From: Willy Tarreau <w@1wt.eu>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Hillf Danton <dhillf@gmail.com>,
Johannes Truschnigg <johannes@truschnigg.info>,
linux-kernel@vger.kernel.org,
Linux-Netdev <netdev@vger.kernel.org>
Subject: Re: PROBLEM: Silent data corruption when using sendfile()
Date: Sat, 14 Jul 2012 10:31:36 +0200 [thread overview]
Message-ID: <20120714083136.GO16256@1wt.eu> (raw)
In-Reply-To: <1342254042.3265.9017.camel@edumazet-glaptop>
On Sat, Jul 14, 2012 at 10:20:41AM +0200, Eric Dumazet wrote:
> > On Tue, Jul 3, 2012 at 8:02 AM, Willy Tarreau <w@1wt.eu> wrote:
> > >
> > > In fact it has been true zero copy in 2.6.25 until we faced a large
> > > amount of data corruption and the zero copy was disabled in 2.6.25.X.
> > > Since then it remained that way until you brought your patches to
> > > re-instantiate it.
>
> Might be, or not (could be a NIC bug)
I may be wrong but what I recall from this bug was an issue when
forwarding TCP between two NICs, related to linear vs non-linear
data (I have memories of something around data not yet ACKed being
replaced before being retransmitted but I may be wrong). Anyway,
the way it was fixed consisted in simply disabling the zero-copy
code path. So this should be something different from what Johannes
reports. Maybe a regression since then though.
> Please Johannes could you try latest kernel tree ?
It would be useful, especially given the amount of changes you performed
in this area in latest version, it could be very possible that this new
bug got fixed as a side effect !
Regards,
Willy
next prev parent reply other threads:[~2012-07-14 8:31 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-13 17:18 PROBLEM: Silent data corruption when using sendfile() Johannes Truschnigg
2012-07-14 8:04 ` Hillf Danton
2012-07-14 8:20 ` Eric Dumazet
2012-07-14 8:31 ` Willy Tarreau [this message]
2012-07-14 10:13 ` Johannes Truschnigg
2012-07-14 10:33 ` Eric Dumazet
2012-07-14 10:44 ` Willy Tarreau
2012-07-14 11:06 ` Eric Dumazet
2012-07-14 13:15 ` Willy Tarreau
2012-07-14 17:09 ` Johannes Truschnigg
2012-07-14 11:44 ` Thorsten Kranzkowski
2012-07-14 14:08 ` Hillf Danton
2012-07-14 14:19 ` Eric Dumazet
2012-07-14 14:56 ` Willy Tarreau
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