From: Eric Dumazet <eric.dumazet@gmail.com>
To: Tom Herbert <therbert@google.com>
Cc: Linux Netdev List <netdev@vger.kernel.org>,
David Miller <davem@davemloft.net>
Subject: Re: Bug in computing data_len in tcp_sendmsg?
Date: Thu, 01 Dec 2011 10:15:37 +0100 [thread overview]
Message-ID: <1322730937.2335.6.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC> (raw)
In-Reply-To: <CA+mtBx9fE0qQc-LndM03ykhVMV5n9Z4KHcD6PpTiy=M79GOnKw@mail.gmail.com>
Le mercredi 30 novembre 2011 à 21:09 -0800, Tom Herbert a écrit :
> > Or the "bug" was to assume that skb was headless.
> > It was true until recently.
> >
> > We recently added commit f07d960df33c5aef
> > (tcp: avoid frag allocation for small frames)
> >
> > to avoid page allocation for small frames.
> >
> > So now, skb can contain in head part of tcp data.
>
> Yes, reverting that patch seems to fix the problem. Eric, do you have
> an idea what should be used to determine length of headers in an skb
> now (mac through transport).
I dont know why its even necessary :
TSO enabled NIC all provide hardware counters, so why even bother
computing tx_bytes ourself ?
skb->len is appropriate for BQL, as long as producers/consumer use the
same skb->len. 1 or 2% error is not a problem if not cumulative ?
next prev parent reply other threads:[~2011-12-01 9:15 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-01 1:48 Bug in computing data_len in tcp_sendmsg? Tom Herbert
2011-12-01 3:42 ` Eric Dumazet
2011-12-01 4:06 ` Tom Herbert
2011-12-01 4:16 ` David Miller
2011-12-01 4:17 ` Eric Dumazet
2011-12-01 5:09 ` Tom Herbert
2011-12-01 9:15 ` Eric Dumazet [this message]
2011-12-01 17:29 ` Jesse Brandeburg
2011-12-01 18:04 ` David Miller
2011-12-01 20:37 ` Eric Dumazet
2011-12-01 22:18 ` Vijay Subramanian
2011-12-01 22:30 ` Eric Dumazet
2011-12-02 6:18 ` Vijay Subramanian
2011-12-02 11:59 ` Eric Dumazet
2011-12-02 15:44 ` Eric Dumazet
2011-12-02 16:05 ` Eric Dumazet
2011-12-02 18:13 ` David Miller
2011-12-02 18:36 ` Eric Dumazet
2011-12-02 18:40 ` David Miller
2011-12-02 20:22 ` Eric Dumazet
2011-12-02 20:24 ` David Miller
2011-12-02 20:45 ` Eric Dumazet
2011-12-02 20:48 ` Eric Dumazet
2011-12-02 21:30 ` David Miller
2011-12-03 15:09 ` Eric Dumazet
2011-12-04 7:39 ` [PATCH] tcp: take care of misalignments Eric Dumazet
2011-12-04 18:21 ` David Miller
2011-12-04 18:51 ` Eric Dumazet
2011-12-05 23:45 ` David Miller
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=1322730937.2335.6.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC \
--to=eric.dumazet@gmail.com \
--cc=davem@davemloft.net \
--cc=netdev@vger.kernel.org \
--cc=therbert@google.com \
/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