Re: [PATCH v3 5/9] mm: remove CONFIG_DISCONTIGMEM
On Fri, Jun 11, 2021 at 01:53:48PM -0700, Stephen Brennan wrote:
> Mike Rapoport writes:
> > From: Mike Rapoport
> >
> > There are no architectures that support DISCONTIGMEM left.
> >
> > Remove the configuration option and the dead code it was guarding in the
> > generic memory management code.
> >
> > Signed-off-by: Mike Rapoport
> > ---
> > include/asm-generic/memory_model.h | 37 --
> > include/linux/mmzone.h | 8 ---
> > mm/Kconfig | 25 +++-
> > mm/page_alloc.c| 13 ---
> > 4 files changed, 12 insertions(+), 71 deletions(-)
> >
> > diff --git a/include/asm-generic/memory_model.h
> > b/include/asm-generic/memory_model.h
> > index 7637fb46ba4f..a2c8ed60233a 100644
> > --- a/include/asm-generic/memory_model.h
> > +++ b/include/asm-generic/memory_model.h
> > @@ -6,47 +6,18 @@
> >
> > #ifndef __ASSEMBLY__
> >
> > +/*
> > + * supports 3 memory models.
> > + */
>
> This comment could either be updated to reflect 2 memory models, or
> removed entirely.
I counted SPARSE and SPARSE_VMEMMAP as 2.
The code below has three clauses: one for FLATMEM, one for SPARSE and one
for VMEMMAP.
> Thanks,
> Stephen
>
> > #if defined(CONFIG_FLATMEM)
> >
> > #ifndef ARCH_PFN_OFFSET
> > #define ARCH_PFN_OFFSET(0UL)
> > #endif
> >
> > -#elif defined(CONFIG_DISCONTIGMEM)
> > -
> > -#ifndef arch_pfn_to_nid
> > -#define arch_pfn_to_nid(pfn) pfn_to_nid(pfn)
> > -#endif
> > -
> > -#ifndef arch_local_page_offset
> > -#define arch_local_page_offset(pfn, nid) \
> > - ((pfn) - NODE_DATA(nid)->node_start_pfn)
> > -#endif
> > -
> > -#endif /* CONFIG_DISCONTIGMEM */
> > -
> > -/*
> > - * supports 3 memory models.
> > - */
> > -#if defined(CONFIG_FLATMEM)
> > -
> > #define __pfn_to_page(pfn) (mem_map + ((pfn) - ARCH_PFN_OFFSET))
> > #define __page_to_pfn(page)((unsigned long)((page) - mem_map) + \
> > ARCH_PFN_OFFSET)
> > -#elif defined(CONFIG_DISCONTIGMEM)
> > -
> > -#define __pfn_to_page(pfn) \
> > -({ unsigned long __pfn = (pfn);\
> > - unsigned long __nid = arch_pfn_to_nid(__pfn); \
> > - NODE_DATA(__nid)->node_mem_map + arch_local_page_offset(__pfn, __nid);\
> > -})
> > -
> > -#define __page_to_pfn(pg) \
> > -({ const struct page *__pg = (pg); \
> > - struct pglist_data *__pgdat = NODE_DATA(page_to_nid(__pg)); \
> > - (unsigned long)(__pg - __pgdat->node_mem_map) + \
> > -__pgdat->node_start_pfn; \
> > -})
> >
> > #elif defined(CONFIG_SPARSEMEM_VMEMMAP)
> >
> > @@ -70,7 +41,7 @@
> > struct mem_section *__sec = __pfn_to_section(__pfn);\
> > __section_mem_map_addr(__sec) + __pfn; \
> > })
> > -#endif /* CONFIG_FLATMEM/DISCONTIGMEM/SPARSEMEM */
> > +#endif /* CONFIG_FLATMEM/SPARSEMEM */
> >
> > /*
> > * Convert a physical address to a Page Frame Number and back
> > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
> > index 0d53eba1c383..700032e99419 100644
> > --- a/include/linux/mmzone.h
> > +++ b/include/linux/mmzone.h
> > @@ -738,10 +738,12 @@ struct zonelist {
> > struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1];
> > };
> >
> > -#ifndef CONFIG_DISCONTIGMEM
> > -/* The array of struct pages - for discontigmem use pgdat->lmem_map */
> > +/*
> > + * The array of struct pages for flatmem.
> > + * It must be declared for SPARSEMEM as well because there are
> > configurations
> > + * that rely on that.
