[PATCH v2 0/9] Remove DISCINTIGMEM memory model

[PATCH v2 0/9] Remove DISCINTIGMEM memory model

[Mike Rapoport]

From: Mike Rapoport <rppt@linux.ibm.com>

Hi,

SPARSEMEM memory model was supposed to entirely replace DISCONTIGMEM a
(long) while ago. The last architectures that used DISCONTIGMEM were
updated to use other memory models in v5.11 and it is about the time to
entirely remove DISCONTIGMEM from the kernel.

This set removes DISCONTIGMEM from alpha, arc and m68k, simplifies memory
model selection in mm/Kconfig and replaces usage of redundant
CONFIG_NEED_MULTIPLE_NODES and CONFIG_FLAT_NODE_MEM_MAP with CONFIG_NUMA
and CONFIG_FLATMEM respectively. 

I've also removed NUMA support on alpha that was BROKEN for more than 15
years.

There were also minor updates all over arch/ to remove mentions of
DISCONTIGMEM in comments and #ifdefs.

v2:
* Fix build errors reported by kbuild bot
* Add additional cleanups in m68k as suggested by Geert

v1: Link: https://lore.kernel.org/lkml/20210602105348.13387-1-rppt@kernel.org

Mike Rapoport (9):
  alpha: remove DISCONTIGMEM and NUMA
  arc: update comment about HIGHMEM implementation
  arc: remove support for DISCONTIGMEM
  m68k: remove support for DISCONTIGMEM
  mm: remove CONFIG_DISCONTIGMEM
  arch, mm: remove stale mentions of DISCONIGMEM
  docs: remove description of DISCONTIGMEM
  mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA
  mm: replace CONFIG_FLAT_NODE_MEM_MAP with CONFIG_FLATMEM

 Documentation/admin-guide/sysctl/vm.rst |  12 +-
 Documentation/vm/memory-model.rst       |  45 +----
 arch/alpha/Kconfig                      |  22 ---
 arch/alpha/include/asm/machvec.h        |   6 -
 arch/alpha/include/asm/mmzone.h         | 100 -----------
 arch/alpha/include/asm/pgtable.h        |   4 -
 arch/alpha/include/asm/topology.h       |  39 -----
 arch/alpha/kernel/core_marvel.c         |  53 +-----
 arch/alpha/kernel/core_wildfire.c       |  29 +--
 arch/alpha/kernel/pci_iommu.c           |  29 ---
 arch/alpha/kernel/proto.h               |   8 -
 arch/alpha/kernel/setup.c               |  16 --
 arch/alpha/kernel/sys_marvel.c          |   5 -
 arch/alpha/kernel/sys_wildfire.c        |   5 -
 arch/alpha/mm/Makefile                  |   2 -
 arch/alpha/mm/init.c                    |   3 -
 arch/alpha/mm/numa.c                    | 223 ------------------------
 arch/arc/Kconfig                        |  13 --
 arch/arc/include/asm/mmzone.h           |  40 -----
 arch/arc/mm/init.c                      |  21 +--
 arch/arm64/Kconfig                      |   2 +-
 arch/ia64/Kconfig                       |   2 +-
 arch/ia64/kernel/topology.c             |   5 +-
 arch/ia64/mm/numa.c                     |   5 +-
 arch/m68k/Kconfig.cpu                   |  10 --
 arch/m68k/include/asm/mmzone.h          |  10 --
 arch/m68k/include/asm/page.h            |   2 +-
 arch/m68k/include/asm/page_mm.h         |  35 ----
 arch/m68k/mm/init.c                     |  20 ---
 arch/mips/Kconfig                       |   2 +-
 arch/mips/include/asm/mmzone.h          |   8 +-
 arch/mips/include/asm/page.h            |   2 +-
 arch/mips/mm/init.c                     |   7 +-
 arch/nds32/include/asm/memory.h         |   6 -
 arch/powerpc/Kconfig                    |   2 +-
 arch/powerpc/include/asm/mmzone.h       |   4 +-
 arch/powerpc/kernel/setup_64.c          |   2 +-
 arch/powerpc/kernel/smp.c               |   2 +-
 arch/powerpc/kexec/core.c               |   4 +-
 arch/powerpc/mm/Makefile                |   2 +-
 arch/powerpc/mm/mem.c                   |   4 +-
 arch/riscv/Kconfig                      |   2 +-
 arch/s390/Kconfig                       |   2 +-
 arch/sh/include/asm/mmzone.h            |   4 +-
 arch/sh/kernel/topology.c               |   2 +-
 arch/sh/mm/Kconfig                      |   2 +-
 arch/sh/mm/init.c                       |   2 +-
 arch/sparc/Kconfig                      |   2 +-
 arch/sparc/include/asm/mmzone.h         |   4 +-
 arch/sparc/kernel/smp_64.c              |   2 +-
 arch/sparc/mm/init_64.c                 |  12 +-
 arch/x86/Kconfig                        |   2 +-
 arch/x86/kernel/setup_percpu.c          |   6 +-
 arch/x86/mm/init_32.c                   |   4 +-
 arch/xtensa/include/asm/page.h          |   4 -
 include/asm-generic/memory_model.h      |  37 +---
 include/asm-generic/topology.h          |   2 +-
 include/linux/gfp.h                     |   4 +-
 include/linux/memblock.h                |   6 +-
 include/linux/mm.h                      |   4 +-
 include/linux/mmzone.h                  |  20 ++-
 kernel/crash_core.c                     |   4 +-
 mm/Kconfig                              |  36 +---
 mm/memblock.c                           |   8 +-
 mm/page_alloc.c                         |  25 +--
 mm/page_ext.c                           |   2 +-
 66 files changed, 100 insertions(+), 909 deletions(-)
 delete mode 100644 arch/alpha/include/asm/mmzone.h
 delete mode 100644 arch/alpha/mm/numa.c
 delete mode 100644 arch/arc/include/asm/mmzone.h
 delete mode 100644 arch/m68k/include/asm/mmzone.h


