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@@ -1,6 +1,6 @@
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Export CPU topology info via sysfs. Items (attributes) are similar
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-to /proc/cpuinfo.
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+to /proc/cpuinfo output of some architectures:
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1) /sys/devices/system/cpu/cpuX/topology/physical_package_id:
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@@ -23,20 +23,35 @@ to /proc/cpuinfo.
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4) /sys/devices/system/cpu/cpuX/topology/thread_siblings:
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internal kernel map of cpuX's hardware threads within the same
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- core as cpuX
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+ core as cpuX.
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-5) /sys/devices/system/cpu/cpuX/topology/core_siblings:
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+5) /sys/devices/system/cpu/cpuX/topology/thread_siblings_list:
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+
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+ human-readable list of cpuX's hardware threads within the same
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+ core as cpuX.
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+
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+6) /sys/devices/system/cpu/cpuX/topology/core_siblings:
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internal kernel map of cpuX's hardware threads within the same
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physical_package_id.
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-6) /sys/devices/system/cpu/cpuX/topology/book_siblings:
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+7) /sys/devices/system/cpu/cpuX/topology/core_siblings_list:
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+
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+ human-readable list of cpuX's hardware threads within the same
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+ physical_package_id.
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+
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+8) /sys/devices/system/cpu/cpuX/topology/book_siblings:
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internal kernel map of cpuX's hardware threads within the same
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book_id.
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+9) /sys/devices/system/cpu/cpuX/topology/book_siblings_list:
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+
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+ human-readable list of cpuX's hardware threads within the same
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+ book_id.
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+
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To implement it in an architecture-neutral way, a new source file,
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-drivers/base/topology.c, is to export the 4 or 6 attributes. The two book
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+drivers/base/topology.c, is to export the 6 or 9 attributes. The three book
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related sysfs files will only be created if CONFIG_SCHED_BOOK is selected.
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For an architecture to support this feature, it must define some of
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@@ -48,16 +63,18 @@ these macros in include/asm-XXX/topology.h:
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#define topology_core_cpumask(cpu)
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#define topology_book_cpumask(cpu)
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-The type of **_id is int.
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-The type of siblings is (const) struct cpumask *.
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+The type of **_id macros is int.
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+The type of **_cpumask macros is (const) struct cpumask *. The latter
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+correspond with appropriate **_siblings sysfs attributes (except for
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+topology_sibling_cpumask() which corresponds with thread_siblings).
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To be consistent on all architectures, include/linux/topology.h
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provides default definitions for any of the above macros that are
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not defined by include/asm-XXX/topology.h:
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1) physical_package_id: -1
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2) core_id: 0
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-3) thread_siblings: just the given CPU
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-4) core_siblings: just the given CPU
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+3) sibling_cpumask: just the given CPU
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+4) core_cpumask: just the given CPU
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For architectures that don't support books (CONFIG_SCHED_BOOK) there are no
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default definitions for topology_book_id() and topology_book_cpumask().
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