On 05.03.2014 04:11, Adrian Chadd wrote: > Hi, > > On 4 March 2014 04:14, Eugene Grosbein <egrosb...@rdtc.ru> wrote: >> On 04.03.2014 08:17, Adrian Chadd wrote: >> >>> I'll try this out in the next week or two once I've sorted out my >>> employment situation and I can reserve some time on the netperf >>> cluster. >> >> There is a patch written by melif...@freebsd.org to introduce >> IP flow id generation and modified by me to add sysctl >> net.inet.ip.skip_flowid_gen to disable id generation in run time >> and return pre-patched behavior: >> >> http://www.grosbein.net/freebsd/patches/netisr_ip_flowid.diff >> >> I've tested it in production for mpd5-based high loaded BRAS, it works just >> fine. >> It uses IP src/dst addresses and TCP/UDP/SCTP ports to feed >> jenkins_hashword() >> and to fill m->m_pkthdr.flowid. > > Hm, is this actually going to work for all paths through ip_output? > Only a couple of paths go via netisr_queue(); the rest go via > ifp->if_output. Is that going to loop back through the netisr outbound > path? > > For some workloads we'll want to fill this in with the topelitz hash > that matches the RX flow from the NIC, just to keep locking/processing > of that flow on the same core. > > And to answer Slawa's email - yes, mainly because it's a subset of > what's needed for doing this for TCP. In the TCP case, the hashing is > already done for us on inbound connections; but there's still the > whole missing bits from Robert's work to tie in the pcbgroup handling > and the whole multi-queue / multi-listener thing that Linux and now > DragonflyBSD does. > > But there's a handful of silly things that need to be first > investigated and checked - like, ensuring that it works fine with > fragmented IP frames and re-encapsulated things - just to ensure that > they don't break the RSS model. > > Why'd you have to do an m_pullup() here in this path, which ideally > should just be a lookup only path? Are you actually seeing the IP/TCP > headers spread across multiple mbufs? They're not being snuck into > mbuf headroom at all?
I cannot answer these questions, CC'ing author of the patch, Alexander Chernikov. Eugene Grosbein _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
