Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [patch V4 24/41] x86/cpu: Provide cpu_init/parse_topology() | Date | Mon, 28 Aug 2023 12:05:03 +0200 |
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Prateek!
On Mon, Aug 28 2023 at 11:37, K. Prateek Nayak wrote: > On 8/14/2023 2:24 PM, Thomas Gleixner wrote: > > Since these enums come from the description of level type of CPUID leaf > 0x1f, can we have a short description clarifying what each signify. This > will also help clarify the mappings for AMD's extended CPUID leaf > 0x80000026 (specifically for CCX and CCD level types). I had following > in my mind:
Makes sense.
> TOPO_MODULE_DOMAIN, > + /* > + * If exists, represents a group of tiles within > + * an instance of the next domain > + * > + * On Intel: This level contains a group of Tile > + * type as described by CPUID leaf 0x1f > + * > + * On AMD: This is the group of "Complex" type > + * instances as described by CPUID leaf > + * 0x8000_0026 > + */ > TOPO_TILE_DOMAIN, > + /* > + * If exists, represents a group of dies within an > + * instance of the next domain > + * > + * On Intel: This level contains group of Die > + * type as described by CPUID leaf 0x1f > + * > + * On AMD: This is the group of "CCD (Die)" > + * type instances as described by CPUID leaf > + * 0x8000_0026 > + */ > TOPO_DIE_DOMAIN, > + /* > + * If exists, represents a group of packages > + * within the root domain > + */ > TOPO_PKG_DOMAIN, > + /* Topmost domain with a singular instance */ > TOPO_ROOT_DOMAIN, > TOPO_MAX_DOMAIN, > };
Now this begs the obvious question what the actual meaning of these domains is and what's their relevance for the kernel.
It's probably undisputed what SMT/CORE mean and what their relevance is. The PKG/DIE domains are pretty clear too.
Now we have:
MODULE (Intel only)
TILE Intel, AMD names it "Complex"
So here are the questions:
- is TILE to "Complex" the proper mapping?
- which information is conveyed by MODULE and TILE?
- Are these really different between AMD and Intel or is this some naming convention issue which needs to be resolved?
Thanks,
tglx
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