Netdev List
 help / color / mirror / Atom feed
From: Eric Dumazet <eric.dumazet@gmail.com>
To: Simon Kirby <sim@hostway.ca>
Cc: Simon Horman <horms@verge.net.au>, netdev@vger.kernel.org
Subject: Re: TSO/GRO/LRO/somethingO breaks LVS on 2.6.36
Date: Thu, 09 Dec 2010 03:51:59 +0100	[thread overview]
Message-ID: <1291863119.2795.29.camel@edumazet-laptop> (raw)
In-Reply-To: <20101209023509.GA21216@hostway.ca>

Le mercredi 08 décembre 2010 à 18:35 -0800, Simon Kirby a écrit :

> Right.  So, on 2.6.35, ethtool shows:
> 
> # ethtool -k eth1
> Offload parameters for eth1:
> rx-checksumming: on
> tx-checksumming: on
> scatter-gather: on
> tcp segmentation offload: on
> udp fragmentation offload: off
> generic segmentation offload: on
> large receive offload: off
> 
> # ethtool -k eth1.39
> Offload parameters for eth1.39:
> rx-checksumming: on
> tx-checksumming: off
> scatter-gather: off
> tcp segmentation offload: off
> udp fragmentation offload: off
> generic segmentation offload: off
> large receive offload: off
> 
> On 2.6.36, ethtool shows:
> 
> # ethtool -k eth1
> Offload parameters for eth1:
> rx-checksumming: on
> tx-checksumming: on
> scatter-gather: on
> tcp segmentation offload: on
> udp fragmentation offload: off
> generic segmentation offload: on
> large receive offload: off
> 
> # ethtool -k eth1.39
> Offload parameters for eth1.39:
> rx-checksumming: on
> tx-checksumming: on
> scatter-gather: on
> tcp segmentation offload: on
> udp fragmentation offload: off
> generic segmentation offload: on
> large receive offload: off
> 
> And if I set it with ethtool -K eth1.39 gso off; ethtool -K eth1 gso off,
> it says "off", but I still see merged frames, as verified with an nc <
> /dev/zero and tcpdump -i any -n 'length > 1500'.
> 


Yep, but you also have "tso on" by default on 2.6.36 and eth1.39 (vlan)

> > I will prepare a backport of the "ipvs: allow transmit of GRO aggregated
> > skbs" patch to v2.6.36 and post it shortly.  Testing to see if that
> > resolves the problem that you are seeing would probably be a good start.
> 
> I can test this in our case, and it should specifically work on the
> servers we were seeing the problem on, but it still needs some
> complicated logic to be safe for all cases (like when LVS decides to
> route out an interface without GRO).  Anyway, thanks!
> 
> Simon-



  reply	other threads:[~2010-12-09  2:52 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-12-03 10:34 TSO/GRO/LRO/somethingO breaks LVS on 2.6.36 Simon Kirby
2010-12-03 11:29 ` Eric Dumazet
2010-12-03 12:36   ` Simon Horman
2010-12-03 12:42     ` Simon Horman
2010-12-03 13:27     ` Ben Hutchings
2010-12-03 13:39       ` Simon Horman
2010-12-09  2:35     ` Simon Kirby
2010-12-09  2:51       ` Eric Dumazet [this message]
2010-12-22 23:39         ` Simon Kirby
2011-01-13  6:34           ` Simon Horman
2011-01-27  0:48             ` Simon Kirby
2011-01-27  1:36               ` Simon Horman
2011-01-27  7:42               ` Eric Dumazet
2011-01-27 14:42                 ` Simon Horman

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=1291863119.2795.29.camel@edumazet-laptop \
    --to=eric.dumazet@gmail.com \
    --cc=horms@verge.net.au \
    --cc=netdev@vger.kernel.org \
    --cc=sim@hostway.ca \
    /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