On Tue, Aug 10, 2010 at 06:23:24PM -0700, Shirley Ma wrote: > Hello Xiaohui, > > On Fri, 2010-08-06 at 17:23 +0800, xiaohui.xin@xxxxxxxxx wrote: > > Our goal is to improve the bandwidth and reduce the CPU usage. > > Exact performance data will be provided later. > > Have you had any performance data to share here? I tested my > experimental macvtap zero copy for TX only. The performance I have seen > as below without any tuning, (default setting): > > Before: netperf 16K message size results with 60 secs run is 7.5Gb/s > over ixgbe 10GbE card. perf top shows: > > 2103.00 12.9% copy_user_generic_string > 1541.00 9.4% handle_tx > 1490.00 9.1% _raw_spin_unlock_irqrestore > 1361.00 8.3% _raw_spin_lock_irqsave > 1288.00 7.9% _raw_spin_lock > 924.00 5.7% vhost_worker > > After: netperf results with 60 secs run is 8.1Gb/s, perf output: > > 1093.00 9.9% _raw_spin_unlock_irqrestore > 1048.00 9.5% handle_tx > 934.00 8.5% _raw_spin_lock_irqsave > 864.00 7.9% _raw_spin_lock > 644.00 5.9% vhost_worker > 387.00 3.5% use_mm > > I am still working on collecting more data (latency, cpu > utilization...). I will let you know once I get all data for macvtap TX > zero copy. Also I found some vhost performance regression on the new > kernel with tuning. I used to get 9.4Gb/s, now I couldn't get it. > > Shirley Could you please try disabling mergeable buffers, and see if this gets you back where you were? -global virtio-net-pci.mrg_rxbuf=off -- MST -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
