[PATCH 0/3] topology/sysfs: only export used sysfs attributes

[PATCH 0/3] topology/sysfs: only export used sysfs attributes

[Heiko Carstens]

Create die and cluster cpu topology sysfs attributes only if an
architecture makes uses of it, instead of creating them always for all
architectures with bogus default values.
Also change the book and drawer cpu topology macros so they match all
all other topology macros.

Heiko Carstens (3):
  topology/sysfs: export die attributes only if an architectures has support
  topology/sysfs: export cluster attributes only if an architectures has support
  topology/sysfs: rework book and drawer topology ifdefery

 Documentation/admin-guide/cputopology.rst | 33 +++++++++++------------
 drivers/base/topology.c                   | 28 ++++++++++++++-----
 include/linux/topology.h                  | 20 ++++++++++++++
 3 files changed, 57 insertions(+), 24 deletions(-)

-- 
2.32.0

[PATCH 1/3] topology/sysfs: export die attributes only if an architectures has support

[Heiko Carstens]

The die_id and die_cpus topology sysfs attributes have been added with
commit 0e344d8c709f ("cpu/topology: Export die_id") and commit
2e4c54dac7b3 ("topology: Create core_cpus and die_cpus sysfs attributes").

While they are currently only used and useful for x86 they are still
present with bogus default values for all architectures. Instead of
enforcing such new sysfs attributes to all architectures, make them
only optional visible if an architecture opts in by defining both the
topology_die_id and topology_die_cpumask attributes.

This is similar to what was done when the book and drawer topology
levels were introduced: avoid useless and therefore confusing sysfs
attributes for architectures which cannot make use of them.

This should not break any existing applications, since this is a
rather new interface and applications should be able to handle also
older kernel versions without such attributes - besides that they
contain only useful information for x86.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
---
 Documentation/admin-guide/cputopology.rst | 3 +++
 drivers/base/topology.c                   | 8 ++++++++
 include/linux/topology.h                  | 2 ++
 3 files changed, 13 insertions(+)

diff --git a/Documentation/admin-guide/cputopology.rst b/Documentation/admin-guide/cputopology.rst
index 6b62e182baf4..c68d07533c45 100644
--- a/Documentation/admin-guide/cputopology.rst
+++ b/Documentation/admin-guide/cputopology.rst
@@ -11,6 +11,9 @@ Architecture-neutral, drivers/base/topology.c, exports these attributes.
 However, the book and drawer related sysfs files will only be created if
 CONFIG_SCHED_BOOK and CONFIG_SCHED_DRAWER are selected, respectively.
 
+The die hierarchy related sysfs files will only be created if an architecture
+provides the related macros as described below.
+
 CONFIG_SCHED_BOOK and CONFIG_SCHED_DRAWER are currently only used on s390,
 where they reflect the cpu and cache hierarchy.
 
diff --git a/drivers/base/topology.c b/drivers/base/topology.c
index 8f2b641d0b8c..7fa5a7fbef25 100644
--- a/drivers/base/topology.c
+++ b/drivers/base/topology.c
@@ -45,8 +45,10 @@ static ssize_t name##_list_read(struct file *file, struct kobject *kobj,	\
 define_id_show_func(physical_package_id);
 static DEVICE_ATTR_RO(physical_package_id);
 
+#ifndef topology_die_no_sysfs
 define_id_show_func(die_id);
 static DEVICE_ATTR_RO(die_id);
+#endif
 
 define_id_show_func(cluster_id);
 static DEVICE_ATTR_RO(cluster_id);
@@ -70,9 +72,11 @@ define_siblings_read_func(cluster_cpus, cluster_cpumask);
 static BIN_ATTR_RO(cluster_cpus, 0);
 static BIN_ATTR_RO(cluster_cpus_list, 0);
 
