linux/drivers/base
Zhang, Yanmin 69dcc99199 [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>
2006-02-03 08:32:09 -08:00
..
power [PATCH] device_shutdown can loop if the driver frees itself 2006-01-13 11:26:12 -08:00
attribute_container.c
base.h
bus.c
class.c
core.c [PATCH] DocBook: fix kernel-doc comments 2006-01-10 08:01:53 -08:00
cpu.c [PATCH] kdump: export per cpu crash notes pointer through sysfs (fix) 2006-01-10 08:01:26 -08:00
dd.c [PATCH] Add bus_type probe, remove, shutdown methods. 2006-01-13 11:26:04 -08:00
dmapool.c
driver.c [PATCH] Add bus_type probe, remove, shutdown methods. 2006-01-13 11:26:04 -08:00
firmware_class.c [PATCH] Unlinline a bunch of other functions 2006-01-14 18:27:06 -08:00
firmware.c
init.c
Kconfig
Makefile [PATCH] Export cpu topology in sysfs 2006-02-03 08:32:09 -08:00
map.c
memory.c [PATCH] move capable() to capability.h 2006-01-11 18:42:13 -08:00
node.c
platform.c [PATCH] platform-device-del typo fix 2006-01-13 11:26:11 -08:00
sys.c
topology.c [PATCH] Export cpu topology in sysfs 2006-02-03 08:32:09 -08:00
transport_class.c