> -----Original Message----- > From: adrian.ch...@gmail.com [mailto:adrian.ch...@gmail.com] On Behalf > Of Adrian Chadd > Sent: Saturday, March 7, 2015 4:27 PM > To: Wei Hu > Cc: Luigi Rizzo; freebsd-net@freebsd.org > Subject: Re: Network interrupt and NAPI in FreeBSD? > > Hi, > > Well, hm. What's generating the interrupts? How many interrupts/second > are you talking about here? > > People have asked about a NAPI style solution for FreeBSD for a while, but > for most folk that are using one physical interface that does interrupt > moderation/rate-limiting, it turns out to not be all that big a benefit. For > boxes that haves multiple interfaces, or for VMs whose software interrupt > path doesn't implement any kind of thresholds for interrupt moderation, it > still can be a benefit. > > So maybe try looking at making your driver support POLLING and see what > happens. > > Maybe virtualisation will be the straw that breaks the NAPI back for > FreeBSD. ;) >
I haven't got chance to measure the interrupt/second rate. What I have seen is when running the same iperf test, the vCPU handle the network queue is over 80% busy running in interrupt context on FreeBSD, comparing to around 15% busy in interrupt context on Linux. The throughput is around 2.0 Gbps vs 3.0 Gbps. I am using a slightly new netvsc driver with TSO support. It hasn't not been officially out yet. Wei _______________________________________________ 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"