base-commit: c4681547bcce777daf576925a966ffa824edd09d
-- 
2.28.0

[PATCH v2 1/9] alpha: remove DISCONTIGMEM and NUMA

[Mike Rapoport]

From: Mike Rapoport <rppt@linux.ibm.com>

NUMA is marked broken on alpha for more than 15 years and DISCONTIGMEM was
replaced with SPARSEMEM in v5.11.

Remove both NUMA and DISCONTIGMEM support from alpha.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
---
 arch/alpha/Kconfig                |  22 ---
 arch/alpha/include/asm/machvec.h  |   6 -
 arch/alpha/include/asm/mmzone.h   | 100 --------------
 arch/alpha/include/asm/pgtable.h  |   4 -
 arch/alpha/include/asm/topology.h |  39 ------
 arch/alpha/kernel/core_marvel.c   |  53 +------
 arch/alpha/kernel/core_wildfire.c |  29 +---
 arch/alpha/kernel/pci_iommu.c     |  29 ----
 arch/alpha/kernel/proto.h         |   8 --
 arch/alpha/kernel/setup.c         |  16 ---
 arch/alpha/kernel/sys_marvel.c    |   5 -
 arch/alpha/kernel/sys_wildfire.c  |   5 -
 arch/alpha/mm/Makefile            |   2 -
 arch/alpha/mm/init.c              |   3 -
 arch/alpha/mm/numa.c              | 223 ------------------------------
 15 files changed, 4 insertions(+), 540 deletions(-)
 delete mode 100644 arch/alpha/include/asm/mmzone.h
 delete mode 100644 arch/alpha/mm/numa.c

diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index 5998106faa60..8954216b9956 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -549,29 +549,12 @@ config NR_CPUS
 	  MARVEL support can handle a maximum of 32 CPUs, all the others
 	  with working support have a maximum of 4 CPUs.
 
-config ARCH_DISCONTIGMEM_ENABLE
-	bool "Discontiguous Memory Support"
-	depends on BROKEN
-	help
-	  Say Y to support efficient handling of discontiguous physical memory,
-	  for architectures which are either NUMA (Non-Uniform Memory Access)
-	  or have huge holes in the physical address space for other reasons.
-	  See <file:Documentation/vm/numa.rst> for more.
-
 config ARCH_SPARSEMEM_ENABLE
 	bool "Sparse Memory Support"
 	help
 	  Say Y to support efficient handling of discontiguous physical memory,
 	  for systems that have huge holes in the physical address space.
 
-config NUMA
-	bool "NUMA Support (EXPERIMENTAL)"
-	depends on DISCONTIGMEM && BROKEN
-	help
-	  Say Y to compile the kernel to support NUMA (Non-Uniform Memory
-	  Access).  This option is for configuring high-end multiprocessor
-	  server machines.  If in doubt, say N.
-
 config ALPHA_WTINT
 	bool "Use WTINT" if ALPHA_SRM || ALPHA_GENERIC
 	default y if ALPHA_QEMU
@@ -596,11 +579,6 @@ config ALPHA_WTINT
 
 	  If unsure, say N.
 
-config NODES_SHIFT
-	int
-	default "7"
-	depends on NEED_MULTIPLE_NODES
-
 # LARGE_VMALLOC is racy, if you *really* need it then fix it first
 config ALPHA_LARGE_VMALLOC
 	bool
diff --git a/arch/alpha/include/asm/machvec.h b/arch/alpha/include/asm/machvec.h
index a4e96e2bec74..e49fabce7b33 100644
--- a/arch/alpha/include/asm/machvec.h
+++ b/arch/alpha/include/asm/machvec.h
@@ -99,12 +99,6 @@ struct alpha_machine_vector
 
 	const char *vector_name;
 
-	/* NUMA information */
-	int (*pa_to_nid)(unsigned long);
-	int (*cpuid_to_nid)(int);
-	unsigned long (*node_mem_start)(int);
-	unsigned long (*node_mem_size)(int);
-
 	/* System specific parameters.  */
 	union {
 	    struct {
diff --git a/arch/alpha/include/asm/mmzone.h b/arch/alpha/include/asm/mmzone.h
deleted file mode 100644
index 86644604d977..000000000000
--- a/arch/alpha/include/asm/mmzone.h
+++ /dev/null
@@ -1,100 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * Written by Kanoj Sarcar (kanoj@sgi.com) Aug 99
- * Adapted for the alpha wildfire architecture Jan 2001.
- */
-#ifndef _ASM_MMZONE_H_
-#define _ASM_MMZONE_H_
-
-#ifdef CONFIG_DISCONTIGMEM
-
-#include <asm/smp.h>
-
-/*
- * Following are macros that are specific to this numa platform.
- */
-
-extern pg_data_t node_data[];
-
-#define alpha_pa_to_nid(pa)		\
-        (alpha_mv.pa_to_nid 		\
-	 ? alpha_mv.pa_to_nid(pa)	\
-	 : (0))
-#define node_mem_start(nid)		\
-        (alpha_mv.node_mem_start 	\
-	 ? alpha_mv.node_mem_start(nid) \
-	 : (0UL))
-#define node_mem_size(nid)		\
-        (alpha_mv.node_mem_size 	\
-	 ? alpha_mv.node_mem_size(nid) 	\
-	 : ((nid) ? (0UL) : (~0UL)))
-
-#define pa_to_nid(pa)		alpha_pa_to_nid(pa)
-#define NODE_DATA(nid)		(&node_data[(nid)])
-
-#define node_localnr(pfn, nid)	((pfn) - NODE_DATA(nid)->node_start_pfn)
-
-#if 1
-#define PLAT_NODE_DATA_LOCALNR(p, n)	\
-	(((p) >> PAGE_SHIFT) - PLAT_NODE_DATA(n)->gendata.node_start_pfn)
-#else
-static inline unsigned long
-PLAT_NODE_DATA_LOCALNR(unsigned long p, int n)
-{
-	unsigned long temp;
-	temp = p >> PAGE_SHIFT;
-	return temp - PLAT_NODE_DATA(n)->gendata.node_start_pfn;
-}
-#endif
-
-/*
- * Following are macros that each numa implementation must define.
- */
-
-/*
- * Given a kernel address, find the home node of the underlying memory.
- */
-#define kvaddr_to_nid(kaddr)	pa_to_nid(__pa(kaddr))
-
-/*
- * Given a kaddr, LOCAL_BASE_ADDR finds the owning node of the memory
- * and returns the kaddr corresponding to first physical page in the
- * node's mem_map.
- */
-#define LOCAL_BASE_ADDR(kaddr)						  \
-    ((unsigned long)__va(NODE_DATA(kvaddr_to_nid(kaddr))->node_start_pfn  \
-			 << PAGE_SHIFT))
-
-/* XXX: FIXME -- nyc */
-#define kern_addr_valid(kaddr)	(0)
-
-#define mk_pte(page, pgprot)						     \
-({								 	     \
-	pte_t pte;                                                           \
-	unsigned long pfn;                                                   \
-									     \
-	pfn = page_to_pfn(page) << 32; \
-	pte_val(pte) = pfn | pgprot_val(pgprot);			     \
-									     \
-	pte;								     \
-})
-
-#define pte_page(x)							\
-({									\
-       	unsigned long kvirt;						\
-	struct page * __xx;						\
-									\
-	kvirt = (unsigned long)__va(pte_val(x) >> (32-PAGE_SHIFT));	\
-	__xx = virt_to_page(kvirt);					\
-									\
-	__xx;                                                           \
-})
-
-#define pfn_to_nid(pfn)		pa_to_nid(((u64)(pfn) << PAGE_SHIFT))
-#define pfn_valid(pfn)							\
-	(((pfn) - node_start_pfn(pfn_to_nid(pfn))) <			\
-	 node_spanned_pages(pfn_to_nid(pfn)))					\
-
-#endif /* CONFIG_DISCONTIGMEM */
-
-#endif /* _ASM_MMZONE_H_ */
diff --git a/arch/alpha/include/asm/pgtable.h b/arch/alpha/include/asm/pgtable.h
index 8d856c62e22a..e1757b7cfe3d 100644
--- a/arch/alpha/include/asm/pgtable.h
+++ b/arch/alpha/include/asm/pgtable.h
@@ -206,7 +206,6 @@ extern unsigned long __zero_page(void);
 #define page_to_pa(page)	(page_to_pfn(page) << PAGE_SHIFT)
 #define pte_pfn(pte)	(pte_val(pte) >> 32)
 
-#ifndef CONFIG_DISCONTIGMEM
 #define pte_page(pte)	pfn_to_page(pte_pfn(pte))
 #define mk_pte(page, pgprot)						\
 ({									\
@@ -215,7 +214,6 @@ extern unsigned long __zero_page(void);
 	pte_val(pte) = (page_to_pfn(page) << 32) | pgprot_val(pgprot);	\
 	pte;								\
 })
-#endif
 
 extern inline pte_t pfn_pte(unsigned long physpfn, pgprot_t pgprot)
 { pte_t pte; pte_val(pte) = (PHYS_TWIDDLE(physpfn) << 32) | pgprot_val(pgprot); return pte; }
@@ -330,9 +328,7 @@ extern inline pte_t mk_swap_pte(unsigned long type, unsigned long offset)
 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
 #define __swp_entry_to_pte(x)	((pte_t) { (x).val })
 
-#ifndef CONFIG_DISCONTIGMEM
 #define kern_addr_valid(addr)	(1)
-#endif
 
 #define pte_ERROR(e) \
 	printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))
diff --git a/arch/alpha/include/asm/topology.h b/arch/alpha/include/asm/topology.h
index 5a77a40567fa..7d393036aa8f 100644
--- a/arch/alpha/include/asm/topology.h
+++ b/arch/alpha/include/asm/topology.h
@@ -7,45 +7,6 @@
 #include <linux/numa.h>
 #include <asm/machvec.h>
 
