple drop program to link Brenden Blanco
2016-07-09 20:21 ` Saeed Mahameed
2016-07-11 11:09 ` Jamal Hadi Salim
2016-07-11 13:37 ` Jesper Dangaard Brouer
2016-07-16 14:55 ` Jamal Hadi Salim
2016-07-08 2:15 ` [PATCH v6 06/12] net/mlx4_en: add page recycle to prepare rx ring for tx support Brenden Blanco
2016-07-08 2:15 ` [PATCH v6 07/12] bpf: add XDP_TX xdp_action for direct forwarding Brenden Blanco
2016-07-08 2:15 ` [PATCH v6 08/12] net/mlx4_en: break out tx_desc write into separate function Brenden Blanco
2016-07-08 2:15 ` [PATCH v6 09/12] net/mlx4_en: add xdp forwarding and data write support Brenden Blanco
2016-07-08 2:15 ` [PATCH v6 10/12] bpf: enable direct packet data write for xdp progs Brenden Blanco
2016-07-08 2:15 ` [PATCH v6 11/12] bpf: add sample for xdp forwarding and rewrite Brenden Blanco
2016-07-08 2:15 ` [PATCH v6 12/12] net/mlx4_en: add prefetch in xdp rx path Brenden Blanco
2016-07-08 3:56 ` Eric Dumazet
2016-07-08 4:16 ` Alexei Starovoitov
2016-07-08 6:56 ` Eric Dumazet
2016-07-08 16:49 ` Brenden Blanco
2016-07-10 20:48 ` Tom Herbert
2016-07-10 20:50 ` Tom Herbert
2016-07-11 14:54 ` Jesper Dangaard Brouer
2016-07-08 15:20 ` Jesper Dangaard Brouer
2016-07-08 16:02 ` [net-next PATCH RFC] mlx4: RX prefetch loop Jesper Dangaard Brouer
2016-07-11 11:09 ` Jesper Dangaard Brouer
2016-07-11 16:00 ` Brenden Blanco
2016-07-11 23:05 ` Alexei Starovoitov
2016-07-12 12:45 ` Jesper Dangaard Brouer
2016-07-12 16:46 ` Alexander Duyck
2016-07-12 19:52 ` Jesper Dangaard Brouer
2016-07-13 1:37 ` Alexei Starovoitov
2016-07-10 16:14 ` [PATCH v6 00/12] Add driver bpf hook for early packet drop and forwarding Tariq Toukan
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