On 08/27/2012 12:51 PM, Dong Hao wrote: > From: Xiao Guangrong <xiaoguangr...@linux.vnet.ibm.com> > > 'perf kvm stat record/report' will use kvm_exit and kvm_mmio(read...) to > calculate mmio read emulated time for the old kernel, in order to trace > mmio read event more exactly, we add kvm_mmio_begin to trace the time when > mmio read begins, also, add kvm_io_done to trace the time when mmio/pio is > completed >
Why is this so critical? If a lot of time is spent in in-kernel mmio, then 'perf top' will report it. Otherwise the time between kvm_exit and kvm_entry describes the time spent in the host. Not all of it is mmio handling, but it is quite close. -- error compiling committee.c: too many arguments to function -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