+#ifndef topology_die_no_sysfs
 define_siblings_read_func(die_cpus, die_cpumask);
 static BIN_ATTR_RO(die_cpus, 0);
 static BIN_ATTR_RO(die_cpus_list, 0);
+#endif
 
 define_siblings_read_func(package_cpus, core_cpumask);
 static BIN_ATTR_RO(package_cpus, 0);
@@ -103,8 +107,10 @@ static struct bin_attribute *bin_attrs[] = {
 	&bin_attr_core_siblings_list,
 	&bin_attr_cluster_cpus,
 	&bin_attr_cluster_cpus_list,
+#ifndef topology_die_no_sysfs
 	&bin_attr_die_cpus,
 	&bin_attr_die_cpus_list,
+#endif
 	&bin_attr_package_cpus,
 	&bin_attr_package_cpus_list,
 #ifdef CONFIG_SCHED_BOOK
@@ -120,7 +126,9 @@ static struct bin_attribute *bin_attrs[] = {
 
 static struct attribute *default_attrs[] = {
 	&dev_attr_physical_package_id.attr,
+#ifndef topology_die_no_sysfs
 	&dev_attr_die_id.attr,
+#endif
 	&dev_attr_cluster_id.attr,
 	&dev_attr_core_id.attr,
 #ifdef CONFIG_SCHED_BOOK
diff --git a/include/linux/topology.h b/include/linux/topology.h
index 0b3704ad13c8..1541d210be24 100644
--- a/include/linux/topology.h
+++ b/include/linux/topology.h
@@ -185,6 +185,7 @@ static inline int cpu_to_mem(int cpu)
 #endif
 #ifndef topology_die_id
 #define topology_die_id(cpu)			((void)(cpu), -1)
+#define topology_die_no_sysfs			1
 #endif
 #ifndef topology_cluster_id
 #define topology_cluster_id(cpu)		((void)(cpu), -1)
@@ -203,6 +204,7 @@ static inline int cpu_to_mem(int cpu)
 #endif
 #ifndef topology_die_cpumask
 #define topology_die_cpumask(cpu)		cpumask_of(cpu)
+#define topology_die_no_sysfs			1
 #endif
 
 #if defined(CONFIG_SCHED_SMT) && !defined(cpu_smt_mask)
-- 
2.32.0

Re: [PATCH 1/3] topology/sysfs: export die attributes only if an architectures has support

[Greg Kroah-Hartman]

On Sun, Nov 28, 2021 at 10:22:19PM +0100, Heiko Carstens wrote:
> The die_id and die_cpus topology sysfs attributes have been added with
> commit 0e344d8c709f ("cpu/topology: Export die_id") and commit
> 2e4c54dac7b3 ("topology: Create core_cpus and die_cpus sysfs attributes").
> 
> While they are currently only used and useful for x86 they are still
> present with bogus default values for all architectures. Instead of
> enforcing such new sysfs attributes to all architectures, make them
> only optional visible if an architecture opts in by defining both the
> topology_die_id and topology_die_cpumask attributes.
> 
> This is similar to what was done when the book and drawer topology
> levels were introduced: avoid useless and therefore confusing sysfs
> attributes for architectures which cannot make use of them.
> 
> This should not break any existing applications, since this is a
> rather new interface and applications should be able to handle also
> older kernel versions without such attributes - besides that they
> contain only useful information for x86.
> 
> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
> ---
>  Documentation/admin-guide/cputopology.rst | 3 +++
>  drivers/base/topology.c                   | 8 ++++++++
>  include/linux/topology.h                  | 2 ++
>  3 files changed, 13 insertions(+)
> 
> diff --git a/Documentation/admin-guide/cputopology.rst b/Documentation/admin-guide/cputopology.rst
> index 6b62e182baf4..c68d07533c45 100644
> --- a/Documentation/admin-guide/cputopology.rst
> +++ b/Documentation/admin-guide/cputopology.rst
> @@ -11,6 +11,9 @@ Architecture-neutral, drivers/base/topology.c, exports these attributes.
>  However, the book and drawer related sysfs files will only be created if
>  CONFIG_SCHED_BOOK and CONFIG_SCHED_DRAWER are selected, respectively.
>  
> +The die hierarchy related sysfs files will only be created if an architecture
> +provides the related macros as described below.
> +
>  CONFIG_SCHED_BOOK and CONFIG_SCHED_DRAWER are currently only used on s390,
>  where they reflect the cpu and cache hierarchy.
>  
> diff --git a/drivers/base/topology.c b/drivers/base/topology.c
> index 8f2b641d0b8c..7fa5a7fbef25 100644
> --- a/drivers/base/topology.c
> +++ b/drivers/base/topology.c
> @@ -45,8 +45,10 @@ static ssize_t name##_list_read(struct file *file, struct kobject *kobj,	\
>  define_id_show_func(physical_package_id);
>  static DEVICE_ATTR_RO(physical_package_id);
>  
> +#ifndef topology_die_no_sysfs

