On Mon, Nov 21, 2022 at 07:28:36PM -0700, Song Liu wrote: > On Mon, Nov 21, 2022 at 1:12 PM Luis Chamberlain <mcgrof@xxxxxxxxxx> wrote: > > > > Also, you mention your perf stats are run on a VM, I am curious what > > things you need to get TLB to be properly measured on the VM and if > > this is really reliable data Vs bare metal. I haven't yet been sucessful > > on getting perf stat for TBL to work on a VM and based on what I've read > > have been catious about the results. > > To make these perf counters work on VM, we need a newer host kernel > (my system is running 5.6 based kernel, but I am not sure what is the > minimum required version). Then we need to run qemu with option > "-cpu host" (both host and guest are x86_64). > > > > > So curious if you'd see something different on bare metal. > > Once the above all worked out, VM runs the same as bare metal from > perf counter's point of view. TLBs behave differently because of EPT. -- Sincerely yours, Mike.
