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Diffstat (limited to 'Documentation/cputopology.txt')
| -rw-r--r-- | Documentation/cputopology.txt | 46 |
1 files changed, 23 insertions, 23 deletions
diff --git a/Documentation/cputopology.txt b/Documentation/cputopology.txt index c6e7e9196a8b..cb61277e2308 100644 --- a/Documentation/cputopology.txt +++ b/Documentation/cputopology.txt @@ -3,79 +3,79 @@ 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: +to /proc/cpuinfo output of some architectures. They reside in +/sys/devices/system/cpu/cpuX/topology/: -1) /sys/devices/system/cpu/cpuX/topology/physical_package_id: +physical_package_id: physical package id of cpuX. Typically corresponds to a physical socket number, but the actual value is architecture and platform dependent. -2) /sys/devices/system/cpu/cpuX/topology/core_id: +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. -3) /sys/devices/system/cpu/cpuX/topology/book_id: +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. -4) /sys/devices/system/cpu/cpuX/topology/drawer_id: +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. -5) /sys/devices/system/cpu/cpuX/topology/thread_siblings: +thread_siblings: internal kernel map of cpuX's hardware threads within the same core as cpuX. -6) /sys/devices/system/cpu/cpuX/topology/thread_siblings_list: +thread_siblings_list: human-readable list of cpuX's hardware threads within the same core as cpuX. -7) /sys/devices/system/cpu/cpuX/topology/core_siblings: +core_siblings: internal kernel map of cpuX's hardware threads within the same physical_package_id. -8) /sys/devices/system/cpu/cpuX/topology/core_siblings_list: +core_siblings_list: human-readable list of cpuX's hardware threads within the same physical_package_id. -9) /sys/devices/system/cpu/cpuX/topology/book_siblings: +book_siblings: internal kernel map of cpuX's hardware threads within the same book_id. -10) /sys/devices/system/cpu/cpuX/topology/book_siblings_list: +book_siblings_list: human-readable list of cpuX's hardware threads within the same book_id. -11) /sys/devices/system/cpu/cpuX/topology/drawer_siblings: +drawer_siblings: internal kernel map of cpuX's hardware threads within the same drawer_id. -12) /sys/devices/system/cpu/cpuX/topology/drawer_siblings_list: +drawer_siblings_list: human-readable list of cpuX's hardware threads within the same drawer_id. -To implement it in an architecture-neutral way, a new source file, -drivers/base/topology.c, is to export the 6 to 12 attributes. The book -and drawer related sysfs files will only be created if CONFIG_SCHED_BOOK -and CONFIG_SCHED_DRAWER are selected. +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_DRAWER are currently only used on s390, where -they reflect the cpu and cache hierarchy. +CONFIG_SCHED_BOOK and CONFIG_SCHED_DRAWER are currently only used on s390, +where they reflect the cpu and cache hierarchy. For an architecture to support this feature, it must define some of these macros in include/asm-XXX/topology.h:: @@ -98,10 +98,10 @@ To be consistent on all architectures, include/linux/topology.h provides default definitions for any of the above macros that are not defined by include/asm-XXX/topology.h: -1) physical_package_id: -1 -2) core_id: 0 -3) sibling_cpumask: just the given CPU -4) core_cpumask: just the given CPU +1) topology_physical_package_id: -1 +2) topology_core_id: 0 +3) topology_sibling_cpumask: just the given CPU +4) topology_core_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(). |