Please flip this #define around to be the other way:
	TOPOLOGY_DIE_SYSFS
and enable/disable it.

Makes it much easier to understand than "negative logic"

Also, defines need to be all uppercase.

thanks,

greg k-h

[PATCH 2/3] topology/sysfs: export cluster attributes only if an architectures has support

[Heiko Carstens]

The cluster_id and cluster_cpus topology sysfs attributes have been
added with c5e22feffdd7 ("topology: Represent clusters of CPUs within
a die").

They are currently only used for x86, arm64, and riscv (via generic
arch topology), however they are still present with bogus default
values for all other architectures. Instead of enforcing such new
sysfs attributes to all architectures, make them only optional visible
if an architecture opts in by defining both the topology_cluster_id
and topology_cluster_cpumask attributes.

This is similar to what was done when the book and drawer topology
levels were introduced: avoid useless and therefore confusing sysfs
attributes for architectures which cannot make use of them.

This should not break any existing applications, since this is a
new interface introduced with the v5.16 merge window.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
---
 Documentation/admin-guide/cputopology.rst | 4 ++--
 drivers/base/topology.c                   | 8 ++++++++
 include/linux/topology.h                  | 2 ++
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/Documentation/admin-guide/cputopology.rst b/Documentation/admin-guide/cputopology.rst
index c68d07533c45..ad2238b41439 100644
--- a/Documentation/admin-guide/cputopology.rst
+++ b/Documentation/admin-guide/cputopology.rst
@@ -11,8 +11,8 @@ Architecture-neutral, drivers/base/topology.c, exports these attributes.
 However, the book and drawer related sysfs files will only be created if
 CONFIG_SCHED_BOOK and CONFIG_SCHED_DRAWER are selected, respectively.
 
-The die hierarchy related sysfs files will only be created if an architecture
-provides the related macros as described below.
+The die and cluster hierarchy related sysfs files will only be created if an
+architecture provides the related macros as described below.
 
 CONFIG_SCHED_BOOK and CONFIG_SCHED_DRAWER are currently only used on s390,
 where they reflect the cpu and cache hierarchy.
diff --git a/drivers/base/topology.c b/drivers/base/topology.c
index 7fa5a7fbef25..1a288eac2c44 100644
--- a/drivers/base/topology.c
+++ b/drivers/base/topology.c
@@ -50,8 +50,10 @@ define_id_show_func(die_id);
 static DEVICE_ATTR_RO(die_id);
 #endif
 
+#ifndef topology_cluster_no_sysfs
 define_id_show_func(cluster_id);
 static DEVICE_ATTR_RO(cluster_id);
+#endif
 
 define_id_show_func(core_id);
 static DEVICE_ATTR_RO(core_id);
@@ -68,9 +70,11 @@ define_siblings_read_func(core_siblings, core_cpumask);
 static BIN_ATTR_RO(core_siblings, 0);
 static BIN_ATTR_RO(core_siblings_list, 0);
 
+#ifndef topology_cluster_no_sysfs
 define_siblings_read_func(cluster_cpus, cluster_cpumask);
 static BIN_ATTR_RO(cluster_cpus, 0);
 static BIN_ATTR_RO(cluster_cpus_list, 0);
+#endif
 
