Hello. I noticed that window7, unlike windowsXP as I played with previously, poses quite high load on host when idle. On my machine, host cpu usage is about 25% when one single-cpu win7 guest is running with "-usbdevice tablet" option. Here's a typical kvm_stats when such a guest is idling: efer_reload 0 0 exits 991832 695 fpu_reload 3786 0 halt_exits 7759 67 halt_wakeup 7717 67 host_state_reload 613116 495 hypercalls 0 0 insn_emulation 873244 488 insn_emulation_fail 0 0 invlpg 0 0 io_exits 582925 409 irq_exits 30188 8 irq_injections 41093 0 irq_window 0 0 largepages 288 0 mmio_exits 16718 0 mmu_cache_miss 217 0 mmu_flooded 0 0 mmu_pde_zapped 0 0 mmu_pte_updated 0 0 mmu_pte_write 0 0 mmu_recycled 0 0 mmu_shadow_zapped 269 0 mmu_unsync 0 0 nmi_injections 0 0 nmi_window 0 0 pf_fixed 20630 0 pf_guest 0 0 remote_tlb_flush 176 0 request_irq 0 0 Here -- http://www.corpit.ru/mjt/kvm-trace-w7-idle -- are some results from /sys/kernel/debug/tracing/events/kvm/enable (taken from /sys/kernel/debug/tracing/trace_pipe). The file's >5Mb in size. When I run the same guest without -usbdevice tablet, it idles at about 3..4% host CPU time -- still a bit high but acceptable. Here's a typical kvm_stats output withOUT usb tablet: efer_reload 0 0 exits 1204081 686 fpu_reload 4235 2 halt_exits 12116 67 halt_wakeup 12047 67 host_state_reload 797865 493 hypercalls 0 0 insn_emulation 1074589 473 insn_emulation_fail 0 0 invlpg 0 0 io_exits 761834 408 irq_exits 22240 12 irq_injections 33099 0 irq_window 0 0 largepages 304 0 mmio_exits 16718 0 mmu_cache_miss 220 0 mmu_flooded 0 0 mmu_pde_zapped 0 0 mmu_pte_updated 0 0 mmu_pte_write 0 0 mmu_recycled 0 0 mmu_shadow_zapped 271 0 mmu_unsync 0 0 nmi_injections 0 0 nmi_window 0 0 pf_fixed 18790 0 pf_guest 0 0 remote_tlb_flush 109 0 request_irq 0 0 And here's the two tables combined (last column from the above two tables, without and with usbmouse): statistics without with efer_reload 0 0 exits 686 695 fpu_reload 2 0 halt_exits 67 67 halt_wakeup 67 67 host_state_reload 493 495 hypercalls 0 0 insn_emulation 473 488 insn_emulation_fail 0 0 invlpg 0 0 io_exits 408 409 irq_exits 12 8 irq_injections 0 0 irq_window 0 0 largepages 0 0 mmio_exits 0 0 mmu_cache_miss 0 0 mmu_flooded 0 0 mmu_pde_zapped 0 0 mmu_pte_updated 0 0 mmu_pte_write 0 0 mmu_recycled 0 0 mmu_shadow_zapped 0 0 mmu_unsync 0 0 nmi_injections 0 0 nmi_window 0 0 pf_fixed 0 0 pf_guest 0 0 remote_tlb_flush 0 0 request_irq 0 0 So basically they're quite similar to each other, give or take some random fluctuations. kvm version is 0.12.5, kvm command line: kvm -nodefaults -m 1G \ -drive file=w7.raw,cache=none,boot=on,if=virtio \ -monitor stdio \ -vga std \ -device virtio-net-pci,netdev=net \ -netdev type=tap,ifname=tap-kvm,id=net -no-hpet -mem-path /dev/hugepages/ (and also -usbdevice tablet). I especially disabled almost everything (incl. hpet) and used "light" virtio drivers in order to try to reduce load as much as possible. The host CPU is AthlonII X2 260 (Regor). Anyone know how to make w7 less idle-hungry for usb? Thanks! /mjt -- 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
