The patch titled
Subject: mm: remove CONFIG_DISCONTIGMEM
has been added to the -mm tree. Its filename is
mm-remove-config_discontigmem.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-remove-config_discontigmem.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-remove-config_discontigmem.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Subject: mm: remove CONFIG_DISCONTIGMEM
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.
Link: https://lkml.kernel.org/r/20210608091316.3622-6-rppt@xxxxxxxxxx
Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Cc: Ivan Kokshaysky <ink@xxxxxxxxxxxxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Matt Turner <mattst88@xxxxxxxxx>
Cc: Richard Henderson <rth@xxxxxxxxxxx>
Cc: Vineet Gupta <vgupta@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
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(-)
--- a/include/asm-generic/memory_model.h~mm-remove-config_discontigmem
+++ a/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
--- a/include/linux/mmzone.h~mm-remove-config_discontigmem
+++ a/include/linux/mmzone.h
@@ -767,10 +767,12 @@ 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 {
--- a/mm/Kconfig~mm-remove-config_discontigmem
+++ a/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
def_bool y
- depends on DISCONTIGMEM || NUMA
+ depends on NUMA
#
# SPARSEMEM_EXTREME (which is the default) does some bootmem
--- a/mm/page_alloc.c~mm-remove-config_discontigmem
+++ a/mm/page_alloc.c
@@ -349,20 +349,7 @@ compound_page_dtor * const compound_page
int min_free_kbytes = 1024;
int user_min_free_kbytes = -1;
-#ifdef CONFIG_DISCONTIGMEM
-/*
- * DiscontigMem defines memory ranges as separate pg_data_t even if the ranges
- * are not on separate NUMA nodes. Functionally this works but with
- * watermark_boost_factor, it can reclaim prematurely as the ranges can be
- * quite small. By default, do not boost watermarks on discontigmem as in
- * many cases very high-order allocations like THP are likely to be
- * unsupported and the premature reclaim offsets the advantage of long-term
- * fragmentation avoidance.
- */
-int watermark_boost_factor __read_mostly;
-#else
int watermark_boost_factor __read_mostly = 15000;
-#endif
int watermark_scale_factor = 10;
static unsigned long nr_kernel_pages __initdata;
_
Patches currently in -mm which might be from rppt@xxxxxxxxxxxxx are
mm-mmzoneh-simplify-is_highmem_idx.patch
alpha-remove-discontigmem-and-numa.patch
arc-update-comment-about-highmem-implementation.patch
arc-remove-support-for-discontigmem.patch
m68k-remove-support-for-discontigmem.patch
mm-remove-config_discontigmem.patch
arch-mm-remove-stale-mentions-of-disconigmem.patch
docs-remove-description-of-discontigmem.patch
mm-replace-config_need_multiple_nodes-with-config_numa.patch
mm-replace-config_flat_node_mem_map-with-config_flatmem.patch
docs-procrst-meminfo-briefly-describe-gaps-in-memory-accounting.patch
include-linux-mmzoneh-add-documentation-for-pfn_valid.patch
memblock-update-initialization-of-reserved-pages.patch
arm64-decouple-check-whether-pfn-is-in-linear-map-from-pfn_valid.patch
arm64-drop-pfn_valid_within-and-simplify-pfn_valid.patch
mmap-make-mlock_future_check-global.patch
riscv-kconfig-make-direct-map-manipulation-options-depend-on-mmu.patch
set_memory-allow-querying-whether-set_direct_map_-is-actually-enabled.patch
mm-introduce-memfd_secret-system-call-to-create-secret-memory-areas.patch
pm-hibernate-disable-when-there-are-active-secretmem-users.patch
arch-mm-wire-up-memfd_secret-system-call-where-relevant.patch
secretmem-test-add-basic-selftest-for-memfd_secret2.patch
