On 10.10.2012, at 20:52, Christoffer Dall <c.dall@xxxxxxxxxxxxxxxxxxxxxx> wrote: > On Wed, Oct 10, 2012 at 2:50 PM, Alexander Graf <agraf@xxxxxxx> wrote: >> >> >> On 10.10.2012, at 20:39, Alexander Spyridakis >> <a.spyridakis@xxxxxxxxxxxxxxxxxxxxxx> wrote: >> >> For your information, with the latest developments related to VirtIO, I run >> netperf a couple of times to see the exact standing of network performance >> on the guests. >> >> The test was to run netperf -H "ip of LAN node", which tests TCP traffic for >> 10 seconds. >> >> x86 - x86: ~96 Mbps - reference between two different computers >> ARM Host - x86: ~80 Mbps >> ARM Guest - x86: ~ 2 Mbps - emulation >> ARM Guest - x86: ~74 Mbps - VirtIO >> >> From these we conclude that: >> >> As expected x86 to x86 communication can reach the limit of the 100 Mbps >> LAN. >> The ARM board seems to not be capable of the LAN. >> Network emulation in QEMU is more than just slow (expected). >> >> >> Why is this expected? This performance drop is quite terrifying. >> > > I think he means expected as in, we already know we have this > terrifying problem. I'm looking into this right now, and I believe > Marc is also on this. Ah, good :). Since you are on a dual-core machine with lots of traffic, you should get almost no vmexits for virtio queue processing. Since we know that this is a fast case, the big difference to emulated devices are the exits. So I'd search there :). Alex > > -Christoffer _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm
