Skip to content

Commit

Permalink
Merge branch 'core/topology' of git://git.kernel.org/pub/scm/linux/ke…
Browse files Browse the repository at this point in the history
…rnel/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
  • Loading branch information
Linus Torvalds committed Jul 15, 2008
2 parents af5329c + 131b943 commit e7849f1
Show file tree
Hide file tree
Showing 3 changed files with 28 additions and 43 deletions.
26 changes: 9 additions & 17 deletions Documentation/cputopology.txt
Original file line number Diff line number Diff line change
Expand Up @@ -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)
Expand All @@ -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
32 changes: 6 additions & 26 deletions drivers/base/topology.c
Original file line number Diff line number Diff line change
Expand Up @@ -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
};

Expand Down
13 changes: 13 additions & 0 deletions include/linux/topology.h
Original file line number Diff line number Diff line change
Expand Up @@ -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 */

0 comments on commit e7849f1

Please sign in to comment.