On Thu, 2020-06-11 at 14:00 -0300, Daniel Henrique Barboza wrote: > On Linux, changing the nodeset on 'numatune' does not imply that > the guest memory will be migrated on the spot to the new nodeset. > The memory migration is tied on guest usage of the memory pages, > and an idle guest will take longer to have its memory migrated > to the new nodeset. > > This is a behavior explained in detail in the Linux kernel documentation > in Documentation/admin-guide/cgroup-v1/cpusets.rst. The user doesn't > need this level of detail though - just needs his/her expectations > under check. Running 'numastat' and hoping for instant memory > migration from the previous nodeset to the new one is not > viable. > > There's also parts of the memory that are locked by QEMU in the > same place, e.g. when VFIO devices are present. Let's also > mention it as another factor that impacts the results the > user might expect from NUMA memory migration with numatune. > > Signed-off-by: Daniel Henrique Barboza <danielhb413@xxxxxxxxx> > --- > docs/manpages/virsh.rst | 7 +++++++ > 1 file changed, 7 insertions(+) I've tweaked the formatting for the manpage and commit message ever so slightly, added a reference to https://bugzilla.redhat.com/show_bug.cgi?id=1640869 and pushed. Thanks! -- Andrea Bolognani / Red Hat / Virtualization
