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| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2010-08-31 10:28:17 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2010-09-09 20:41:25 +0200 |
| commit | b40d8ed4e42c79f8ed1cf345eed0888f4a2f0678 (patch) | |
| tree | e7bfe98c1cbf21a871fee2c25640898c7b60bcfb /Documentation/cputopology.txt | |
| parent | 01a08546af311c065f34727787dd0cc8dc0c216f (diff) | |
| download | lwn-b40d8ed4e42c79f8ed1cf345eed0888f4a2f0678.tar.gz lwn-b40d8ed4e42c79f8ed1cf345eed0888f4a2f0678.zip | |
topology/sysfs: Provide book id and siblings attributes
Create attributes:
/sys/devices/system/cpu/cpuX/topology/book_id
/sys/devices/system/cpu/cpuX/topology/book_siblings
which show the book id and the book siblings of a cpu.
Unlike the attributes for SMT and MC these attributes are only present if
CONFIG_SCHED_BOOK is set. There is no reason to pollute sysfs for every
architecture with unused attributes.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100831082844.435648457@de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'Documentation/cputopology.txt')
| -rw-r--r-- | Documentation/cputopology.txt | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/Documentation/cputopology.txt b/Documentation/cputopology.txt index f1c5c4bccd3e..902d3151f527 100644 --- a/Documentation/cputopology.txt +++ b/Documentation/cputopology.txt @@ -14,25 +14,39 @@ to /proc/cpuinfo. identifier (rather than the kernel's). The actual value is architecture and platform dependent. -3) /sys/devices/system/cpu/cpuX/topology/thread_siblings: +3) /sys/devices/system/cpu/cpuX/topology/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/thread_siblings: internel kernel map of cpuX's hardware threads within the same core as cpuX -4) /sys/devices/system/cpu/cpuX/topology/core_siblings: +5) /sys/devices/system/cpu/cpuX/topology/core_siblings: internal kernel map of cpuX's hardware threads within the same physical_package_id. +6) /sys/devices/system/cpu/cpuX/topology/book_siblings: + + internal kernel map of cpuX's hardware threads within the same + book_id. + To implement it in an architecture-neutral way, a new source file, -drivers/base/topology.c, is to export the 4 attributes. +drivers/base/topology.c, is to export the 4 or 6 attributes. The two book +related sysfs files will only be created if CONFIG_SCHED_BOOK is selected. 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_core_id(cpu) +#define topology_book_id(cpu) #define topology_thread_cpumask(cpu) #define topology_core_cpumask(cpu) +#define topology_book_cpumask(cpu) The type of **_id is int. The type of siblings is (const) struct cpumask *. @@ -45,6 +59,9 @@ not defined by include/asm-XXX/topology.h: 3) thread_siblings: just the given CPU 4) core_siblings: 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(). + Additionally, CPU topology information is provided under /sys/devices/system/cpu and includes these files. The internal source for the output is in brackets ("[]"). |