-#ifdef CONFIG_NUMA
-static inline int cpu_to_node(int cpu)
-{
-	int node;
-	
-	if (!alpha_mv.cpuid_to_nid)
-		return 0;
-
-	node = alpha_mv.cpuid_to_nid(cpu);
-
-#ifdef DEBUG_NUMA
-	BUG_ON(node < 0);
-#endif
-
-	return node;
-}
-
-extern struct cpumask node_to_cpumask_map[];
-/* FIXME: This is dumb, recalculating every time.  But simple. */
-static const struct cpumask *cpumask_of_node(int node)
-{
-	int cpu;
-
-	if (node == NUMA_NO_NODE)
-		return cpu_all_mask;
-
-	cpumask_clear(&node_to_cpumask_map[node]);
-
-	for_each_online_cpu(cpu) {
-		if (cpu_to_node(cpu) == node)
-			cpumask_set_cpu(cpu, node_to_cpumask_map[node]);
-	}
-
-	return &node_to_cpumask_map[node];
-}
-
-#define cpumask_of_pcibus(bus)	(cpu_online_mask)
-
-#endif /* !CONFIG_NUMA */
 # include <asm-generic/topology.h>
 
 #endif /* _ASM_ALPHA_TOPOLOGY_H */
diff --git a/arch/alpha/kernel/core_marvel.c b/arch/alpha/kernel/core_marvel.c
index 4485b77f8658..1efca79ac83c 100644
--- a/arch/alpha/kernel/core_marvel.c
+++ b/arch/alpha/kernel/core_marvel.c
@@ -287,8 +287,7 @@ io7_init_hose(struct io7 *io7, int port)
 	/*
 	 * Set up window 0 for scatter-gather 8MB at 8MB.
 	 */
-	hose->sg_isa = iommu_arena_new_node(marvel_cpuid_to_nid(io7->pe),
-					    hose, 0x00800000, 0x00800000, 0);
+	hose->sg_isa = iommu_arena_new_node(0, hose, 0x00800000, 0x00800000, 0);
 	hose->sg_isa->align_entry = 8;	/* cache line boundary */
 	csrs->POx_WBASE[0].csr = 
 		hose->sg_isa->dma_base | wbase_m_ena | wbase_m_sg;
@@ -305,8 +304,7 @@ io7_init_hose(struct io7 *io7, int port)
 	/*
 	 * Set up window 2 for scatter-gather (up-to) 1GB at 3GB.
 	 */
-	hose->sg_pci = iommu_arena_new_node(marvel_cpuid_to_nid(io7->pe),
-					    hose, 0xc0000000, 0x40000000, 0);
+	hose->sg_pci = iommu_arena_new_node(0, hose, 0xc0000000, 0x40000000, 0);
 	hose->sg_pci->align_entry = 8;	/* cache line boundary */
 	csrs->POx_WBASE[2].csr = 
 		hose->sg_pci->dma_base | wbase_m_ena | wbase_m_sg;
@@ -843,53 +841,8 @@ EXPORT_SYMBOL(marvel_ioportmap);
 EXPORT_SYMBOL(marvel_ioread8);
 EXPORT_SYMBOL(marvel_iowrite8);
 #endif
-\f
-/*
- * NUMA Support
- */
-/**********
- * FIXME - for now each cpu is a node by itself 
- *              -- no real support for striped mode 
- **********
- */
-int
-marvel_pa_to_nid(unsigned long pa)
-{
-	int cpuid;
 
-	if ((pa >> 43) & 1) 	/* I/O */ 
-		cpuid = (~(pa >> 35) & 0xff);
-	else			/* mem */
-		cpuid = ((pa >> 34) & 0x3) | ((pa >> (37 - 2)) & (0x1f << 2));
-
-	return marvel_cpuid_to_nid(cpuid);
-}
-
-int
-marvel_cpuid_to_nid(int cpuid)
-{
-	return cpuid;
-}
-
-unsigned long
-marvel_node_mem_start(int nid)
-{
-	unsigned long pa;
-
-	pa = (nid & 0x3) | ((nid & (0x1f << 2)) << 1);
-	pa <<= 34;
-
-	return pa;
-}
-
-unsigned long
-marvel_node_mem_size(int nid)
-{
-	return 16UL * 1024 * 1024 * 1024; /* 16GB */
-}
-
-\f
-/* 
+/*
  * AGP GART Support.
  */
 #include <linux/agp_backend.h>
diff --git a/arch/alpha/kernel/core_wildfire.c b/arch/alpha/kernel/core_wildfire.c
index e8d3b033018d..3a804b67f9da 100644
--- a/arch/alpha/kernel/core_wildfire.c
+++ b/arch/alpha/kernel/core_wildfire.c
@@ -434,39 +434,12 @@ wildfire_write_config(struct pci_bus *bus, unsigned int devfn, int where,
 	return PCIBIOS_SUCCESSFUL;
 }
 
-struct pci_ops wildfire_pci_ops = 
+struct pci_ops wildfire_pci_ops =
 {
 	.read =		wildfire_read_config,
 	.write =	wildfire_write_config,
 };
 
