Messages in this thread | | | Date | Fri, 4 Aug 2023 13:44:27 +0530 | Subject | Re: [patch V3 23/40] x86/cpu: Provide cpu_init/parse_topology() | From | K Prateek Nayak <> |
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Hello Thomas,
On 8/2/2023 3:51 PM, Thomas Gleixner wrote: > > [..snip..] > > +static void topo_set_max_cores(struct topo_scan *tscan) > +{ > + /* > + * Bug compatible for now. This is broken on hybrid systems: > + * 8 cores SMT + 8 cores w/o SMT > + * tscan.dom_ncpus[TOPO_CORE_DOMAIN] = 24; 24 / 2 = 12 !! > + * > + * Cannot be fixed without further topology enumeration changes. > + */ > + tscan->c->x86_max_cores = tscan->dom_ncpus[TOPO_CORE_DOMAIN] >> > + x86_topo_system.dom_shifts[TOPO_SMT_DOMAIN]; > +} >
In Documentation/arch/x86/topology.rst, "cpuinfo_x86.x86_max_cores" is described as "The number of cores in a package". In which case, shouldn't the above be:
tscan->c->x86_max_cores = tscan->dom_ncpus[TOPO_PKG_DOMAIN] >> x86_topo_system.dom_shifts[TOPO_SMT_DOMAIN];
since, with extended topology, there could be other higher domains and dom_ncpus[TOPO_CORE_DOMAIN] >> dom_shifts[TOPO_SMT_DOMAIN] should only give number of cores within the next domain (TOPO_MODULE_DOMAIN).
Am I missing something here?
-- Thanks and Regards, Prateek
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