On Wed, 2020-06-10 at 16:14 -0700, Gordon Messmer wrote: > On 6/10/20 9:36 AM, Patrick O'Callaghan wrote: > > > On 6/10/20 2:56 AM, Patrick O'Callaghan wrote: > > > > In KVM/QEMU you can also pin specific cores to your VM to prevent > > > > competition between the host and guest (mainly by avoiding cache > > > > pollution as I understand it). > > https://vfio.blogspot.com/2015/05/vfio-gpu-how-to-series-part-4-our-first.html > > > > (search for vcpupin partway down the page). This doesn't relate to NUMA > > systems but to cache efficiency (also mentioned in your second > > reference), though it may be a matter of terminology. Perhaps I should > > have said "avoid" or "mitigate" rather than "prevent". > > I don't see anything there that suggests that CPU affinity is related to > competition between the host and the guest.
It relates to competition in the sense that keeping host and guest to disjoint sets of cores avoids them competing for the same cores and hence contaminating the respective caches. That's all I mean. Don't read too much into it. Clearly the whole set is still being scheduled by the host system. poc _______________________________________________ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org