-\f
-/*
- * NUMA Support
- */
-int wildfire_pa_to_nid(unsigned long pa)
-{
-	return pa >> 36;
-}
-
-int wildfire_cpuid_to_nid(int cpuid)
-{
-	/* assume 4 CPUs per node */
-	return cpuid >> 2;
-}
-
-unsigned long wildfire_node_mem_start(int nid)
-{
-	/* 64GB per node */
-	return (unsigned long)nid * (64UL * 1024 * 1024 * 1024);
-}
-
-unsigned long wildfire_node_mem_size(int nid)
-{
-	/* 64GB per node */
-	return 64UL * 1024 * 1024 * 1024;
-}
-
 #if DEBUG_DUMP_REGS
 
 static void __init
diff --git a/arch/alpha/kernel/pci_iommu.c b/arch/alpha/kernel/pci_iommu.c
index d84b19aa8e9d..35d7b3096d6e 100644
--- a/arch/alpha/kernel/pci_iommu.c
+++ b/arch/alpha/kernel/pci_iommu.c
@@ -71,33 +71,6 @@ iommu_arena_new_node(int nid, struct pci_controller *hose, dma_addr_t base,
 	if (align < mem_size)
 		align = mem_size;
 
-
-#ifdef CONFIG_DISCONTIGMEM
-
-	arena = memblock_alloc_node(sizeof(*arena), align, nid);
-	if (!NODE_DATA(nid) || !arena) {
-		printk("%s: couldn't allocate arena from node %d\n"
-		       "    falling back to system-wide allocation\n",
-		       __func__, nid);
-		arena = memblock_alloc(sizeof(*arena), SMP_CACHE_BYTES);
-		if (!arena)
-			panic("%s: Failed to allocate %zu bytes\n", __func__,
-			      sizeof(*arena));
-	}
-
-	arena->ptes = memblock_alloc_node(sizeof(*arena), align, nid);
-	if (!NODE_DATA(nid) || !arena->ptes) {
-		printk("%s: couldn't allocate arena ptes from node %d\n"
-		       "    falling back to system-wide allocation\n",
-		       __func__, nid);
-		arena->ptes = memblock_alloc(mem_size, align);
-		if (!arena->ptes)
-			panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
-			      __func__, mem_size, align);
-	}
-
-#else /* CONFIG_DISCONTIGMEM */
-
 	arena = memblock_alloc(sizeof(*arena), SMP_CACHE_BYTES);
 	if (!arena)
 		panic("%s: Failed to allocate %zu bytes\n", __func__,
@@ -107,8 +80,6 @@ iommu_arena_new_node(int nid, struct pci_controller *hose, dma_addr_t base,
 		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
 		      __func__, mem_size, align);
 
-#endif /* CONFIG_DISCONTIGMEM */
-
 	spin_lock_init(&arena->lock);
 	arena->hose = hose;
 	arena->dma_base = base;
diff --git a/arch/alpha/kernel/proto.h b/arch/alpha/kernel/proto.h
index 701a05090141..5816a31c1b38 100644
--- a/arch/alpha/kernel/proto.h
+++ b/arch/alpha/kernel/proto.h
@@ -49,10 +49,6 @@ extern void marvel_init_arch(void);
 extern void marvel_kill_arch(int);
 extern void marvel_machine_check(unsigned long, unsigned long);
 extern void marvel_pci_tbi(struct pci_controller *, dma_addr_t, dma_addr_t);
-extern int marvel_pa_to_nid(unsigned long);
-extern int marvel_cpuid_to_nid(int);
-extern unsigned long marvel_node_mem_start(int);
-extern unsigned long marvel_node_mem_size(int);
 extern struct _alpha_agp_info *marvel_agp_info(void);
 struct io7 *marvel_find_io7(int pe);
 struct io7 *marvel_next_io7(struct io7 *prev);
@@ -101,10 +97,6 @@ extern void wildfire_init_arch(void);
 extern void wildfire_kill_arch(int);
 extern void wildfire_machine_check(unsigned long vector, unsigned long la_ptr);
 extern void wildfire_pci_tbi(struct pci_controller *, dma_addr_t, dma_addr_t);
-extern int wildfire_pa_to_nid(unsigned long);
-extern int wildfire_cpuid_to_nid(int);
-extern unsigned long wildfire_node_mem_start(int);
-extern unsigned long wildfire_node_mem_size(int);
 
 /* console.c */
 #ifdef CONFIG_VGA_HOSE
diff --git a/arch/alpha/kernel/setup.c b/arch/alpha/kernel/setup.c
index 03dda3beb3bd..5f6858e9dc28 100644
--- a/arch/alpha/kernel/setup.c
+++ b/arch/alpha/kernel/setup.c
@@ -79,11 +79,6 @@ int alpha_l3_cacheshape;
 unsigned long alpha_verbose_mcheck = CONFIG_VERBOSE_MCHECK_ON;
 #endif
 
-#ifdef CONFIG_NUMA
-struct cpumask node_to_cpumask_map[MAX_NUMNODES] __read_mostly;
-EXPORT_SYMBOL(node_to_cpumask_map);
-#endif
-
 /* Which processor we booted from.  */
 int boot_cpuid;
 
