On Thu, 2012-10-04 at 16:48 +0200, Dick Snippe wrote: > $ sudo ethtool -k eth0 > Offload parameters for eth0: > rx-checksumming: on > tx-checksumming: on > scatter-gather: on > tcp-segmentation-offload: on > udp-fragmentation-offload: off > generic-segmentation-offload: on > generic-receive-offload: on > large-receive-offload: on > ntuple-filters: off > receive-hashing: on > > > If yes, the numer of ACK they are sending back should be limited to one > > ACK per GRO packet, instead of one ACK every 2 MSS. > > using sar -n DEV I saw +/- 150.000 rxpck/s on the sending webserver, > with +/- 9.000 rxkB/s, i.e. ~60 bytes/packet. I assume that these are > pure ACKs. But I don't know what sar counts exactly and how that relates > to GRO. > > > Also, I was considering adding GRO support of TCP pure ACK, at least for > > local traffic (not forwarding workloads) > > > > It would be nice if you could post a "perf top" output of the sender, > > because dropping to 1-2Gbit sounds really really bad... > > I'll have to look into that as we don't usually build perf with our > kernels and "make" in the tools/perf directory fails, probably because > our version of bison is too old. >
What is the average sent bytes per session ? I am asking because I dont really understand how you can have 150.000 pkt/sec. A 10Gb link would send about 820k MSS packets per sec. So even assuming one ACK per MSS, you should have about 820k packets/second. I wonder if the problem is not about SYN/SYNACK processing, because its currently serialized on a single listener lock. ------------------------------------------------------------------------------ Don't let slow site performance ruin your business. Deploy New Relic APM Deploy New Relic app performance management and know exactly what is happening inside your Ruby, Python, PHP, Java, and .NET app Try New Relic at no cost today and get our sweet Data Nerd shirt too! http://p.sf.net/sfu/newrelic-dev2dev _______________________________________________ E1000-devel mailing list E1000-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/e1000-devel To learn more about Intel® Ethernet, visit http://communities.intel.com/community/wired