> > + */
> > extern struct page *mem_map;
> > -#endif
> >
> > #ifdef CONFIG_TRANSPARENT_HUGEPAGE
> > struct deferred_split {
> > diff --git a/mm/Kconfig b/mm/Kconfig
> > index 02d44e3420f5..218b96ccc84a 100644
> > --- a/mm/Kconfig
> > +++ b/mm/Kconfig
> > @@ -19,7 +19,7 @@ choice
> >
> > config FLATMEM_MANUAL
> > bool "Flat Memory"
> > - depends on !(ARCH_DISCONTIGMEM_ENABLE || ARCH_SPARSEMEM_ENABLE) ||
> > ARCH_FLATMEM_ENABLE
> > + depends on !ARCH_SPARSEMEM_ENABLE || ARCH_FLATMEM_ENABLE
> > help
> > This option is best suited for non-NUMA systems with
> > flat address space. The FLATMEM is the most efficient
> > @@ -32,21 +32,6 @@ config FLATMEM_MANUAL
> >
> > If unsure, choose this option (Flat Memory) over any other.
> >
> > -config DISCONTIGMEM_MANUAL
> > - bool "Discontiguous Memory"
> > - depends on ARCH_DISCONTIGMEM_ENABLE
> > - help
> > - This option provides enhanced support for discontiguous
> > - memory systems, over FLATMEM. These systems have holes
> > - in their physical address spaces, and this option provides
> > - more efficient handling of these holes.
> > -
> > - Although "Discontiguous Memory" is still used by several
> > - architectures, it is considered deprecated in favor of
> > - "Sparse Memory".
> > -
> > - If unsure,
Re: [PATCH v3 5/9] mm: remove CONFIG_DISCONTIGMEM
Mike Rapoport writes:
> From: Mike Rapoport
>
> There are no architectures that support DISCONTIGMEM left.
>
> Remove the configuration option and the dead code it was guarding in the
> generic memory management code.
>
> Signed-off-by: Mike Rapoport
> ---
> include/asm-generic/memory_model.h | 37 --
> include/linux/mmzone.h | 8 ---
> mm/Kconfig | 25 +++-
> mm/page_alloc.c| 13 ---
> 4 files changed, 12 insertions(+), 71 deletions(-)
>
> diff --git a/include/asm-generic/memory_model.h
> b/include/asm-generic/memory_model.h
> index 7637fb46ba4f..a2c8ed60233a 100644
> --- a/include/asm-generic/memory_model.h
> +++ b/include/asm-generic/memory_model.h
> @@ -6,47 +6,18 @@
>
> #ifndef __ASSEMBLY__
>
> +/*
> + * supports 3 memory models.
> + */
This comment could either be updated to reflect 2 memory models, or
removed entirely.
Thanks,
Stephen
> #if defined(CONFIG_FLATMEM)
>
> #ifndef ARCH_PFN_OFFSET
> #define ARCH_PFN_OFFSET (0UL)
> #endif
>
> -#elif defined(CONFIG_DISCONTIGMEM)
> -
> -#ifndef arch_pfn_to_nid
> -#define arch_pfn_to_nid(pfn) pfn_to_nid(pfn)
> -#endif
> -
> -#ifndef arch_local_page_offset
> -#define arch_local_page_offset(pfn, nid) \
> - ((pfn) - NODE_DATA(nid)->node_start_pfn)
> -#endif
> -
> -#endif /* CONFIG_DISCONTIGMEM */
> -
> -/*
> - * supports 3 memory models.
> - */
> -#if defined(CONFIG_FLATMEM)
> -
> #define __pfn_to_page(pfn) (mem_map + ((pfn) - ARCH_PFN_OFFSET))
> #define __page_to_pfn(page) ((unsigned long)((page) - mem_map) + \
>ARCH_PFN_OFFSET)
> -#elif defined(CONFIG_DISCONTIGMEM)
> -
> -#define __pfn_to_page(pfn) \
> -({ unsigned long __pfn = (pfn);\
> - unsigned long __nid = arch_pfn_to_nid(__pfn); \
> - NODE_DATA(__nid)->node_mem_map + arch_local_page_offset(__pfn, __nid);\
> -})
> -
> -#define __page_to_pfn(pg)\
> -({ const struct page *__pg = (pg); \
> - struct pglist_data *__pgdat = NODE_DATA(page_to_nid(__pg)); \
> - (unsigned long)(__pg - __pgdat->node_mem_map) + \
> - __pgdat->node_start_pfn; \
> -})
>
> #elif defined(CONFIG_SPARSEMEM_VMEMMAP)
>
> @@ -70,7 +41,7 @@
> struct mem_section *__sec = __pfn_to_section(__pfn);\
> __section_mem_map_addr(__sec) + __pfn; \
> })
> -#endif /* CONFIG_FLATMEM/DISCONTIGMEM/SPARSEMEM */
> +#endif /* CONFIG_FLATMEM/SPARSEMEM */
>
> /*
> * Convert a physical address to a Page Frame Number and back
> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
> index 0d53eba1c383..700032e99419 100644
> --- a/include/linux/mmzone.h
> +++ b/include/linux/mmzone.h
> @@ -738,10 +738,12 @@ struct zonelist {
> struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1];
> };
>
> -#ifndef CONFIG_DISCONTIGMEM
> -/* The array of struct pages - for discontigmem use pgdat->lmem_map */
> +/*
> + * The array of struct pages for flatmem.
