hello, sorry for the delay, Le Thu, Feb 23, 2012 at 10:38:07AM +0200, Gleb Natapov ecrivait : > > Ah, I guess the reason is that it records events only of IO thread. You > need to trace all vcpu threads too. Not sure trace-cmd allows more then > one -P option though. I manage to have the physical server with only one VM with the slowly function and take trace during the slowly function. I upload trace in http://www.roullier.net/Report/ with : o report.txt.3.1.gz : with kernel 3.1 o report.txt.3.2.gz : with kernel 3.2 o report.txt.vhost-net-3.1.gz : with kernel 3.1 and vhost-net o report.txt.vhost-net.3.2.gz : with kernel 3.2 and vhost-net With 3.2 + vhost-net we have 10.5s (to remember 8s with vmware esxi 4). David. -- 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