On Wed, Jan 11, 2017 at 10:34:00AM -0200, Marcelo Tosatti wrote: > On Wed, Jan 11, 2017 at 10:19:10AM -0200, Marcelo Tosatti wrote: > > > > Hi, > > > > Comments/questions related to: > > https://www.redhat.com/archives/libvir-list/2017-January/msg00354.html > > > > 1) root s2600wt:~/linux# virsh cachetune kvm02 --l3.count 2 > > > > How does allocation of code/data look like? > > > > 2) 'nodecachestats' command: > > > > 3. Add new virsh command 'nodecachestats': > > This API is to expose vary cache resouce left on each hardware (cpu > > socket). > > It will be formated as: > > <resource_type>.<resource_id>: left size KiB > > > > Does this take into account that only contiguous regions of cbm masks > > can be used for allocations? > > > > Also, it should return the amount of free cache on each cacheid. > > > > 3) The interface should support different sizes for different > > cache-ids. See the KVM-RT use case at > > https://www.redhat.com/archives/libvir-list/2017-January/msg00415.html > > "WHAT THE USER NEEDS TO SPECIFY FOR VIRTUALIZATION (KVM-RT)". > > And when the user specification lacks cacheid of a given socket in > the system, the code should use the default resctrlfs masks > (that is for the default group). > > > 4) Usefulness of exposing minimum unit size. > > > > Rather than specify unit sizes (which forces the user > > to convert every time the command is executed), why not specify > > in kbytes and round up? > > > > <resctrl name='L3' unit='KiB' cache_size='56320' > > cache_unit='2816'/> > > > > As noted in item 1 of > > https://www.redhat.com/archives/libvir-list/2017-January/msg00494.html, > > "1) Convertion of kbytes (user specification) --> number of CBM bits > > for host.", > > the format where the size is stored is kbytes, so its awkward > > to force users and OpenStack to perform the convertion themselves > > (and zero benefits... nothing changes if you know the unit size). > > 5) Please perform necessary filesystem locking as described > at Documentation/x86/intel_rdt_ui.txt in the kernel source. 6) libvirt API should expose the cacheid <-> pcpu mapping (when implementing cacheid support). -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