@@ -305,7 +300,6 @@ move_initrd(unsigned long mem_limit)
 }
 #endif
 
-#ifndef CONFIG_DISCONTIGMEM
 static void __init
 setup_memory(void *kernel_end)
 {
@@ -389,9 +383,6 @@ setup_memory(void *kernel_end)
 	}
 #endif /* CONFIG_BLK_DEV_INITRD */
 }
-#else
-extern void setup_memory(void *);
-#endif /* !CONFIG_DISCONTIGMEM */
 
 int __init
 page_is_ram(unsigned long pfn)
@@ -618,13 +609,6 @@ setup_arch(char **cmdline_p)
 	       "VERBOSE_MCHECK "
 #endif
 
-#ifdef CONFIG_DISCONTIGMEM
-	       "DISCONTIGMEM "
-#ifdef CONFIG_NUMA
-	       "NUMA "
-#endif
-#endif
-
 #ifdef CONFIG_DEBUG_SPINLOCK
 	       "DEBUG_SPINLOCK "
 #endif
diff --git a/arch/alpha/kernel/sys_marvel.c b/arch/alpha/kernel/sys_marvel.c
index 83d6c53d6d4d..1f99b03effc2 100644
--- a/arch/alpha/kernel/sys_marvel.c
+++ b/arch/alpha/kernel/sys_marvel.c
@@ -461,10 +461,5 @@ struct alpha_machine_vector marvel_ev7_mv __initmv = {
 	.kill_arch		= marvel_kill_arch,
 	.pci_map_irq		= marvel_map_irq,
 	.pci_swizzle		= common_swizzle,
-
-	.pa_to_nid		= marvel_pa_to_nid,
-	.cpuid_to_nid		= marvel_cpuid_to_nid,
-	.node_mem_start		= marvel_node_mem_start,
-	.node_mem_size		= marvel_node_mem_size,
 };
 ALIAS_MV(marvel_ev7)
diff --git a/arch/alpha/kernel/sys_wildfire.c b/arch/alpha/kernel/sys_wildfire.c
index 2c54d707142a..3cee05443f07 100644
--- a/arch/alpha/kernel/sys_wildfire.c
+++ b/arch/alpha/kernel/sys_wildfire.c
@@ -337,10 +337,5 @@ struct alpha_machine_vector wildfire_mv __initmv = {
 	.kill_arch		= wildfire_kill_arch,
 	.pci_map_irq		= wildfire_map_irq,
 	.pci_swizzle		= common_swizzle,
-
-	.pa_to_nid		= wildfire_pa_to_nid,
-	.cpuid_to_nid		= wildfire_cpuid_to_nid,
-	.node_mem_start		= wildfire_node_mem_start,
-	.node_mem_size		= wildfire_node_mem_size,
 };
 ALIAS_MV(wildfire)
diff --git a/arch/alpha/mm/Makefile b/arch/alpha/mm/Makefile
index 08ac6612edad..bd770302eb82 100644
--- a/arch/alpha/mm/Makefile
+++ b/arch/alpha/mm/Makefile
@@ -6,5 +6,3 @@
 ccflags-y := -Werror
 
 obj-y	:= init.o fault.o
-
-obj-$(CONFIG_DISCONTIGMEM) += numa.o
diff --git a/arch/alpha/mm/init.c b/arch/alpha/mm/init.c
index a97650a618f1..f6114d03357c 100644
--- a/arch/alpha/mm/init.c
+++ b/arch/alpha/mm/init.c
@@ -235,8 +235,6 @@ callback_init(void * kernel_end)
 	return kernel_end;
 }
 
-
-#ifndef CONFIG_DISCONTIGMEM
 /*
  * paging_init() sets up the memory map.
  */
@@ -257,7 +255,6 @@ void __init paging_init(void)
 	/* Initialize the kernel's ZERO_PGE. */
 	memset((void *)ZERO_PGE, 0, PAGE_SIZE);
 }
-#endif /* CONFIG_DISCONTIGMEM */
 
