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Commit b40d8ed4 authored by Heiko Carstens's avatar Heiko Carstens Committed by Ingo Molnar
Browse files

topology/sysfs: Provide book id and siblings attributes 



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: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100831082844.435648457@de.ibm.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 01a08546

Documentation/cputopology.txt

+20 −3
Original line number Original line Diff line number Diff line
@@ -14,25 +14,39 @@ to /proc/cpuinfo. 
	identifier (rather than the kernel's).  The actual value is

	identifier (rather than the kernel's).  The actual value is

	architecture and platform dependent.

	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

	internel kernel map of cpuX's hardware threads within the same

	core as cpuX

	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

	internal kernel map of cpuX's hardware threads within the same

	physical_package_id.

	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,

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

For an architecture to support this feature, it must define some of

these macros in include/asm-XXX/topology.h:

these macros in include/asm-XXX/topology.h:

#define topology_physical_package_id(cpu)

#define topology_physical_package_id(cpu)

#define topology_core_id(cpu)

#define topology_core_id(cpu)

#define topology_book_id(cpu)

#define topology_thread_cpumask(cpu)

#define topology_thread_cpumask(cpu)

#define topology_core_cpumask(cpu)

#define topology_core_cpumask(cpu)

#define topology_book_cpumask(cpu)





The type of **_id is int.

The type of **_id is int.

The type of siblings is (const) struct cpumask *.

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

3) thread_siblings: just the given CPU

4) core_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

Additionally, CPU topology information is provided under

/sys/devices/system/cpu and includes these files.  The internal

/sys/devices/system/cpu and includes these files.  The internal

source for the output is in brackets ("[]").

source for the output is in brackets ("[]").

drivers/base/topology.c

+15 −1
Original line number Original line Diff line number Diff line
@@ -45,7 +45,8 @@ static ssize_t show_##name(struct sys_device *dev, \ 
	return sprintf(buf, "%d\n", topology_##name(cpu));	\

	return sprintf(buf, "%d\n", topology_##name(cpu));	\

}

}





#if defined(topology_thread_cpumask) || defined(topology_core_cpumask)

#if defined(topology_thread_cpumask) || defined(topology_core_cpumask) || \

    defined(topology_book_cpumask)

static ssize_t show_cpumap(int type, const struct cpumask *mask, char *buf)

static ssize_t show_cpumap(int type, const struct cpumask *mask, char *buf)

{

{

	ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf;

	ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf;
@@ -114,6 +115,14 @@ define_siblings_show_func(core_cpumask); 
define_one_ro_named(core_siblings, show_core_cpumask);

define_one_ro_named(core_siblings, show_core_cpumask);

define_one_ro_named(core_siblings_list, show_core_cpumask_list);

define_one_ro_named(core_siblings_list, show_core_cpumask_list);





#ifdef CONFIG_SCHED_BOOK

define_id_show_func(book_id);

define_one_ro(book_id);

define_siblings_show_func(book_cpumask);

define_one_ro_named(book_siblings, show_book_cpumask);

define_one_ro_named(book_siblings_list, show_book_cpumask_list);

#endif



static struct attribute *default_attrs[] = {

static struct attribute *default_attrs[] = {

	&attr_physical_package_id.attr,

	&attr_physical_package_id.attr,

	&attr_core_id.attr,

	&attr_core_id.attr,
@@ -121,6 +130,11 @@ static struct attribute *default_attrs[] = { 
	&attr_thread_siblings_list.attr,

	&attr_thread_siblings_list.attr,

	&attr_core_siblings.attr,

	&attr_core_siblings.attr,

	&attr_core_siblings_list.attr,

	&attr_core_siblings_list.attr,

#ifdef CONFIG_SCHED_BOOK

	&attr_book_id.attr,

	&attr_book_siblings.attr,

	&attr_book_siblings_list.attr,

#endif

	NULL

	NULL

};

};