Am Freitag, 12. Dezember 2014, 14:31:49 schrieben Sie:

On Fri, 2014-12-12 at 22:30 +0100, Thomas Jarosch wrote:

quoted

if it's any help: Disabling TX checksumming prevents the hang
even on an unpatched 3.14.x kernel. You could check with your debug
statements in place the path of the packets with and without TX
checksumming.

I can't disable it as the driver will not allow it:
# ethtool -K eth0 tx off
Cannot change tx-checksumming
Could not change any device features

Disabling TX checksum automatically disables GSO.

Disabling TSO/GSO is the real 'cure' for the time being, you can keep TX
checksums.

This does not help here. With GSO disabled (for network device serving the 
ipsec traffic, here e.g. eth0) the hang still occurs. tcp_set_skb_tso_segs() 
gets called and the else-branch for skb->len <= mss_now is taken.

I tested this serveral times.

Regards,
-- 
Wolfgang Walter
Studentenwerk München
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