From: David Ahern <dsahern@gmail.com>
To: Pavel Begunkov <asml.silence@gmail.com>,
io-uring@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Cc: Jakub Kicinski <kuba@kernel.org>,
Jonathan Lemon <jonathan.lemon@gmail.com>,
"David S . Miller" <davem@davemloft.net>,
Willem de Bruijn <willemb@google.com>,
Eric Dumazet <edumazet@google.com>,
Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
David Ahern <dsahern@kernel.org>, Jens Axboe <axboe@kernel.dk>
Subject: Re: [RFC 00/12] io_uring zerocopy send
Date: Wed, 1 Dec 2021 12:20:56 -0700 [thread overview]
Message-ID: <0b92f046-5ac3-7138-2775-59fadee6e17a@gmail.com> (raw)
In-Reply-To: <889c0306-afed-62cd-d95b-a20b8e798979@gmail.com>
On 12/1/21 12:11 PM, Pavel Begunkov wrote:
> btw, why a dummy device would ever go through loopback? It doesn't
> seem to make sense, though may be missing something.
You are sending to a local ip address, so the fib_lookup returns
RTN_LOCAL. The code makes dev_out the loopback:
https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/tree/net/ipv4/route.c#n2773
(you are not using vrf so ignore the l3mdev reference). loopback device
has the logic to put the skb back in the stack for Rx processing:
https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/tree/drivers/net/loopback.c#n68
next prev parent reply other threads:[~2021-12-01 19:21 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-30 15:18 Pavel Begunkov
2021-11-30 15:18 ` [RFC 01/12] skbuff: add SKBFL_DONT_ORPHAN flag Pavel Begunkov
2021-11-30 15:18 ` [RFC 02/12] skbuff: pass a struct ubuf_info in msghdr Pavel Begunkov
2021-11-30 15:18 ` [RFC 03/12] net/udp: add support msgdr::msg_ubuf Pavel Begunkov
2021-11-30 15:18 ` [RFC 04/12] net: add zerocopy_sg_from_iter for bvec Pavel Begunkov
2021-11-30 15:18 ` [RFC 05/12] net: optimise page get/free for bvec zc Pavel Begunkov
2021-12-01 19:20 ` Jonathan Lemon
2021-12-01 20:17 ` Pavel Begunkov
2021-11-30 15:18 ` [RFC 06/12] io_uring: add send notifiers registration Pavel Begunkov
2021-11-30 15:18 ` [RFC 07/12] io_uring: infrastructure for send zc notifications Pavel Begunkov
2021-11-30 15:18 ` [RFC 08/12] io_uring: wire send zc request type Pavel Begunkov
2021-11-30 15:18 ` [RFC 09/12] io_uring: add an option to flush zc notifications Pavel Begunkov
2021-11-30 15:18 ` [RFC 10/12] io_uring: opcode independent fixed buf import Pavel Begunkov
2021-11-30 15:18 ` [RFC 11/12] io_uring: sendzc with fixed buffers Pavel Begunkov
2021-11-30 15:19 ` [RFC 12/12] io_uring: cache struct ubuf_info Pavel Begunkov
2021-12-01 3:10 ` [RFC 00/12] io_uring zerocopy send David Ahern
2021-12-01 15:32 ` Pavel Begunkov
2021-12-01 17:57 ` David Ahern
2021-12-01 19:11 ` Pavel Begunkov
2021-12-01 19:20 ` David Ahern [this message]
2021-12-01 20:15 ` Pavel Begunkov
2021-12-01 21:51 ` Martin KaFai Lau
2021-12-01 22:35 ` David Ahern
2021-12-01 23:07 ` Martin KaFai Lau
2021-12-01 23:18 ` Pavel Begunkov
2021-12-02 15:48 ` Pavel Begunkov
2021-12-02 17:40 ` Martin KaFai Lau
2021-12-01 20:42 ` Pavel Begunkov
2021-12-01 14:31 ` Pavel Begunkov
2021-12-01 17:49 ` David Ahern
2021-12-01 19:59 ` Pavel Begunkov
2021-12-01 18:10 ` Willem de Bruijn
2021-12-01 19:59 ` Pavel Begunkov
2021-12-01 20:29 ` Pavel Begunkov
2021-12-02 0:36 ` Willem de Bruijn
2021-12-02 16:25 ` Pavel Begunkov
2021-12-02 0:32 ` Willem de Bruijn
2021-12-02 16:45 ` Pavel Begunkov
2021-12-02 21:25 ` Willem de Bruijn
2021-12-03 16:19 ` Pavel Begunkov
2021-12-03 16:30 ` Willem de Bruijn
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