 #if defined(CONFIG_ALPHA_GENERIC) || defined(CONFIG_ALPHA_SRM)
 void
diff --git a/arch/alpha/mm/numa.c b/arch/alpha/mm/numa.c
deleted file mode 100644
index 0636e254a22f..000000000000
--- a/arch/alpha/mm/numa.c
+++ /dev/null
@@ -1,223 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- *  linux/arch/alpha/mm/numa.c
- *
- *  DISCONTIGMEM NUMA alpha support.
- *
- *  Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE
- */
-
-#include <linux/types.h>
-#include <linux/kernel.h>
-#include <linux/mm.h>
-#include <linux/memblock.h>
-#include <linux/swap.h>
-#include <linux/initrd.h>
-#include <linux/pfn.h>
-#include <linux/module.h>
-
-#include <asm/hwrpb.h>
-#include <asm/sections.h>
-
-pg_data_t node_data[MAX_NUMNODES];
-EXPORT_SYMBOL(node_data);
-
-#undef DEBUG_DISCONTIG
-#ifdef DEBUG_DISCONTIG
-#define DBGDCONT(args...) printk(args)
-#else
-#define DBGDCONT(args...)
-#endif
-
-#define for_each_mem_cluster(memdesc, _cluster, i)		\
-	for ((_cluster) = (memdesc)->cluster, (i) = 0;		\
-	     (i) < (memdesc)->numclusters; (i)++, (_cluster)++)
-
-static void __init show_mem_layout(void)
-{
-	struct memclust_struct * cluster;
-	struct memdesc_struct * memdesc;
-	int i;
-
-	/* Find free clusters, and init and free the bootmem accordingly.  */
-	memdesc = (struct memdesc_struct *)
-	  (hwrpb->mddt_offset + (unsigned long) hwrpb);
-
-	printk("Raw memory layout:\n");
-	for_each_mem_cluster(memdesc, cluster, i) {
-		printk(" memcluster %2d, usage %1lx, start %8lu, end %8lu\n",
-		       i, cluster->usage, cluster->start_pfn,
-		       cluster->start_pfn + cluster->numpages);
-	}
-}
-
-static void __init
-setup_memory_node(int nid, void *kernel_end)
-{
-	extern unsigned long mem_size_limit;
-	struct memclust_struct * cluster;
-	struct memdesc_struct * memdesc;
-	unsigned long start_kernel_pfn, end_kernel_pfn;
-	unsigned long start, end;
-	unsigned long node_pfn_start, node_pfn_end;
-	unsigned long node_min_pfn, node_max_pfn;
-	int i;
-	int show_init = 0;
-
-	/* Find the bounds of current node */
-	node_pfn_start = (node_mem_start(nid)) >> PAGE_SHIFT;
-	node_pfn_end = node_pfn_start + (node_mem_size(nid) >> PAGE_SHIFT);
-	
-	/* Find free clusters, and init and free the bootmem accordingly.  */
-	memdesc = (struct memdesc_struct *)
-	  (hwrpb->mddt_offset + (unsigned long) hwrpb);
-
-	/* find the bounds of this node (node_min_pfn/node_max_pfn) */
-	node_min_pfn = ~0UL;
-	node_max_pfn = 0UL;
-	for_each_mem_cluster(memdesc, cluster, i) {
-		/* Bit 0 is console/PALcode reserved.  Bit 1 is
-		   non-volatile memory -- we might want to mark
-		   this for later.  */
-		if (cluster->usage & 3)
-			continue;
-
-		start = cluster->start_pfn;
-		end = start + cluster->numpages;
-
-		if (start >= node_pfn_end || end <= node_pfn_start)
-			continue;
-
-		if (!show_init) {
-			show_init = 1;
-			printk("Initializing bootmem allocator on Node ID %d\n", nid);
-		}
-		printk(" memcluster %2d, usage %1lx, start %8lu, end %8lu\n",
-		       i, cluster->usage, cluster->start_pfn,
-		       cluster->start_pfn + cluster->numpages);
-
-		if (start < node_pfn_start)
-			start = node_pfn_start;
-		if (end > node_pfn_end)
-			end = node_pfn_end;
-
-		if (start < node_min_pfn)
-			node_min_pfn = start;
-		if (end > node_max_pfn)
-			node_max_pfn = end;
-	}
-
-	if (mem_size_limit && node_max_pfn > mem_size_limit) {
-		static int msg_shown = 0;
-		if (!msg_shown) {
-			msg_shown = 1;
-			printk("setup: forcing memory size to %ldK (from %ldK).\n",
-			       mem_size_limit << (PAGE_SHIFT - 10),
-			       node_max_pfn    << (PAGE_SHIFT - 10));
-		}
-		node_max_pfn = mem_size_limit;
-	}
-
-	if (node_min_pfn >= node_max_pfn)
-		return;
-
-	/* Update global {min,max}_low_pfn from node information. */
-	if (node_min_pfn < min_low_pfn)
-		min_low_pfn = node_min_pfn;
-	if (node_max_pfn > max_low_pfn)
-		max_pfn = max_low_pfn = node_max_pfn;
-
-#if 0 /* we'll try this one again in a little while */
-	/* Cute trick to make sure our local node data is on local memory */
-	node_data[nid] = (pg_data_t *)(__va(node_min_pfn << PAGE_SHIFT));
-#endif
-	printk(" Detected node memory:   start %8lu, end %8lu\n",
-	       node_min_pfn, node_max_pfn);
-
-	DBGDCONT(" DISCONTIG: node_data[%d]   is at 0x%p\n", nid, NODE_DATA(nid));
-
-	/* Find the bounds of kernel memory.  */
-	start_kernel_pfn = PFN_DOWN(KERNEL_START_PHYS);
-	end_kernel_pfn = PFN_UP(virt_to_phys(kernel_end));
-
-	if (!nid && (node_max_pfn < end_kernel_pfn || node_min_pfn > start_kernel_pfn))
-		panic("kernel loaded out of ram");
-
-	memblock_add_node(PFN_PHYS(node_min_pfn),
-			  (node_max_pfn - node_min_pfn) << PAGE_SHIFT, nid);
-
-	/* Zone start phys-addr must be 2^(MAX_ORDER-1) aligned.
-	   Note that we round this down, not up - node memory
-	   has much larger alignment than 8Mb, so it's safe. */
-	node_min_pfn &= ~((1UL << (MAX_ORDER-1))-1);
-
-	NODE_DATA(nid)->node_start_pfn = node_min_pfn;
-	NODE_DATA(nid)->node_present_pages = node_max_pfn - node_min_pfn;
-
-	node_set_online(nid);
-}
-
-void __init
-setup_memory(void *kernel_end)
-{
-	unsigned long kernel_size;
-	int nid;
-
-	show_mem_layout();
-
-	nodes_clear(node_online_map);
-
-	min_low_pfn = ~0UL;
-	max_low_pfn = 0UL;
-	for (nid = 0; nid < MAX_NUMNODES; nid++)
-		setup_memory_node(nid, kernel_end);
-
-	kernel_size = virt_to_phys(kernel_end) - KERNEL_START_PHYS;
-	memblock_reserve(KERNEL_START_PHYS, kernel_size);
-
-#ifdef CONFIG_BLK_DEV_INITRD
-	initrd_start = INITRD_START;
-	if (initrd_start) {
-		extern void *move_initrd(unsigned long);
-
-		initrd_end = initrd_start+INITRD_SIZE;
-		printk("Initial ramdisk at: 0x%p (%lu bytes)\n",
-		       (void *) initrd_start, INITRD_SIZE);
-
-		if ((void *)initrd_end > phys_to_virt(PFN_PHYS(max_low_pfn))) {
-			if (!move_initrd(PFN_PHYS(max_low_pfn)))
-				printk("initrd extends beyond end of memory "
-				       "(0x%08lx > 0x%p)\ndisabling initrd\n",
-				       initrd_end,
-				       phys_to_virt(PFN_PHYS(max_low_pfn)));
-		} else {
-			nid = kvaddr_to_nid(initrd_start);
-			memblock_reserve(virt_to_phys((void *)initrd_start),
-					 INITRD_SIZE);
-		}
-	}
-#endif /* CONFIG_BLK_DEV_INITRD */
-}
-
-void __init paging_init(void)
-{
-	unsigned long   max_zone_pfn[MAX_NR_ZONES] = {0, };
-	unsigned long	dma_local_pfn;
-
-	/*
-	 * The old global MAX_DMA_ADDRESS per-arch API doesn't fit
-	 * in the NUMA model, for now we convert it to a pfn and
-	 * we interpret this pfn as a local per-node information.
-	 * This issue isn't very important since none of these machines
-	 * have legacy ISA slots anyways.
-	 */
-	dma_local_pfn = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
-
-	max_zone_pfn[ZONE_DMA] = dma_local_pfn;
-	max_zone_pfn[ZONE_NORMAL] = max_pfn;
-
-	free_area_init(max_zone_pfn);
-
-	/* Initialize the kernel's ZERO_PGE. */
-	memset((void *)ZERO_PGE, 0, PAGE_SIZE);
-}
-- 
2.28.0

