On Tue, Nov 14, 2017 at 10:52:03AM -0700, Blair Bethwaite wrote: > Thanks for the reply Daniel, > > However I think you slightly misunderstood the scenario... > > On 14 November 2017 at 10:32, Daniel P. Berrange <berrange@xxxxxxxxxx> wrote: > > IOW, if your application has a certain expectation of performance that can only > > be satisfied by having the KVM guest backed by huge pages, then you should > > really change to explicitly reserve huge pages for the guests, and not rely on > > THP which inherantly can't provide any guarantee in this area. > > We already do this. The problem is not hugepage backing of the guest, > it is THP allocation inside the guest (or indeed on a bare-metal > host). The issue in the HPC world is that we support so many different > applications (some of which are complete black-boxes) that explicit > hugepage allocation for application memory is generally not viable, so > we are reliant on THP to avoid TLB thrashing. Oh well THP usage inside the guest is then not really anything todo with virt, just a regular Linux questions, so not sure libvirt is the best place to ask. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :| _______________________________________________ libvirt-users mailing list libvirt-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvirt-users
