69dcc99199
The patch implements cpu topology exportation by sysfs. Items (attributes) are similar to /proc/cpuinfo. 1) /sys/devices/system/cpu/cpuX/topology/physical_package_id: represent the physical package id of cpu X; 2) /sys/devices/system/cpu/cpuX/topology/core_id: represent the cpu core id to cpu X; 3) /sys/devices/system/cpu/cpuX/topology/thread_siblings: represent the thread siblings to cpu X in the same core; 4) /sys/devices/system/cpu/cpuX/topology/core_siblings: represent the thread siblings to cpu X in the same physical package; To implement it in an architecture-neutral way, a new source file, driver/base/topology.c, is to export the 5 attributes. If one architecture wants to support this feature, it just needs to implement 4 defines, typically in file include/asm-XXX/topology.h. The 4 defines are: #define topology_physical_package_id(cpu) #define topology_core_id(cpu) #define topology_thread_siblings(cpu) #define topology_core_siblings(cpu) The type of **_id is int. The type of siblings is cpumask_t. To be consistent on all architectures, the 4 attributes should have deafult values if their values are unavailable. Below is the rule. 1) physical_package_id: If cpu has no physical package id, -1 is the default value. 2) core_id: If cpu doesn't support multi-core, its core id is 0. 3) thread_siblings: Just include itself, if the cpu doesn't support HT/multi-thread. 4) core_siblings: Just include itself, if the cpu doesn't support multi-core and HT/Multi-thread. So be careful when declaring the 4 defines in include/asm-XXX/topology.h. If an attribute isn't defined on an architecture, it won't be exported. Thank Nathan, Greg, Andi, Paul and Venki. The patch provides defines for i386/x86_64/ia64. Signed-off-by: Zhang, Yanmin <yanmin.zhang@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
41 lines
1.6 KiB
Text
41 lines
1.6 KiB
Text
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Export cpu topology info by sysfs. Items (attributes) are similar
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to /proc/cpuinfo.
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1) /sys/devices/system/cpu/cpuX/topology/physical_package_id:
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represent the physical package id of cpu X;
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2) /sys/devices/system/cpu/cpuX/topology/core_id:
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represent the cpu core id to cpu X;
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3) /sys/devices/system/cpu/cpuX/topology/thread_siblings:
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represent the thread siblings to cpu X in the same core;
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4) /sys/devices/system/cpu/cpuX/topology/core_siblings:
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represent the thread siblings to cpu X in the same physical package;
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To implement it in an architecture-neutral way, a new source file,
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driver/base/topology.c, is to export the 5 attributes.
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If one architecture wants to support this feature, it just needs to
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implement 4 defines, typically in file include/asm-XXX/topology.h.
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The 4 defines are:
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#define topology_physical_package_id(cpu)
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#define topology_core_id(cpu)
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#define topology_thread_siblings(cpu)
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#define topology_core_siblings(cpu)
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The type of **_id is int.
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The type of siblings is cpumask_t.
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To be consistent on all architectures, the 4 attributes should have
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deafult values if their values are unavailable. Below is the rule.
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1) physical_package_id: If cpu has no physical package id, -1 is the
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default value.
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2) core_id: If cpu doesn't support multi-core, its core id is 0.
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3) thread_siblings: Just include itself, if the cpu doesn't support
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HT/multi-thread.
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4) core_siblings: Just include itself, if the cpu doesn't support
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multi-core and HT/Multi-thread.
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So be careful when declaring the 4 defines in include/asm-XXX/topology.h.
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If an attribute isn't defined on an architecture, it won't be exported.
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