From: Pavel Begunkov <asml.silence@gmail.com>
To: netdev@vger.kernel.org, "David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>, Wei Liu <wei.liu@kernel.org>,
Paul Durrant <paul@xen.org>,
Pavel Begunkov <asml.silence@gmail.com>
Subject: [PATCH net-next 17/27] tcp: optimise skb_zerocopy_iter_stream()
Date: Sun, 3 Apr 2022 14:06:29 +0100 [thread overview]
Message-ID: <0c14446e83b09759c08d9ab12b747e80508de74b.1648981571.git.asml.silence@gmail.com> (raw)
In-Reply-To: <cover.1648981570.git.asml.silence@gmail.com>
It's expensive to make a copy of 40B struct iov_iter to the point it
was taking 0.2-0.5% of all cycles in my tests. iov_iter_revert() should
be fine as it's a simple case without nested reverts/truncates.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
net/core/skbuff.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 65ac779eb5cd..77cbdb02e885 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1343,7 +1343,6 @@ int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb,
struct msghdr *msg, int len,
struct ubuf_info *uarg)
{
- struct iov_iter orig_iter = msg->msg_iter;
int err, orig_len = skb->len;
/* An skb can only point to one uarg. This edge case happens when
@@ -1357,7 +1356,7 @@ int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb,
struct sock *save_sk = skb->sk;
/* Streams do not free skb on error. Reset to prev state. */
- msg->msg_iter = orig_iter;
+ iov_iter_revert(&msg->msg_iter, skb->len - orig_len);
skb->sk = sk;
___pskb_trim(skb, orig_len);
skb->sk = save_sk;
--
2.35.1
next prev parent reply other threads:[~2022-04-03 13:08 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-03 13:06 [RFC net-next 00/27] net and/or udp optimisations Pavel Begunkov
2022-04-03 13:06 ` [PATCH net-next 01/27] sock: deduplicate ->sk_wmem_alloc check Pavel Begunkov
2022-04-03 13:06 ` [PATCH net-next 02/27] sock: optimise sock_def_write_space send refcounting Pavel Begunkov
2022-04-03 13:06 ` [PATCH net-next 03/27] sock: optimise sock_def_write_space barriers Pavel Begunkov
2022-04-03 13:06 ` [PATCH net-next 04/27] skbuff: drop zero check from skb_zcopy_set Pavel Begunkov
2022-04-03 13:06 ` [PATCH net-next 05/27] skbuff: drop null check from skb_zcopy Pavel Begunkov
2022-04-03 13:06 ` [PATCH net-next 06/27] net: xen: set zc flags only when there is ubuf Pavel Begunkov
2022-04-03 13:06 ` [PATCH net-next 07/27] skbuff: introduce skb_is_zcopy() Pavel Begunkov
2022-04-03 13:06 ` [PATCH net-next 08/27] skbuff: optimise alloc_skb_with_frags() Pavel Begunkov
2022-04-03 13:06 ` [PATCH net-next 09/27] net: inline sock_alloc_send_skb Pavel Begunkov
2022-04-03 13:06 ` [PATCH net-next 10/27] net: inline part of skb_csum_hwoffload_help Pavel Begunkov
2022-04-03 13:06 ` [PATCH net-next 11/27] net: inline skb_zerocopy_iter_dgram Pavel Begunkov
2022-04-03 13:06 ` [PATCH net-next 12/27] ipv6: inline ip6_local_out() Pavel Begunkov
2022-04-03 13:06 ` [PATCH net-next 13/27] ipv6: help __ip6_finish_output() inlining Pavel Begunkov
2022-04-03 13:06 ` [PATCH net-next 14/27] ipv6: refactor ip6_finish_output2() Pavel Begunkov
2022-04-03 13:06 ` [PATCH net-next 15/27] net: inline dev_queue_xmit() Pavel Begunkov
2022-04-03 13:06 ` [PATCH net-next 16/27] ipv6: partially inline fl6_update_dst() Pavel Begunkov
2022-04-03 13:06 ` Pavel Begunkov [this message]
2022-04-03 13:06 ` [PATCH net-next 18/27] net: optimise ipcm6 cookie init Pavel Begunkov
2022-04-03 13:06 ` [PATCH net-next 19/27] udp/ipv6: refactor udpv6_sendmsg udplite checks Pavel Begunkov
2022-04-03 13:06 ` [PATCH net-next 20/27] udp/ipv6: move pending section of udpv6_sendmsg Pavel Begunkov
2022-04-03 13:06 ` [PATCH net-next 21/27] udp/ipv6: prioritise the ip6 path over ip4 checks Pavel Begunkov
2022-04-03 13:06 ` [PATCH net-next 22/27] udp/ipv6: optimise udpv6_sendmsg() daddr checks Pavel Begunkov
2022-04-03 13:06 ` [PATCH net-next 23/27] udp/ipv6: optimise out daddr reassignment Pavel Begunkov
2022-04-03 13:06 ` [PATCH net-next 24/27] udp/ipv6: clean up udpv6_sendmsg's saddr init Pavel Begunkov
2022-04-03 13:06 ` [PATCH net-next 25/27] ipv6: refactor opts push in __ip6_make_skb() Pavel Begunkov
2022-04-03 13:06 ` [PATCH net-next 26/27] ipv6: improve opt-less __ip6_make_skb() Pavel Begunkov
2022-04-03 13:06 ` [PATCH net-next 27/27] ipv6: clean up ip6_setup_cork Pavel Begunkov
2022-04-06 9:44 ` [RFC net-next 00/27] net and/or udp optimisations Eric Dumazet
2022-04-11 12:04 ` 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 \
--in-reply-to=0c14446e83b09759c08d9ab12b747e80508de74b.1648981571.git.asml.silence@gmail.com \
--to=asml.silence@gmail.com \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=kuba@kernel.org \
--cc=netdev@vger.kernel.org \
--cc=paul@xen.org \
--cc=wei.liu@kernel.org \
/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;
as well as URLs for NNTP newsgroup(s).