I used lmbench, and even simple test shows the difference here. Simple read/writes (but not open/close?) seem to take much longer. Perhaps this over simplifies things, but it's repeatable. Any thoughts? Other tests that might be interesting? ubuntu-12.04 - first boot ========================================== Simple syscall: 0.0527 microseconds Simple read: 0.1143 microseconds Simple write: 0.0953 microseconds Simple open/close: 1.0432 microseconds ubuntu-12.04 - post live migration ========================================== Simple syscall: 0.0621 microseconds Simple read: 0.2485 microseconds Simple write: 0.2252 microseconds Simple open/close: 1.4626 microseconds ubuntu-10.04 - first boot ========================================== Simple syscall: 0.0524 microseconds Simple read: 0.1135 microseconds Simple write: 0.0972 microseconds Simple open/close: 1.1261 microseconds ubuntu-10.04 - post live migration ========================================== Simple syscall: 0.0526 microseconds Simple read: 0.1075 microseconds Simple write: 0.0951 microseconds Simple open/close: 1.0413 microseconds Regards, mark > On Wed, Dec 19, 2012 at 12:43:37AM +0000, Mark Petersen wrote: > > Hello KVM, > > > > I'm seeing something similar to this (http://thread.gmane.org/gmane.comp.emulators.kvm.devel/100592) as well when doing live migrations on Ubuntu 12.04 (Host and Guest) with a backported libvirt 1.0 and qemu-kvm 1.2 (improved performance for live migrations on guests with large memory guests is great!) The default libvirt 0.9.8 and qemu-kvm 1.0 have the same issue. > > > > Kernel is 3.2.0-34-generic and eglicb 2.15 on both host/guest. I'm seeing similar issues with both virtio and ide bus. Hugetblfs is not used, but transparent hugepages are. Host machines are dual core Xeon E5-2660 processors. I tried disabling EPT but that doesn't seem to make a difference so I don't think it's a requirement to reproduce. > > > > If I use Ubuntu 10.04 guest with eglibc 2.11 and any of these kernels I don't seem to have the issue: > > > > linux-image-2.6.32-32-server - 2.6.32-32.62 > > linux-image-2.6.32-38-server - 2.6.32-38.83 > > linux-image-2.6.32-43-server - 2.6.32-43.97 > > linux-image-2.6.35-32-server - 2.6.35-32.68~lucid1 > > linux-image-2.6.38-16-server - 2.6.38-16.67~lucid1 > > linux-image-3.0.0-26-server - 3.0.0-26.43~lucid1 > > linux-image-3.2-5 - mainline 3.2.5 kernel ______________________________________________ See http://www.peak6.com/email_disclaimer/ for terms and conditions related to this email -- 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
