From: Ben Hutchings <ben@decadent.org.uk>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>,
therbert@google.com, netdev@vger.kernel.org
Subject: Re: [PATCH] net: Check skb->rxhash in gro_receive
Date: Wed, 15 Jan 2014 02:43:36 +0000 [thread overview]
Message-ID: <1389753816.3720.184.camel@deadeye.wl.decadent.org.uk> (raw)
In-Reply-To: <1389752827.31367.314.camel@edumazet-glaptop2.roam.corp.google.com>
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On Tue, 2014-01-14 at 18:27 -0800, Eric Dumazet wrote:
> On Wed, 2014-01-15 at 01:31 +0000, Ben Hutchings wrote:
>
> > When I investigated the scope of this for Debian, I tried sending a
> > 'packet of death' to a VM and actually triggered the lockup in the TX
> > path of the *host*, running Debian unstable with Linux 3.11. I didn't
> > track down exactly why that was but I think that libvirt's default
> > networking configuration includes multiqueue devices that use flow
> > dissector.
>
> OK, I take that majority of debian hosts are running some VM then,
> nice to know, time to update my hosts and usages I guess.
I said that common configurations use flow dissector - not the majority.
> Anyway, current flow dissector needs care if we really use it in
> unprotected areas.
>
> Hostile packets can force flow dissection of MTU bytes,
> bringing host to abysmal performance.
[...]
Yes. I think the number of times it can loop should be limited to some
small number.
Ben.
--
Ben Hutchings
Life is what happens to you while you're busy making other plans.
- John Lennon
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next prev parent reply other threads:[~2014-01-15 2:43 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-10 4:54 [PATCH] net: Check skb->rxhash in gro_receive Tom Herbert
2014-01-10 5:00 ` David Miller
2014-01-10 5:38 ` Eric Dumazet
2014-01-10 5:43 ` Eric Dumazet
2014-01-10 16:47 ` Tom Herbert
2014-01-10 16:27 ` Tom Herbert
2014-01-10 17:45 ` Eric Dumazet
2014-01-10 18:15 ` Tom Herbert
2014-01-10 18:54 ` Eric Dumazet
2014-01-10 19:42 ` Tom Herbert
2014-01-10 20:43 ` Eric Dumazet
2014-01-10 23:22 ` Tom Herbert
2014-01-13 19:59 ` David Miller
2014-01-13 20:13 ` Tom Herbert
2014-01-13 20:17 ` Eric Dumazet
2014-01-13 20:50 ` Ben Hutchings
2014-01-13 21:37 ` Eric Dumazet
2014-01-15 1:31 ` Ben Hutchings
2014-01-15 2:27 ` Eric Dumazet
2014-01-15 2:43 ` Ben Hutchings [this message]
2014-01-13 21:24 ` Tom Herbert
2014-01-13 21:36 ` Eric Dumazet
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