Hi, I've experienced some queue timeout problems mentioned in the subject with igb and bnx2 cards. I haven't seen them on other cards so far. I'm using XenServer with 3.10 Dom0 kernel (however igb were already updated to latest version), and there are Windows guests sending data through these cards. I noticed these problems in XenRT test runs, and I know that they usually mean some lost interrupt problem or other hardware error, but in my case they started to appear more often, and they are likely connected to my netback grant mapping patches. These patches causing skb's with huge (~64kb) linear buffers to appear more often. The reason for that is an old problem in the ring protocol: originally the maximum amount of slots were linked to MAX_SKB_FRAGS, as every slot ended up as a frag of the skb. When this value were changed, netback had to cope with the situation by coalescing the packets into fewer frags. My patch series take a different approach: the leftover slots (pages) were assigned to a new skb's frags, and that skb were stashed to the frag_list of the first one. Then, before sending it off to the stack it calls skb = skb_copy_expand(skb, 0, 0, GFP_ATOMIC, __GFP_NOWARN), which basically creates a new skb and copied all the data into it. As far as I understood, it put everything into the linear buffer, which can amount to 64KB at most. The original skb are freed then, and this new one were sent to the stack. I suspect that this is the problem as it only happens when guests send too much slots. Does anyone familiar with these drivers have seen such issue before? (when these kind of skb's get stucked in the queue)
Regards, Zoltan Kiss ------------------------------------------------------------------------------ WatchGuard Dimension instantly turns raw network data into actionable security intelligence. It gives you real-time visual feedback on key security issues and trends. Skip the complicated setup - simply import a virtual appliance and go from zero to informed in seconds. http://pubads.g.doubleclick.net/gampad/clk?id=123612991&iu=/4140/ostg.clktrk _______________________________________________ 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
