can you tell me something about this problem. thanks. 2010/11/23 Avi Kivity <avi@xxxxxxxxxx>: > On 11/23/2010 04:53 AM, lidong chen wrote: >> >> Test method: >> Send the same traffic load between virtio_pci MSI-X disable and >> enable,and compare the cpu rate of host os. >> I used the same version of virtio driver, only modify the msi-x option. >> the host os version is 2.6.32. >> the virtio dirver is from rhel6. >> the guest version os is 2.6.16. >> >> Test result: >> with msi-x disable, the cpu rate of host os is 110%. >> with msi-x enable, the cpu rate of host os is 140%. >> > ... > >> Conclusion: >> msi-x enable waste more cpu resource is caused by MSIX mask bit. In >> older kernels program this bit twice >> on every interrupt. and caused ept violation. >> >> So I think we should add a param to control this.with older kernels, >> we should disable MSIX. >> And I think this should deal by qemu. > > There is now work in progress (by Sheng Yang) to speed up mask bit > emulation, which should improve things. Also, newer kernels don't hit the > mask bit so hard. You might try to backport the mask bit patches to your > 2.6.16 guest. > > -- > I have a truly marvellous patch that fixes the bug which this > signature is too narrow to contain. > > -- 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
