63edbaa48a
On AMD processors that support extended CPUID leaf 0x80000026, use the extended leaf to parse the topology information. In case of a failure, fall back to parsing the information from CPUID leaf 0xb. CPUID leaf 0x80000026 exposes the "CCX" and "CCD (Die)" information on AMD processors which have been mapped to TOPO_TILE_DOMAIN and TOPO_DIE_DOMAIN respectively. Since this information was previously not available via CPUID leaf 0xb or 0x8000001e, the "die_id", "logical_die_id", "max_die_per_pkg", "die_cpus", and "die_cpus_list" will differ with this addition on AMD processors that support extended CPUID leaf 0x80000026 and contain more than one "CCD (Die)" on the package. For example, following are the changes in the values reported by "/sys/kernel/debug/x86/topo/cpus/16" after applying this patch on a 4th Generation AMD EPYC System (1 x 128C/256T): (CPU16 is the first CPU of the second CCD on the package) tip:x86/apic tip:x86/apic + this patch online: 1 1 initial_apicid: 80 80 apicid: 80 80 pkg_id: 0 0 die_id: 0 4 * cu_id: 255 255 core_id: 64 64 logical_pkg_id: 0 0 logical_die_id: 0 4 * llc_id: 8 8 l2c_id: 65535 65535 amd_node_id: 0 0 amd_nodes_per_pkg: 1 1 num_threads: 256 256 num_cores: 128 128 max_dies_per_pkg: 1 8 * max_threads_per_core:2 2 [ prateek: commit log, updated comment in topoext_amd.c, changed has_0xb to has_topoext, rebased the changes on tip:x86/apic, tested the changes on 4th Gen AMD EPYC system ] [ mingo: tidy up the changelog a bit more ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20240314050432.1710-1-kprateek.nayak@amd.com |
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| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the ReStructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.