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Diffstat (limited to 'Documentation/admin-guide/cputopology.rst')
| -rw-r--r-- | Documentation/admin-guide/cputopology.rst | 124 |
1 files changed, 24 insertions, 100 deletions
diff --git a/Documentation/admin-guide/cputopology.rst b/Documentation/admin-guide/cputopology.rst index b90dafcc8237..d29cacc9b3c3 100644 --- a/Documentation/admin-guide/cputopology.rst +++ b/Documentation/admin-guide/cputopology.rst @@ -2,105 +2,28 @@ How CPU topology info is exported via sysfs =========================================== -Export CPU topology info via sysfs. Items (attributes) are similar -to /proc/cpuinfo output of some architectures. They reside in -/sys/devices/system/cpu/cpuX/topology/: - -physical_package_id: - - physical package id of cpuX. Typically corresponds to a physical - socket number, but the actual value is architecture and platform - dependent. - -die_id: - - the CPU die ID of cpuX. Typically it is the hardware platform's - identifier (rather than the kernel's). The actual value is - architecture and platform dependent. - -core_id: - - the CPU core ID of cpuX. Typically it is the hardware platform's - identifier (rather than the kernel's). The actual value is - architecture and platform dependent. - -book_id: - - the book ID of cpuX. Typically it is the hardware platform's - identifier (rather than the kernel's). The actual value is - architecture and platform dependent. - -drawer_id: - - the drawer ID of cpuX. Typically it is the hardware platform's - identifier (rather than the kernel's). The actual value is - architecture and platform dependent. - -core_cpus: - - internal kernel map of CPUs within the same core. - (deprecated name: "thread_siblings") - -core_cpus_list: - - human-readable list of CPUs within the same core. - (deprecated name: "thread_siblings_list"); - -package_cpus: - - internal kernel map of the CPUs sharing the same physical_package_id. - (deprecated name: "core_siblings") - -package_cpus_list: - - human-readable list of CPUs sharing the same physical_package_id. - (deprecated name: "core_siblings_list") - -die_cpus: - - internal kernel map of CPUs within the same die. - -die_cpus_list: - - human-readable list of CPUs within the same die. - -book_siblings: - - internal kernel map of cpuX's hardware threads within the same - book_id. - -book_siblings_list: - - human-readable list of cpuX's hardware threads within the same - book_id. - -drawer_siblings: - - internal kernel map of cpuX's hardware threads within the same - drawer_id. - -drawer_siblings_list: - - human-readable list of cpuX's hardware threads within the same - drawer_id. +CPU topology info is exported via sysfs. Items (attributes) are similar +to /proc/cpuinfo output of some architectures. They reside in +/sys/devices/system/cpu/cpuX/topology/. Please refer to the ABI file: +Documentation/ABI/stable/sysfs-devices-system-cpu. Architecture-neutral, drivers/base/topology.c, exports these attributes. -However, the book and drawer related sysfs files will only be created if -CONFIG_SCHED_BOOK and CONFIG_SCHED_DRAWER are selected, respectively. - -CONFIG_SCHED_BOOK and CONFIG_SCHED_DRAWER are currently only used on s390, -where they reflect the cpu and cache hierarchy. +However the die, cluster, book, and drawer hierarchy related sysfs files will +only be created if an architecture provides the related macros as described +below. For an architecture to support this feature, it must define some of these macros in include/asm-XXX/topology.h:: #define topology_physical_package_id(cpu) #define topology_die_id(cpu) + #define topology_cluster_id(cpu) #define topology_core_id(cpu) #define topology_book_id(cpu) #define topology_drawer_id(cpu) #define topology_sibling_cpumask(cpu) #define topology_core_cpumask(cpu) + #define topology_cluster_cpumask(cpu) #define topology_die_cpumask(cpu) #define topology_book_cpumask(cpu) #define topology_drawer_cpumask(cpu) @@ -116,15 +39,16 @@ not defined by include/asm-XXX/topology.h: 1) topology_physical_package_id: -1 2) topology_die_id: -1 -3) topology_core_id: 0 -4) topology_sibling_cpumask: just the given CPU -5) topology_core_cpumask: just the given CPU -6) topology_die_cpumask: just the given CPU - -For architectures that don't support books (CONFIG_SCHED_BOOK) there are no -default definitions for topology_book_id() and topology_book_cpumask(). -For architectures that don't support drawers (CONFIG_SCHED_DRAWER) there are -no default definitions for topology_drawer_id() and topology_drawer_cpumask(). +3) topology_cluster_id: -1 +4) topology_core_id: 0 +5) topology_book_id: -1 +6) topology_drawer_id: -1 +7) topology_sibling_cpumask: just the given CPU +8) topology_core_cpumask: just the given CPU +9) topology_cluster_cpumask: just the given CPU +10) topology_die_cpumask: just the given CPU +11) topology_book_cpumask: just the given CPU +12) topology_drawer_cpumask: just the given CPU Additionally, CPU topology information is provided under /sys/devices/system/cpu and includes these files. The internal @@ -135,9 +59,9 @@ source for the output is in brackets ("[]"). [NR_CPUS-1] offline: CPUs that are not online because they have been - HOTPLUGGED off (see cpu-hotplug.txt) or exceed the limit - of CPUs allowed by the kernel configuration (kernel_max - above). [~cpu_online_mask + cpus >= NR_CPUS] + HOTPLUGGED off or exceed the limit of CPUs allowed by the + kernel configuration (kernel_max above). + [~cpu_online_mask + cpus >= NR_CPUS] online: CPUs that are online and being scheduled [cpu_online_mask] @@ -173,5 +97,5 @@ online.):: possible: 0-127 present: 0-3 -See cpu-hotplug.txt for the possible_cpus=NUM kernel start parameter -as well as more information on the various cpumasks. +See Documentation/core-api/cpu_hotplug.rst for the possible_cpus=NUM +kernel start parameter as well as more information on the various cpumasks. |