Il 26/08/2013 21:15, Brian Rak ha scritto: > > Samples: 62M of event 'cycles', Event count (approx.): 642019289177 > 64.69% [kernel] [k] _raw_spin_lock > 2.59% qemu-system-x86_64 [.] 0x00000000001e688d > 1.90% [kernel] [k] native_write_msr_safe > 0.84% [kvm] [k] vcpu_enter_guest > 0.80% [kernel] [k] __schedule > 0.77% [kvm_intel] [k] vmx_vcpu_run > 0.68% [kernel] [k] effective_load > 0.65% [kernel] [k] update_cfs_shares > 0.62% [kernel] [k] _raw_spin_lock_irq > 0.61% [kernel] [k] native_read_msr_safe > 0.56% [kernel] [k] enqueue_entity Can you capture the call graphs, too (perf record -g)? > I've captured 20,000 lines of kvm trace output. This can be found > https://gist.github.com/devicenull/fa8f49d4366060029ee4/raw/fb89720d34b43920be22e3e9a1d88962bf305da8/trace The guest is doing quite a lot of exits per second, mostly to (a) access the ACPI timer (b) service NMIs. In fact, every NMI is reading the timer too and causing an exit to QEMU. So it is also possible that you have to debug this inside the guest, to see if these exits are expected or not. Paolo -- 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