----- Original Message ----- > From: "Martin Polednik" <[email protected]> > To: [email protected] > Sent: Thursday, December 10, 2015 4:07:57 PM > Subject: [ovirt-devel] CPU sockets, threads, cores and NUMA
> It does fail to provide us with information that can be used in > ppc64le environment, where for POWER8 we want to run the host without > SMT while VMs would have multiple CPUs assigned. There are various > configurations of so-called subcores in POWER8, where each CPU core > can contain 1, 2 or 4 subcores. What are those subcores? Does this subcore concept map on something like SMT on x86_64? Or is this an hardware concept (mind goes to the AMD's bulldozer modules) > This configuration must be taken in > consideration as given e.g. 160 threads overall, it is possible to run > either 20 VMs in smt8 mode, 40 VMs in smt4 mode or 80 VMs in smt2 > mode. Could you elaborate a bit more about the se smtX modes and how they play with threads and cores? > We have to report either the total number of threads OR just the > threadsPerCore setting, so the users know how many "CPUs" should be > assigned to machines for optimal performance. Which options is best for ppc, if there is any difference? bests, -- Francesco Romani RedHat Engineering Virtualization R & D Phone: 8261328 IRC: fromani _______________________________________________ Devel mailing list [email protected] http://lists.ovirt.org/mailman/listinfo/devel
