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Description of problem: When you start the virtual machine, and further work on the host system - slows down in graphics applications. In this case the system load is minimal. This occurs in approximately equal intervals (slowing down for 5 minutes and 10 minutes of normal operation). Version-Release number of selected component (if applicable): 1. 2.6.32-131.17.1.el6.x86_64 2. qemu-kvm-0.12.1.2-2.160.el6_1.8.x86_64 3. Virtual machines (linux,windows) 4. Kernel config: # CONFIG_TREE_PREEMPT_RCU is not set CONFIG_PREEMPT_NOTIFIERS=y # CONFIG_PREEMPT_NONE is not set CONFIG_PREEMPT_VOLUNTARY=y # CONFIG_PREEMPT is not set Hardware: 1. Core i7 920 2. 12 Gb DDR3 3. two raid10 sata 3 Gb/s What has been tested: 1. CPU (create archive) 2. RAM (check for errors) 3. soft raid (180 Mb/s average speed) 4. iostat 5. perf top 6. Disabling the periphery 7. Put kernel parameters acpi=off 8. Disable and remove pulseaudio 9. Full disable selinux 10. Set in cgroup for user: cpu.shares=10000; cpu.rt_runtime_us=900000; cpu.rt_period_us=1000000; blkio.weight=1000; How reproducible: Run virtual machine and work with graphics applications. Additional info: Search in google: http://lkml.indiana.edu/hypermail/linux/kernel/0707.3/0698.html Current kvm disables preemption while the new virtualization registers are in use. This of course is not very good for latency sensitive workloads (one use of virtualization is to offload user interface and other latency insensitive stuff to a container, so that it is easier to analyze the remaining workload). This patch re-enables preemption for kvm; preemption is now only disabled when switching the registers in and out, and during the switch to guest mode and back.
Since RHEL 6.3 External Beta has begun, and this bug remains unresolved, it has been rejected as it is not proposed as exception or blocker. Red Hat invites you to ask your support representative to propose this request, if appropriate and relevant, in the next release of Red Hat Enterprise Linux.
The link you posted is outdated, it has been merged long ago. What exactly are you experiencing? Are you sure it isn't just the impact of the extra cpu load?
Using 6.3 on same hardware - all is good. CPU/GPU load is high, but no freeze.