10.09.2010 16:19, Avi Kivity wrote: > On 09/03/2010 03:21 PM, Michael Tokarev wrote: >> 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: [] > That's pretty good for an idle guest. Hm. Well. Sometimes it goes "a bit" further than that: efer_reload 0 0 exits 6307547 12445 fpu_reload 39995 49 halt_exits 74950 50 halt_wakeup 72075 49 host_state_reload 2150687 5585 hypercalls 0 0 insn_emulation 3218768 6337 insn_emulation_fail 0 0 invlpg 0 0 io_exits 962906 5012 irq_exits 190637 436 irq_injections 31017 2 irq_window 0 0 largepages 0 0 mmio_exits 1076036 496 mmu_cache_miss 31812 9 mmu_flooded 0 0 mmu_pde_zapped 0 0 mmu_pte_updated 0 0 mmu_pte_write 9818 9 mmu_recycled 0 0 mmu_shadow_zapped 43946 0 mmu_unsync 0 0 nmi_injections 0 0 nmi_window 0 0 pf_fixed 2553881 5512 pf_guest 0 0 remote_tlb_flush 4502 0 request_irq 0 0 It happens every few seconds, but it does not look like this is the cause of high CPU load, most likely it's some periodic tasks that really triggers every few secs, not more often, so almost does not add to the average and min loads. > What does the guest think it is doing? The Windows performance monitor? Nothing. It shows perfmon.exe using 3% CPU, and that's about it. I'm attaching a .png screenshot of the KVM window with w7 perfmon running. Unfortunately I don't have English version handy, it's all in Russian, and I weren't able to change system language to English. But it is still readable. During this shot, host CPU was about 30..35% in use - higher than usual 25%, but I guess it's due to perfmon. Also, I haven't found a way to see, for example, individual interrupt activity in windows (like /proc/interrupts in linux). Thanks! /mjt
Attachment:
w7-perfmon-ru-idle.png
Description: PNG image
