Messages in this thread |  | | | Date | Tue, 6 Jan 2009 16:57:15 +0100 | | From | Willy Tarreau <> | | Subject | Re: Data corruption issue with splice() on 2.6.27.10 |
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On Tue, Jan 06, 2009 at 10:01:13AM +0000, Jarek Poplawski wrote: > On Tue, Jan 06, 2009 at 10:41:38AM +0100, Willy Tarreau wrote: > ... > > > Great story! Alas I don't understand this fully either, but it seems > > > Changli Gao was concerned with sendpage sending this "as pages", so > > > when NETIF_F_SG flag is available. Did you try this without SG btw? > > No I did not. I can try, it's not too hard. It would in part defeat the > > purpose of the mechanism (especially at 10 Gbps) but at least it will > > help narrow the problem down. > > Yes, I meant it only as a proof of concept. BTW, delaying TCP acks a > bit for these sendpages should then make it more reproducible, I guess.
OK here is an update. It does not change anything to turn off any acceleration feature on the interface (tg3) :
root@wtap:~# ethtool -k eth0 Offload parameters for eth0: rx-checksumming: off tx-checksumming: off scatter-gather: off tcp segmentation offload: off
It still forwards corrupted data like mad. I noticed that the corruption rate is 10-100 times higher when forwarding from eth0 to eth0 than from eth0 to lo.
Maybe this can help find the culprit ?
Willy
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