 #ifndef topology_die_no_sysfs
 define_siblings_read_func(die_cpus, die_cpumask);
@@ -105,8 +109,10 @@ static struct bin_attribute *bin_attrs[] = {
 	&bin_attr_thread_siblings_list,
 	&bin_attr_core_siblings,
 	&bin_attr_core_siblings_list,
+#ifndef topology_cluster_no_sysfs
 	&bin_attr_cluster_cpus,
 	&bin_attr_cluster_cpus_list,
+#endif
 #ifndef topology_die_no_sysfs
 	&bin_attr_die_cpus,
 	&bin_attr_die_cpus_list,
@@ -129,7 +135,9 @@ static struct attribute *default_attrs[] = {
 #ifndef topology_die_no_sysfs
 	&dev_attr_die_id.attr,
 #endif
+#ifndef topology_cluster_no_sysfs
 	&dev_attr_cluster_id.attr,
+#endif
 	&dev_attr_core_id.attr,
 #ifdef CONFIG_SCHED_BOOK
 	&dev_attr_book_id.attr,
diff --git a/include/linux/topology.h b/include/linux/topology.h
index 1541d210be24..cf57413f7c28 100644
--- a/include/linux/topology.h
+++ b/include/linux/topology.h
@@ -189,6 +189,7 @@ static inline int cpu_to_mem(int cpu)
 #endif
 #ifndef topology_cluster_id
 #define topology_cluster_id(cpu)		((void)(cpu), -1)
+#define topology_cluster_no_sysfs		1
 #endif
 #ifndef topology_core_id
 #define topology_core_id(cpu)			((void)(cpu), 0)
@@ -201,6 +202,7 @@ static inline int cpu_to_mem(int cpu)
 #endif
 #ifndef topology_cluster_cpumask
 #define topology_cluster_cpumask(cpu)		cpumask_of(cpu)
+#define topology_cluster_no_sysfs		1
 #endif
 #ifndef topology_die_cpumask
 #define topology_die_cpumask(cpu)		cpumask_of(cpu)
-- 
2.32.0

Re: [PATCH 2/3] topology/sysfs: export cluster attributes only if an architectures has support

[Greg Kroah-Hartman]

On Sun, Nov 28, 2021 at 10:22:20PM +0100, Heiko Carstens wrote:
> The cluster_id and cluster_cpus topology sysfs attributes have been
> added with c5e22feffdd7 ("topology: Represent clusters of CPUs within
> a die").
> 
> They are currently only used for x86, arm64, and riscv (via generic
> arch topology), however they are still present with bogus default
> values for all other architectures. Instead of enforcing such new
> sysfs attributes to all architectures, make them only optional visible
> if an architecture opts in by defining both the topology_cluster_id
> and topology_cluster_cpumask attributes.
> 
> This is similar to what was done when the book and drawer topology
> levels were introduced: avoid useless and therefore confusing sysfs
> attributes for architectures which cannot make use of them.
> 
> This should not break any existing applications, since this is a
> new interface introduced with the v5.16 merge window.
> 
> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
> ---
>  Documentation/admin-guide/cputopology.rst | 4 ++--
>  drivers/base/topology.c                   | 8 ++++++++
>  include/linux/topology.h                  | 2 ++
>  3 files changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/admin-guide/cputopology.rst b/Documentation/admin-guide/cputopology.rst
> index c68d07533c45..ad2238b41439 100644
> --- a/Documentation/admin-guide/cputopology.rst
> +++ b/Documentation/admin-guide/cputopology.rst
> @@ -11,8 +11,8 @@ Architecture-neutral, drivers/base/topology.c, exports these attributes.
>  However, the book and drawer related sysfs files will only be created if
>  CONFIG_SCHED_BOOK and CONFIG_SCHED_DRAWER are selected, respectively.
>  
> -The die hierarchy related sysfs files will only be created if an architecture
> -provides the related macros as described below.
> +The die and cluster hierarchy related sysfs files will only be created if an
> +architecture provides the related macros as described below.
>  
>  CONFIG_SCHED_BOOK and CONFIG_SCHED_DRAWER are currently only used on s390,
>  where they reflect the cpu and cache hierarchy.
> diff --git a/drivers/base/topology.c b/drivers/base/topology.c
> index 7fa5a7fbef25..1a288eac2c44 100644
> --- a/drivers/base/topology.c
> +++ b/drivers/base/topology.c
> @@ -50,8 +50,10 @@ define_id_show_func(die_id);
>  static DEVICE_ATTR_RO(die_id);
>  #endif
>  
> +#ifndef topology_cluster_no_sysfs

