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topology/sysfs: Provide book id and siblings attributes

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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>
This commit is contained in:
Heiko Carstens
2010-08-31 10:28:17 +02:00
committed by Ingo Molnar
parent 01a08546af
commit b40d8ed4e4
2 changed files with 35 additions and 4 deletions
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Documentation/cputopology.txt
+20 -3
View File
@@ -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 ("[]").