On Fri, Oct 11, 2019 at 05:00:32PM +0800, Lei Chen wrote: > Hi David, > Thanks in advance for reading my message. > > We are running UNH-IOL test on our product which is based on kernel > 4.4.178. The INTACT test cases failed on ipv6 verification. The same test > cases just got pass on 4.4.153. (Sorry, the INTACT suite does not look to > be open sourced. Hence I don't really know what the cases were indeed > doing.) > > Our verification engineer also mentioned: "The pattern of failures look > eerily similar to a regression we recently discovered in SLES 12. I.e., > Failures related to “Parameter Problems”, as well as “Fragmentation“." We > have tried to back out the defragment related patch: > > commit 5f2d68b6b5a439c3223d8fa6ba20736f91fc58d8 > Author: Florian Westphal > Date: Wed Oct 10 12:30:10 2018 -0700 > > ipv6: defrag: drop non-last frags smaller than min mtu > > commit 0ed4229b08c13c84a3c301a08defdc9e7f4467e6 upstream. > > don't bother with pathological cases, they only waste cycles. > IPv6 requires a minimum MTU of 1280 so we should never see fragments > smaller than this (except last frag). > > > But it doesn't help. Could you please shed a light on which patch between > 4.4.153 and 4.4.178 could have caused such a regression? Thanks again.
As you can run the test, why can't you run 'git bisect' to find the offending patch? thanks, greg k-h