Same comment here, do not enable an option that disables something :)

thanks,

greg k-h

[PATCH 3/3] topology/sysfs: rework book and drawer topology ifdefery

[Heiko Carstens]

Provide default defines for the topology_book_[id|cpumask] and
topology_drawer_[id|cpumask] macros just like for each other topology
level.
This way all topology levels are handled in a similar way. Still the
the book and drawer levels are only used on s390, and also the sysfs
attributes are only created on s390. However other architectures may
opt in if wanted.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
---
 Documentation/admin-guide/cputopology.rst | 36 ++++++++++-------------
 drivers/base/topology.c                   | 12 ++++----
 include/linux/topology.h                  | 16 ++++++++++
 3 files changed, 37 insertions(+), 27 deletions(-)

diff --git a/Documentation/admin-guide/cputopology.rst b/Documentation/admin-guide/cputopology.rst
index ad2238b41439..677ba1c2c820 100644
--- a/Documentation/admin-guide/cputopology.rst
+++ b/Documentation/admin-guide/cputopology.rst
@@ -8,14 +8,9 @@ to /proc/cpuinfo output of some architectures. They reside in
 Documentation/ABI/stable/sysfs-devices-system-cpu.
 
 Architecture-neutral, drivers/base/topology.c, exports these attributes.
-However, the book and drawer related sysfs files will only be created if
-CONFIG_SCHED_BOOK and CONFIG_SCHED_DRAWER are selected, respectively.
-
-The die and cluster hierarchy related sysfs files will only be created if an
-architecture provides the related macros as described below.
-
-CONFIG_SCHED_BOOK and CONFIG_SCHED_DRAWER are currently only used on s390,
-where they reflect the cpu and cache hierarchy.
+However the die, cluster, book, and drawer hierarchy related sysfs files will
+only be created if an architecture provides the related macros as described
+below.
 
 For an architecture to support this feature, it must define some of
 these macros in include/asm-XXX/topology.h::
@@ -42,19 +37,18 @@ 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) topology_physical_package_id: -1
-2) topology_die_id: -1
-3) topology_cluster_id: -1
-4) topology_core_id: 0
-5) topology_sibling_cpumask: just the given CPU
-6) topology_core_cpumask: just the given CPU
-7) topology_cluster_cpumask: just the given CPU
-8) topology_die_cpumask: 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().
-For architectures that don't support drawers (CONFIG_SCHED_DRAWER) there are
-no default definitions for topology_drawer_id() and topology_drawer_cpumask().
+ 1) topology_physical_package_id: -1
+ 2) topology_die_id: -1
+ 3) topology_cluster_id: -1
+ 4) topology_core_id: 0
+ 5) topology_book_id: -1
+ 6) topology_drawer_id: -1
+ 7) topology_sibling_cpumask: just the given CPU
+ 8) topology_core_cpumask: just the given CPU
+ 9) topology_cluster_cpumask: just the given CPU
+10) topology_die_cpumask: just the given CPU
+11) topology_book_cpumask:  just the given CPU
+12) topology_drawer_cpumask: just the given CPU
 
 Additionally, CPU topology information is provided under
 /sys/devices/system/cpu and includes these files.  The internal
diff --git a/drivers/base/topology.c b/drivers/base/topology.c
index 1a288eac2c44..a942fadd3c5b 100644
--- a/drivers/base/topology.c
+++ b/drivers/base/topology.c
@@ -86,7 +86,7 @@ define_siblings_read_func(package_cpus, core_cpumask);
 static BIN_ATTR_RO(package_cpus, 0);
 static BIN_ATTR_RO(package_cpus_list, 0);
 
-#ifdef CONFIG_SCHED_BOOK
+#ifndef topology_book_no_sysfs
 define_id_show_func(book_id);
 static DEVICE_ATTR_RO(book_id);
 define_siblings_read_func(book_siblings, book_cpumask);
@@ -94,7 +94,7 @@ static BIN_ATTR_RO(book_siblings, 0);
 static BIN_ATTR_RO(book_siblings_list, 0);
 #endif
 
