Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

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

	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

	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

	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,

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

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

#define topology_physical_package_id(cpu)

#define topology_core_id(cpu)

#define topology_book_id(cpu)

#define topology_thread_cpumask(cpu)

#define topology_core_cpumask(cpu)

#define topology_book_cpumask(cpu)



The type of **_id is int.

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

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

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

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

drivers/base/topology.c

+15 −1
Original line number 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));	\

}



#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)

{

	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_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[] = {

	&attr_physical_package_id.attr,

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

	&attr_core_siblings.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

};