Is the checksum offloading patch for the igb(4) driver available online? (I could not find it) I would really like to take a look at it, espacially the context descriptor part of it.
Best regards, Dominik On 16.06.2016 02:04, Jim Thompson wrote: > > Luiz Otavio O Souza (loos@) developed these for igb(4) and, by extension, > em(4) for use in netmap-fwd. > > He’s just gone back to Brazil with 82599 ixgb(4) hardware. I’m sure he’ll > develop similar patches for ixgb(4) in the near future. > > Chelsio is also “on the list”, but I figured I’d speak to np@ about it first. > ;-) > We might do ixl(4) as well. > > Before Luiz retired to Brazil, we discussed upstreaming these to FreeBSD. > We’re committed to make it happen, but I doubt they make 11. > > Jim > >> On Jun 15, 2016, at 6:50 PM, Navdeep Parhar <n...@freebsd.org> wrote: >> >> On 06/15/2016 16:15, Andrey Yakovlev wrote: >>> ive heard on bsdcan this year that some patches exist to add hwcsum >>> offloading to netmap, hope to see it chelsio at least >> >> cxgbe/cxl is a bit sneaky and will let you override netmap (on tx only). >> The ncxl interfaces declare themselves capable of checksumming but all >> such capabilities are disabled by default. Just enable txcsum on the >> interface and the hardware will do checksum insertion on tx. No way to >> solve the rx part entirely within the driver -- netmap has to be willing >> to accept checksum related flags from the driver. >> >> Regards, >> Navdeep >> >>> >>> -- >>> ./andy >>> >>> >>> 14.06.2016, 12:15, "Dominik Schoeffmann" <schoe...@in.tum.de>: >>>> Dear Netmap Developers, >>>> >>>> during the course of my bachelor's thesis, I modified a packet generator >>>> called MoonGen [1] in order to utilize netmap. >>>> One key component was to flexibly offload checksums for different kinds >>>> of packets (IPv4, UDP, TCP). >>>> The ixgbe netmap patch was modified [2] in order to construct context >>>> descriptors and suitable data descriptors. This is implemented in less >>>> than 250 LoC (including pseudo-header calculations). >>>> The man page states, that checksum offloading is available via ethtool, >>>> although a solution inside the netmap API might be a cleaner way for >>>> applications to actually use these features. >>>> Attached is a graph showing the performance implication of using >>>> offloading in the current implementation. >>>> As can be seen, offloading has only a minor impact. >>>> When regarding this data (and comparing it to other frameworks), please >>>> keep in mind, that internally a lot of per-packet effort is needed due >>>> to the software architecture of the packet generator. >>>> >>>> The question being: >>>> Would it not make sense to include checksum offloading inside of netmap >>>> in order to accomodate applications operating on layer 3 and above? >>>> As these programs need to calculate the checksums in software, it would >>>> be just as fast to move these calculations to the kernel for NICs >>>> without checksum offloading support (and the kernel would act as a >>>> library). >>>> The problem which currently is imposed by the fact, that netmap exports >>>> the complete ring, is that context descriptors disrupt the data >>>> descriptors, which is unpleasant for the application. >>>> But you may find the data interesting nevertheless. >>>> >>>> Best Regards, >>>> Dominik Schoeffmann >>>> >>>> [1] https://github.com/dschoeffm/MoonGen/tree/netmap >>>> [2] https://github.com/dschoeffm/netmap/tree/mg-chksum-offloading >>> _______________________________________________ >>> freebsd-net@freebsd.org mailing list >>> https://lists.freebsd.org/mailman/listinfo/freebsd-net >>> To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org" >>> >> >> _______________________________________________ >> freebsd-net@freebsd.org mailing list >> https://lists.freebsd.org/mailman/listinfo/freebsd-net >> To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org" >
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