> + * It must be declared for SPARSEMEM as well because there are configurations
> + * that rely on that.
> + */
> extern struct page *mem_map;
> -#endif
>
> #ifdef CONFIG_TRANSPARENT_HUGEPAGE
> struct deferred_split {
> diff --git a/mm/Kconfig b/mm/Kconfig
> index 02d44e3420f5..218b96ccc84a 100644
> --- a/mm/Kconfig
> +++ b/mm/Kconfig
> @@ -19,7 +19,7 @@ choice
>
> config FLATMEM_MANUAL
> bool "Flat Memory"
> - depends on !(ARCH_DISCONTIGMEM_ENABLE || ARCH_SPARSEMEM_ENABLE) ||
> ARCH_FLATMEM_ENABLE
> + depends on !ARCH_SPARSEMEM_ENABLE || ARCH_FLATMEM_ENABLE
> help
> This option is best suited for non-NUMA systems with
> flat address space. The FLATMEM is the most efficient
> @@ -32,21 +32,6 @@ config FLATMEM_MANUAL
>
> If unsure, choose this option (Flat Memory) over any other.
>
> -config DISCONTIGMEM_MANUAL
> - bool "Discontiguous Memory"
> - depends on ARCH_DISCONTIGMEM_ENABLE
> - help
> - This option provides enhanced support for discontiguous
> - memory systems, over FLATMEM. These systems have holes
> - in their physical address spaces, and this option provides
> - more efficient handling of these holes.
> -
> - Although "Discontiguous Memory" is still used by several
> - architectures, it is considered deprecated in favor of
> - "Sparse Memory".
> -
> - If unsure, choose "Sparse Memory" over this option.
> -
> config SPARSEMEM_MANUAL
> bool "Sparse Memory"
> depends on ARCH_SPARSEMEM_ENABLE
> @@ -62,17 +47,13 @@ config SPARSEMEM_MANUAL
>
> endchoice
>
> -config DISCONTIGMEM
> - def_bool y
> - depends on (!SELECT_MEMORY_MODEL && ARCH_DISCONTIGMEM_ENABLE) ||
> DISCONTIGMEM_MANUAL
> -
> config SPARSEMEM
> def_bool y
> depends on
[PATCH v3 5/9] mm: remove CONFIG_DISCONTIGMEM
From: Mike Rapoport
There are no architectures that support DISCONTIGMEM left.
Remove the configuration option and the dead code it was guarding in the
generic memory management code.
Signed-off-by: Mike Rapoport
---
include/asm-generic/memory_model.h | 37 --
include/linux/mmzone.h | 8 ---
mm/Kconfig | 25 +++-
mm/page_alloc.c| 13 ---
4 files changed, 12 insertions(+), 71 deletions(-)
diff --git a/include/asm-generic/memory_model.h
b/include/asm-generic/memory_model.h
index 7637fb46ba4f..a2c8ed60233a 100644
--- a/include/asm-generic/memory_model.h
+++ b/include/asm-generic/memory_model.h
@@ -6,47 +6,18 @@
#ifndef __ASSEMBLY__
+/*
+ * supports 3 memory models.
+ */
#if defined(CONFIG_FLATMEM)
#ifndef ARCH_PFN_OFFSET
#define ARCH_PFN_OFFSET(0UL)
#endif
-#elif defined(CONFIG_DISCONTIGMEM)
-
-#ifndef arch_pfn_to_nid
-#define arch_pfn_to_nid(pfn) pfn_to_nid(pfn)
-#endif
-
-#ifndef arch_local_page_offset
-#define arch_local_page_offset(pfn, nid) \
- ((pfn) - NODE_DATA(nid)->node_start_pfn)
-#endif
-
-#endif /* CONFIG_DISCONTIGMEM */
-
-/*
- * supports 3 memory models.
