> On Dec. 10, 2015, 12:27 a.m., Jie Yu wrote: > > This is more like a question: do we need to turn off tx side as well?
This is not needed, because 1) the physical interface can finally checksum it after it moves out of the container to the gateway interface; 2) if the physcial interface is not able to do it, the kernel can do it right before delivering it. - Cong ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/41158/#review109644 ----------------------------------------------------------- On Dec. 9, 2015, 11:15 p.m., Cong Wang wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviews.apache.org/r/41158/ > ----------------------------------------------------------- > > (Updated Dec. 9, 2015, 11:15 p.m.) > > > Review request for mesos, Ian Downes and Jie Yu. > > > Bugs: MESOS-4105 > https://issues.apache.org/jira/browse/MESOS-4105 > > > Repository: mesos > > > Description > ------- > > We noticed that in some cases we delivered some corrupt packets to > applications running in our containers. This is clearly wrong. > > Here is what happens: > > 1) We receive a corrupt packet externally > 2) The hardware driver is able to checksum it and notices it has a bad > checksum > 3) The driver delivers this packet anyway to wait for TCP layer to checksum > it again and then drop it > 4) This packet is moved to a veth interface because it is for a container > 5) Both sides of the veth pair have RX checksum offloading by default > 6) The veth_xmit() marks the packet's checksum as UNNECESSARY since its peer > device has rx checksum offloading > 7) Packet is moved into the container TCP/IP stack > 8) TCP layer is not going to checksum it since it is not necessary > 9) The packet gets delivered to application layer > > > Diffs > ----- > > src/slave/containerizer/mesos/isolators/network/port_mapping.cpp > 89bb36f936417de8169a2442729fbd7c9d60acb7 > > Diff: https://reviews.apache.org/r/41158/diff/ > > > Testing > ------- > > 1) Turn rx checksum off manually and the bug is gone > 2) Test this patch and verify rx checksum is turned off as expected. > 3) I don't see any noticable performance issue after turning this off > > > Thanks, > > Cong Wang > >
