> >On 2015/11/18 1:25, Flavio Leitner wrote: >> On Wed, Nov 11, 2015 at 03:06:02PM +0000, Mark Kavanagh wrote: >>> Add support for Jumbo Frames to DPDK-enabled port types, >>> using single-segment-mbufs. >>> >>> Using this approach, the amount of memory allocated for each mbuf >>> to store frame data is increased to a value greater than 1518B >>> (typical Ethernet maximum frame length). The increased space >>> available in the mbuf means that an entire Jumbo Frame can be carried >>> in a single mbuf, as opposed to partitioning it across multiple mbuf >>> segments. >>> >>> The amount of space allocated to each mbuf to hold frame data is >>> defined by the user at compile time; if this frame length is not a >>> multiple of the DPDK NIC driver's minimum Rx buffer length, the frame >>> length is rounded up to the closest value that is. >>> >>> Signed-off-by: Mark Kavanagh <mark.b.kavan...@intel.com> >>> --- >>> INSTALL.DPDK.md | 67 ++++++++++++++++++++- >>> lib/netdev-dpdk.c | 176 >>> ++++++++++++++++++++++++++++++++++++++++++----------- >>> 2 files changed, 207 insertions(+), 36 deletions(-) >>> >>> diff --git a/INSTALL.DPDK.md b/INSTALL.DPDK.md >>> index 96b686c..9a30f88 100644 >>> --- a/INSTALL.DPDK.md >>> +++ b/INSTALL.DPDK.md >>> @@ -859,10 +859,70 @@ by adding the following string: >>> to <interface> sections of all network devices used by DPDK. Parameter 'N' >>> determines how many queues can be used by the guest. >>> >>> + >>> +Jumbo Frames >>> +------------ >>> + >>> +Support for Jumbo Frames may be enabled at compile-time for DPDK-type >>> ports. >> It seems this could be dynamic and proportional to the MTU being used >> by the port and not a compile-time option which depends on the NIC >> hardware specs. Perhaps I am missing something. > >It make sense. > >And this patch really solve a big issue that when I transmit 1400 packet >size, ovs-vsvitchd will return a "Bus error", although 1400 should not >be a Jumbo frame. >
Hi Michael, Thanks for your feedback; I'm glad to hear that the patch solved that issue for you - I'm curious as to why you experience the Bus error for 1400B packet though. >Mark, could it be an option when start vswitchd with dpdk, thus when >users try to using Jumbo Frame, it will not need to re-compile ovs, just >an advise :) > Agreed - I had intended to implement this functionality further down the line, depending on how this patch was received. I'll add a runtime flag in v2. >What's more, we could config it in run time, just like we dynamically >config the queue numbers, but this has a lot work to do, it could be a >further feature. Do you mean the 'other_config: n-dpdk-rxqs' field in the Open_vSwitch table? I'm not sure how amenable a solution like this would be to the maintainers, seeing as there is already an 'MTU' field present in the 'Interfaces' table. Ben/Pravin - any thoughts as to supporting a separate MTU field for DPDK interfaces? Thanks, Mark > >Thanks, >Michael >> Thanks, >> fbl >> >> _______________________________________________ >> dev mailing list >> dev@openvswitch.org >> http://openvswitch.org/mailman/listinfo/dev >> _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