-#ifdef CONFIG_SCHED_DRAWER
+#ifndef topology_drawer_no_sysfs
 define_id_show_func(drawer_id);
 static DEVICE_ATTR_RO(drawer_id);
 define_siblings_read_func(drawer_siblings, drawer_cpumask);
@@ -119,11 +119,11 @@ static struct bin_attribute *bin_attrs[] = {
 #endif
 	&bin_attr_package_cpus,
 	&bin_attr_package_cpus_list,
-#ifdef CONFIG_SCHED_BOOK
+#ifndef topology_book_no_sysfs
 	&bin_attr_book_siblings,
 	&bin_attr_book_siblings_list,
 #endif
-#ifdef CONFIG_SCHED_DRAWER
+#ifndef topology_drawer_no_sysfs
 	&bin_attr_drawer_siblings,
 	&bin_attr_drawer_siblings_list,
 #endif
@@ -139,10 +139,10 @@ static struct attribute *default_attrs[] = {
 	&dev_attr_cluster_id.attr,
 #endif
 	&dev_attr_core_id.attr,
-#ifdef CONFIG_SCHED_BOOK
+#ifndef topology_book_no_sysfs
 	&dev_attr_book_id.attr,
 #endif
-#ifdef CONFIG_SCHED_DRAWER
+#ifndef topology_drawer_no_sysfs
 	&dev_attr_drawer_id.attr,
 #endif
 	NULL
diff --git a/include/linux/topology.h b/include/linux/topology.h
index cf57413f7c28..20c1a41c1670 100644
--- a/include/linux/topology.h
+++ b/include/linux/topology.h
@@ -194,6 +194,14 @@ static inline int cpu_to_mem(int cpu)
 #ifndef topology_core_id
 #define topology_core_id(cpu)			((void)(cpu), 0)
 #endif
+#ifndef topology_book_id
+#define topology_book_id(cpu)			((void)(cpu), -1)
+#define topology_book_no_sysfs			1
+#endif
+#ifndef topology_drawer_id
+#define topology_drawer_id(cpu)			((void)(cpu), -1)
+#define topology_drawer_no_sysfs		1
+#endif
 #ifndef topology_sibling_cpumask
 #define topology_sibling_cpumask(cpu)		cpumask_of(cpu)
 #endif
@@ -208,6 +216,14 @@ static inline int cpu_to_mem(int cpu)
 #define topology_die_cpumask(cpu)		cpumask_of(cpu)
 #define topology_die_no_sysfs			1
 #endif
+#ifndef topology_book_cpumask
+#define topology_book_cpumask(cpu)		cpumask_of(cpu)
+#define topology_book_no_sysfs			1
+#endif
+#ifndef topology_drawer_cpumask
+#define topology_drawer_cpumask(cpu)		cpumask_of(cpu)
+#define topology_drawer_no_sysfs		1
+#endif
 
 #if defined(CONFIG_SCHED_SMT) && !defined(cpu_smt_mask)
 static inline const struct cpumask *cpu_smt_mask(int cpu)
-- 
2.32.0

Re: [PATCH 3/3] topology/sysfs: rework book and drawer topology ifdefery

[Greg Kroah-Hartman]

