public inbox for [email protected]
 help / color / mirror / Atom feed
From: David Ahern <[email protected]>
To: Pavel Begunkov <[email protected]>,
	[email protected], [email protected],
	[email protected]
Cc: "David S . Miller" <[email protected]>,
	Jakub Kicinski <[email protected]>,
	Jonathan Lemon <[email protected]>,
	Willem de Bruijn <[email protected]>,
	Jens Axboe <[email protected]>,
	[email protected]
Subject: Re: [PATCH net-next v4 11/27] tcp: support externally provided ubufs
Date: Thu, 7 Jul 2022 22:06:54 -0600	[thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <7ee05f644e3b3626b693973738364bcb23cf905d.1657194434.git.asml.silence@gmail.com>

On 7/7/22 5:49 AM, Pavel Begunkov wrote:
> Teach ipv4/udp how to use external ubuf_info provided in msghdr and

ipv4/tcp?

> also prepare it for managed frags by sprinkling
> skb_zcopy_downgrade_managed() when it could mix managed and not managed
> frags.
> 
> Signed-off-by: Pavel Begunkov <[email protected]>
> ---
>  net/ipv4/tcp.c | 32 ++++++++++++++++++++------------
>  1 file changed, 20 insertions(+), 12 deletions(-)
> 
> diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
> index 390eb3dc53bd..a81f694af5e9 100644
> --- a/net/ipv4/tcp.c
> +++ b/net/ipv4/tcp.c
> @@ -1223,17 +1223,23 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
>  
>  	flags = msg->msg_flags;
>  
> -	if (flags & MSG_ZEROCOPY && size && sock_flag(sk, SOCK_ZEROCOPY)) {
> +	if ((flags & MSG_ZEROCOPY) && size) {
>  		skb = tcp_write_queue_tail(sk);
> -		uarg = msg_zerocopy_realloc(sk, size, skb_zcopy(skb));
> -		if (!uarg) {
> -			err = -ENOBUFS;
> -			goto out_err;
> -		}
>  
> -		zc = sk->sk_route_caps & NETIF_F_SG;
> -		if (!zc)
> -			uarg->zerocopy = 0;
> +		if (msg->msg_ubuf) {
> +			uarg = msg->msg_ubuf;
> +			net_zcopy_get(uarg);
> +			zc = sk->sk_route_caps & NETIF_F_SG;
> +		} else if (sock_flag(sk, SOCK_ZEROCOPY)) {
> +			uarg = msg_zerocopy_realloc(sk, size, skb_zcopy(skb));
> +			if (!uarg) {
> +				err = -ENOBUFS;
> +				goto out_err;
> +			}
> +			zc = sk->sk_route_caps & NETIF_F_SG;
> +			if (!zc)
> +				uarg->zerocopy = 0;
> +		}
>  	}
>  
>  	if (unlikely(flags & MSG_FASTOPEN || inet_sk(sk)->defer_connect) &&
> @@ -1356,9 +1362,11 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
>  
>  			copy = min_t(int, copy, pfrag->size - pfrag->offset);
>  
> -			if (tcp_downgrade_zcopy_pure(sk, skb))
> -				goto wait_for_space;
> -
> +			if (unlikely(skb_zcopy_pure(skb) || skb_zcopy_managed(skb))) {
> +				if (tcp_downgrade_zcopy_pure(sk, skb))
> +					goto wait_for_space;
> +				skb_zcopy_downgrade_managed(skb);
> +			}
>  			copy = tcp_wmem_schedule(sk, copy);
>  			if (!copy)
>  				goto wait_for_space;

You dropped the msg->msg_ubuf checks on jump labels. Removing the one
you had at 'out_nopush' I agree with based on my tests (i.e, it is not
needed).

The one at 'out_err' seems like it is needed - but it has been a few
weeks since I debugged that case. I believe the error path I was hitting
was sk_stream_wait_memory with MSG_DONTWAIT flag set meaning timeout is
0 and it jumps there with EPIPE.



  reply	other threads:[~2022-07-08  4:07 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-07-07 11:49 [PATCH net-next v4 00/27] io_uring zerocopy send Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 01/27] ipv4: avoid partial copy for zc Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 02/27] ipv6: " Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 03/27] skbuff: don't mix ubuf_info from different sources Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 04/27] skbuff: add SKBFL_DONT_ORPHAN flag Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 05/27] skbuff: carry external ubuf_info in msghdr Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 06/27] net: Allow custom iter handler " Pavel Begunkov
2022-07-11 12:20   ` Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 07/27] net: introduce managed frags infrastructure Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 08/27] net: introduce __skb_fill_page_desc_noacc Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 09/27] ipv4/udp: support externally provided ubufs Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 10/27] ipv6/udp: " Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 11/27] tcp: " Pavel Begunkov
2022-07-08  4:06   ` David Ahern [this message]
2022-07-08 14:03     ` Pavel Begunkov
2022-07-13 23:38       ` David Ahern
2022-07-07 11:49 ` [PATCH net-next v4 12/27] io_uring: initialise msghdr::msg_ubuf Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 13/27] io_uring: export io_put_task() Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 14/27] io_uring: add zc notification infrastructure Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 15/27] io_uring: cache struct io_notif Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 16/27] io_uring: complete notifiers in tw Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 17/27] io_uring: add rsrc referencing for notifiers Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 18/27] io_uring: add notification slot registration Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 19/27] io_uring: wire send zc request type Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 20/27] io_uring: account locked pages for non-fixed zc Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 21/27] io_uring: allow to pass addr into sendzc Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 22/27] io_uring: sendzc with fixed buffers Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 23/27] io_uring: flush notifiers after sendzc Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 24/27] io_uring: rename IORING_OP_FILES_UPDATE Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 25/27] io_uring: add zc notification flush requests Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 26/27] io_uring: enable managed frags with register buffers Pavel Begunkov
2022-07-07 11:49 ` [PATCH net-next v4 27/27] selftests/io_uring: test zerocopy send Pavel Begunkov
2022-07-08  4:10 ` [PATCH net-next v4 00/27] io_uring " David Ahern
2022-07-08 14:26   ` Pavel Begunkov
2022-07-11 12:56     ` Pavel Begunkov
2022-07-13 23:45       ` David Ahern
2022-07-14 18:55         ` Pavel Begunkov
2022-07-18  2:19           ` David Ahern
2022-07-20 13:32             ` Pavel Begunkov
2022-07-24 18:28             ` David Ahern
2022-07-27 10:51               ` Pavel Begunkov
2022-07-29 22:30                 ` David Ahern
2022-09-26 20:08               ` Pavel Begunkov
2022-09-28 19:31                 ` David Ahern
2022-09-28 20:11                   ` Pavel Begunkov

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox