The buffer containing the data is not in a single buffer coming down to the driver. I'm not sure what kind of stack you supplying the data but maybe you should try to have all the data in a single larger buffer that is then used in the skb.
Cheers, John > -----Original Message----- > From: Yan, Liming (NSN - CN/Hangzhou) [mailto:[email protected]] > Sent: Friday, March 08, 2013 1:20 AM > To: [email protected] > Subject: [E1000-devel] my skb not linear when whole packet len only 513 > bytes > > Hi, > I'm sending non-IP packets with dev_queue_xmit. It's not linear as > expected in receiving side when whole packet len only 513 bytes(include > mac header). 513 bytes is a boundary because if I use 512, it's ok. > Anybody know what may cause this problem? Thanks. My MTU is 1500. > > In sending side, I print the skb, seems it's normal: > >> Mar 9 22:41:03.972683 info CLA-0 kernel: [251326.875463]: before > dev_queue_xmit: skb->data_len=0, skb->len=513. > > In receiving side, I register my softirq handler with own ether-type. > The skb I got from kernel is: > >> Mar 9 22:41:03.973199 info CLA-1 kernel: [11139.235550]: skb- > >data_len=1,skb->len=499. > So skb_is_nonlinear return true when skb->data_len>0. > > Kernel version: 2.6.34.13 > > 82599 firmware and driver version: > # ethtool -i bi0 > driver: igb > version: 2.4.12 > firmware-version: 2.1-3 > bus-info: 0000:02:00.0 > > # ifconfig bi0 > bi0 Link encap:Ethernet HWaddr 00:A0:A5:64:DB:FA > UP BROADCAST RUNNING SLAVE MULTICAST MTU:1500 Metric:1 > RX packets:46846508 errors:0 dropped:0 overruns:0 frame:0 > TX packets:47748723 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:1000 > RX bytes:5803096993 (5.4 GiB) TX bytes:55743743072 (51.9 > GiB) > > --------------------------------------------------------------------- > Best Regards. > Liming ------------------------------------------------------------------------------ Symantec Endpoint Protection 12 positioned as A LEADER in The Forrester Wave(TM): Endpoint Security, Q1 2013 and "remains a good choice" in the endpoint security space. For insight on selecting the right partner to tackle endpoint security challenges, access the full report. http://p.sf.net/sfu/symantec-dev2dev _______________________________________________ E1000-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/e1000-devel To learn more about Intel® Ethernet, visit http://communities.intel.com/community/wired
