Commit e7849f16 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'core/topology' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 

* 'core/topology' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  cputopology: always define CPU topology information, clean up
  cpu topology: always define CPU topology information
parents af5329cd 131b943a

Documentation/cputopology.txt

+9 −17
Original line number Diff line number Diff line
@@ -14,9 +14,8 @@ represent the thread siblings to cpu X in the same physical package; 
To implement it in an architecture-neutral way, a new source file,

drivers/base/topology.c, is to export the 4 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:

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_thread_siblings(cpu)
@@ -25,17 +24,10 @@ The 4 defines are: 
The type of **_id is int.

The type of siblings is cpumask_t.



To be consistent on all architectures, the 4 attributes should have

default 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.

To be consistent on all architectures, include/linux/topology.h

provides default definitions for any of the above macros that are

not defined by include/asm-XXX/topology.h:

1) physical_package_id: -1

2) core_id: 0

3) thread_siblings: just the given CPU

4) core_siblings: just the given CPU

drivers/base/topology.c

+6 −26
Original line number Diff line number Diff line
@@ -93,47 +93,27 @@ static ssize_t show_##name##_list(struct sys_device *dev, char *buf) \ 
#define define_siblings_show_func(name)		\

	define_siblings_show_map(name); define_siblings_show_list(name)



#ifdef	topology_physical_package_id

define_id_show_func(physical_package_id);

define_one_ro(physical_package_id);

#define ref_physical_package_id_attr	&attr_physical_package_id.attr,

#else

#define ref_physical_package_id_attr

#endif



#ifdef topology_core_id

define_id_show_func(core_id);

define_one_ro(core_id);

#define ref_core_id_attr		&attr_core_id.attr,

#else

#define ref_core_id_attr

#endif



#ifdef topology_thread_siblings

define_siblings_show_func(thread_siblings);

define_one_ro(thread_siblings);

define_one_ro(thread_siblings_list);

#define ref_thread_siblings_attr	\

		&attr_thread_siblings.attr, &attr_thread_siblings_list.attr,

#else

#define ref_thread_siblings_attr

#endif



#ifdef topology_core_siblings

define_siblings_show_func(core_siblings);

define_one_ro(core_siblings);

define_one_ro(core_siblings_list);

#define ref_core_siblings_attr		\

		&attr_core_siblings.attr, &attr_core_siblings_list.attr,

#else

#define ref_core_siblings_attr

#endif



static struct attribute *default_attrs[] = {

	ref_physical_package_id_attr

	ref_core_id_attr

	ref_thread_siblings_attr

	ref_core_siblings_attr

	&attr_physical_package_id.attr,

	&attr_core_id.attr,

	&attr_thread_siblings.attr,

	&attr_thread_siblings_list.attr,

	&attr_core_siblings.attr,

	&attr_core_siblings_list.attr,

	NULL

};

include/linux/topology.h

+13 −0
Original line number Diff line number Diff line
@@ -179,4 +179,17 @@ void arch_update_cpu_topology(void); 
#endif

#endif /* CONFIG_NUMA */



#ifndef topology_physical_package_id

#define topology_physical_package_id(cpu)	((void)(cpu), -1)

#endif

#ifndef topology_core_id

#define topology_core_id(cpu)			((void)(cpu), 0)

#endif

#ifndef topology_thread_siblings

#define topology_thread_siblings(cpu)		cpumask_of_cpu(cpu)

#endif

#ifndef topology_core_siblings

#define topology_core_siblings(cpu)		cpumask_of_cpu(cpu)

#endif



#endif /* _LINUX_TOPOLOGY_H */