netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: David Miller <davem@davemloft.net>
To: netdev@vger.kernel.org
Subject: small RPS cache for fragments?
Date: Tue, 17 May 2011 14:33:42 -0400 (EDT)	[thread overview]
Message-ID: <20110517.143342.1566027350038182221.davem@davemloft.net> (raw)


It seems to me that we can solve the UDP fragmentation problem for
flow steering very simply by creating a (saddr/daddr/IPID) entry in a
table that maps to the corresponding RPS flow entry.

When we see the initial frag with the UDP header, we create the
saddr/daddr/IPID mapping, and we tear it down when we hit the
saddr/daddr/IPID mapping and the packet has the IP_MF bit clear.

We only inspect the saddr/daddr/IPID cache when iph->frag_off is
non-zero.

It's best effort and should work quite well.

Even a one-behind cache, per-NAPI instance, would do a lot better than
what happens at the moment.  Especially since the IP fragments mostly
arrive as one packet train.

             reply	other threads:[~2011-05-17 18:33 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-05-17 18:33 David Miller [this message]
2011-05-17 20:02 ` small RPS cache for fragments? Tom Herbert
2011-05-17 20:17   ` Rick Jones
2011-05-17 20:41     ` Rick Jones
2011-05-17 20:49   ` David Miller
2011-05-17 21:00     ` Eric Dumazet
2011-05-17 21:10       ` David Miller
2011-05-17 21:13         ` Rick Jones
2011-05-17 21:13         ` Ben Hutchings
2011-05-17 21:26           ` David Miller
2011-05-17 21:40             ` Rick Jones
2011-05-17 21:27           ` Eric Dumazet
2011-05-17 21:11       ` Rick Jones
2011-05-17 21:11       ` Ben Hutchings
2011-05-17 21:27     ` Tom Herbert
2011-05-17 21:28       ` David Miller
2011-05-17 23:59     ` Changli Gao
2011-05-18  6:37       ` David Miller
2011-05-17 20:14 ` Eric Dumazet
2011-05-17 20:47   ` David Miller
2011-05-17 21:44   ` Andi Kleen
2011-05-17 21:52     ` Eric Dumazet
2011-05-17 22:03       ` Andi Kleen
2011-05-17 21:44 ` David Miller
2011-05-17 21:48   ` Andi Kleen
2011-05-17 21:50     ` David Miller
2011-05-17 22:06       ` Andi Kleen
2011-05-17 22:42       ` Rick Jones
2011-05-24 20:01 ` David Miller
2011-05-24 21:38   ` Rick Jones
2011-06-04 20:29     ` David Miller
2011-06-06 17:08       ` Rick Jones
2011-06-06 17:15         ` Eric Dumazet
2011-06-06 18:06           ` Rick Jones
2011-06-06 19:23           ` David Miller
2011-06-06 19:22         ` David Miller
2011-06-06 20:05           ` Rick Jones
2011-06-06 21:06             ` Jay Vosburgh
2011-06-06 21:40               ` David Miller
2011-06-06 22:49                 ` Chris Friesen

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=20110517.143342.1566027350038182221.davem@davemloft.net \
    --to=davem@davemloft.net \
    --cc=netdev@vger.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).