]> pilppa.com Git - linux-2.6-omap-h63xx.git/commit
[PATCH] Export cpu topology in sysfs
authorZhang, Yanmin <yanmin.zhang@intel.com>
Fri, 3 Feb 2006 11:04:36 +0000 (03:04 -0800)
committerLinus Torvalds <torvalds@g5.osdl.org>
Fri, 3 Feb 2006 16:32:09 +0000 (08:32 -0800)
commit69dcc99199fe29b0a29471a3488d39d9d33b25fc
tree4232ad9a782dee6abfe7fa20c95a49249195de8f
parent66ac5a294db70aa377c0d7bbdb0c4e3ef2349b7b
[PATCH] Export cpu topology in sysfs

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>
Documentation/cputopology.txt [new file with mode: 0644]
arch/ia64/kernel/topology.c
drivers/base/Makefile
drivers/base/topology.c [new file with mode: 0644]
include/asm-i386/topology.h
include/asm-ia64/topology.h
include/asm-x86_64/topology.h