I talked to Mingming, she suggested to use different IO scheduler. The default scheduler is cfg, after I switch to noop, the problem is gone. So there seems a bug in cfg scheduler. It's easily reproduced it when running the guest kernel, so far I haven't hit this problem on the host side. If I need to file a bug for some one to look at, please let me know. Thanks Shirley -- 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