On Sun, Nov 28, 2021 at 10:22:21PM +0100, Heiko Carstens wrote:
> Provide default defines for the topology_book_[id|cpumask] and
> topology_drawer_[id|cpumask] macros just like for each other topology
> level.
> This way all topology levels are handled in a similar way. Still the
> the book and drawer levels are only used on s390, and also the sysfs
> attributes are only created on s390. However other architectures may
> opt in if wanted.
> 
> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
> ---
>  Documentation/admin-guide/cputopology.rst | 36 ++++++++++-------------
>  drivers/base/topology.c                   | 12 ++++----
>  include/linux/topology.h                  | 16 ++++++++++
>  3 files changed, 37 insertions(+), 27 deletions(-)
> 
> diff --git a/Documentation/admin-guide/cputopology.rst b/Documentation/admin-guide/cputopology.rst
> index ad2238b41439..677ba1c2c820 100644
> --- a/Documentation/admin-guide/cputopology.rst
> +++ b/Documentation/admin-guide/cputopology.rst
> @@ -8,14 +8,9 @@ to /proc/cpuinfo output of some architectures. They reside in
>  Documentation/ABI/stable/sysfs-devices-system-cpu.
>  
>  Architecture-neutral, drivers/base/topology.c, exports these attributes.
> -However, the book and drawer related sysfs files will only be created if
> -CONFIG_SCHED_BOOK and CONFIG_SCHED_DRAWER are selected, respectively.
> -
> -The die and cluster hierarchy related sysfs files will only be created if an
> -architecture provides the related macros as described below.
> -
> -CONFIG_SCHED_BOOK and CONFIG_SCHED_DRAWER are currently only used on s390,
> -where they reflect the cpu and cache hierarchy.
> +However the die, cluster, book, and drawer hierarchy related sysfs files will
> +only be created if an architecture provides the related macros as described
> +below.
>  
>  For an architecture to support this feature, it must define some of
>  these macros in include/asm-XXX/topology.h::
> @@ -42,19 +37,18 @@ 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) topology_physical_package_id: -1
> -2) topology_die_id: -1
> -3) topology_cluster_id: -1
> -4) topology_core_id: 0
> -5) topology_sibling_cpumask: just the given CPU
> -6) topology_core_cpumask: just the given CPU
> -7) topology_cluster_cpumask: just the given CPU
> -8) topology_die_cpumask: 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().
> -For architectures that don't support drawers (CONFIG_SCHED_DRAWER) there are
> -no default definitions for topology_drawer_id() and topology_drawer_cpumask().
> + 1) topology_physical_package_id: -1
> + 2) topology_die_id: -1
> + 3) topology_cluster_id: -1
> + 4) topology_core_id: 0
> + 5) topology_book_id: -1
> + 6) topology_drawer_id: -1
> + 7) topology_sibling_cpumask: just the given CPU
> + 8) topology_core_cpumask: just the given CPU
> + 9) topology_cluster_cpumask: just the given CPU
> +10) topology_die_cpumask: just the given CPU
> +11) topology_book_cpumask:  just the given CPU
> +12) topology_drawer_cpumask: just the given CPU
>  
>  Additionally, CPU topology information is provided under
>  /sys/devices/system/cpu and includes these files.  The internal
> diff --git a/drivers/base/topology.c b/drivers/base/topology.c
> index 1a288eac2c44..a942fadd3c5b 100644
> --- a/drivers/base/topology.c
> +++ b/drivers/base/topology.c
> @@ -86,7 +86,7 @@ define_siblings_read_func(package_cpus, core_cpumask);
>  static BIN_ATTR_RO(package_cpus, 0);
>  static BIN_ATTR_RO(package_cpus_list, 0);
>  
> -#ifdef CONFIG_SCHED_BOOK
> +#ifndef topology_book_no_sysfs
>  define_id_show_func(book_id);
>  static DEVICE_ATTR_RO(book_id);
>  define_siblings_read_func(book_siblings, book_cpumask);
> @@ -94,7 +94,7 @@ static BIN_ATTR_RO(book_siblings, 0);
>  static BIN_ATTR_RO(book_siblings_list, 0);
>  #endif
>  
> -#ifdef CONFIG_SCHED_DRAWER
> +#ifndef topology_drawer_no_sysfs
>  define_id_show_func(drawer_id);
>  static DEVICE_ATTR_RO(drawer_id);
>  define_siblings_read_func(drawer_siblings, drawer_cpumask);
> @@ -119,11 +119,11 @@ static struct bin_attribute *bin_attrs[] = {
>  #endif
>  	&bin_attr_package_cpus,
>  	&bin_attr_package_cpus_list,
> -#ifdef CONFIG_SCHED_BOOK
> +#ifndef topology_book_no_sysfs

Again, flip around:
	TOPOLOGY_BOOK_SYSFS

thanks,

greg k-h