- */
-#if defined(CONFIG_FLATMEM)
-
#define __pfn_to_page(pfn) (mem_map + ((pfn) - ARCH_PFN_OFFSET))
#define __page_to_pfn(page)((unsigned long)((page) - mem_map) + \
ARCH_PFN_OFFSET)
-#elif defined(CONFIG_DISCONTIGMEM)
-
-#define __pfn_to_page(pfn) \
-({ unsigned long __pfn = (pfn);\
- unsigned long __nid = arch_pfn_to_nid(__pfn); \
- NODE_DATA(__nid)->node_mem_map + arch_local_page_offset(__pfn, __nid);\
-})
-
-#define __page_to_pfn(pg) \
-({ const struct page *__pg = (pg); \
- struct pglist_data *__pgdat = NODE_DATA(page_to_nid(__pg)); \
- (unsigned long)(__pg - __pgdat->node_mem_map) + \
-__pgdat->node_start_pfn; \
-})
#elif defined(CONFIG_SPARSEMEM_VMEMMAP)
@@ -70,7 +41,7 @@
struct mem_section *__sec = __pfn_to_section(__pfn);\
__section_mem_map_addr(__sec) + __pfn; \
})
-#endif /* CONFIG_FLATMEM/DISCONTIGMEM/SPARSEMEM */
+#endif /* CONFIG_FLATMEM/SPARSEMEM */
/*
* Convert a physical address to a Page Frame Number and back
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 0d53eba1c383..700032e99419 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -738,10 +738,12 @@ struct zonelist {
struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1];
};
-#ifndef CONFIG_DISCONTIGMEM
-/* The array of struct pages - for discontigmem use pgdat->lmem_map */
+/*
+ * The array of struct pages for flatmem.
+ * It must be declared for SPARSEMEM as well because there are configurations
+ * that rely on that.
+ */
extern struct page *mem_map;
-#endif
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
struct deferred_split {
diff --git a/mm/Kconfig b/mm/Kconfig
index 02d44e3420f5..218b96ccc84a 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -19,7 +19,7 @@ choice
config FLATMEM_MANUAL
bool "Flat Memory"
- depends on !(ARCH_DISCONTIGMEM_ENABLE || ARCH_SPARSEMEM_ENABLE) ||
ARCH_FLATMEM_ENABLE
+ depends on !ARCH_SPARSEMEM_ENABLE || ARCH_FLATMEM_ENABLE
help
This option is best suited for non-NUMA systems with
flat address space. The FLATMEM is the most efficient
@@ -32,21 +32,6 @@ config FLATMEM_MANUAL
If unsure, choose this option (Flat Memory) over any other.
-config DISCONTIGMEM_MANUAL
- bool "Discontiguous Memory"
- depends on ARCH_DISCONTIGMEM_ENABLE
- help
- This option provides enhanced support for discontiguous
- memory systems, over FLATMEM. These systems have holes
- in their physical address spaces, and this option provides
- more efficient handling of these holes.
-
- Although "Discontiguous Memory" is still used by several
- architectures, it is considered deprecated in favor of
- "Sparse Memory".
-
- If unsure, choose "Sparse Memory" over this option.
-
config SPARSEMEM_MANUAL
bool "Sparse Memory"
depends on ARCH_SPARSEMEM_ENABLE
@@ -62,17 +47,13 @@ config SPARSEMEM_MANUAL
endchoice
-config DISCONTIGMEM
- def_bool y
- depends on (!SELECT_MEMORY_MODEL && ARCH_DISCONTIGMEM_ENABLE) ||
DISCONTIGMEM_MANUAL
-
config SPARSEMEM
def_bool y
depends on (!SELECT_MEMORY_MODEL && ARCH_SPARSEMEM_ENABLE) ||
SPARSEMEM_MANUAL
config FLATMEM
def_bool y
- depends on (!DISCONTIGMEM && !SPARSEMEM) || FLATMEM_MANUAL
+ depends on !SPARSEMEM || FLATMEM_MANUAL
config FLAT_NODE_MEM_MAP
def_bool y
@@ -85,7 +66,7 @@ config FLAT_NODE_MEM_MAP
#
config NEED_MULTIPLE_NODES