[PATCH v2 2/9] arc: update comment about HIGHMEM implementation

[Mike Rapoport]

From: Mike Rapoport <rppt@linux.ibm.com>

Arc does not use DISCONTIGMEM to implement high memory, update the comment
describing how high memory works to reflect this.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
---
 arch/arc/mm/init.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
index e2ed355438c9..397a201adfe3 100644
--- a/arch/arc/mm/init.c
+++ b/arch/arc/mm/init.c
@@ -139,16 +139,13 @@ void __init setup_arch_memory(void)
 
 #ifdef CONFIG_HIGHMEM
 	/*
-	 * Populate a new node with highmem
-	 *
 	 * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based)
-	 * than addresses in normal ala low memory (0x8000_0000 based).
+	 * than addresses in normal aka low memory (0x8000_0000 based).
 	 * Even with PAE, the huge peripheral space hole would waste a lot of
-	 * mem with single mem_map[]. This warrants a mem_map per region design.
-	 * Thus HIGHMEM on ARC is imlemented with DISCONTIGMEM.
-	 *
-	 * DISCONTIGMEM in turns requires multiple nodes. node 0 above is
-	 * populated with normal memory zone while node 1 only has highmem
+	 * mem with single contiguous mem_map[].
+	 * Thus when HIGHMEM on ARC is enabled the memory map corresponding
+	 * to the hole is freed and ARC specific version of pfn_valid()
+	 * handles the hole in the memory map.
 	 */
 #ifdef CONFIG_DISCONTIGMEM
 	node_set_online(1);
-- 
2.28.0

Re: [PATCH v2 2/9] arc: update comment about HIGHMEM implementation

[Vineet Gupta]

On 6/3/21 11:49 PM, Mike Rapoport wrote:
> From: Mike Rapoport <rppt@linux.ibm.com>
>
> Arc does not use DISCONTIGMEM to implement high memory, update the comment
> describing how high memory works to reflect this.
>
> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>

Acked-by: Vineet Gupta <vgupta@synopsys.com>

Thx,
-Vineet

> ---
>   arch/arc/mm/init.c | 13 +++++--------
>   1 file changed, 5 insertions(+), 8 deletions(-)
>
> diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
> index e2ed355438c9..397a201adfe3 100644
> --- a/arch/arc/mm/init.c
> +++ b/arch/arc/mm/init.c
> @@ -139,16 +139,13 @@ void __init setup_arch_memory(void)
>   
>   #ifdef CONFIG_HIGHMEM
>   	/*
> -	 * Populate a new node with highmem
> -	 *
>   	 * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based)
> -	 * than addresses in normal ala low memory (0x8000_0000 based).
> +	 * than addresses in normal aka low memory (0x8000_0000 based).
>   	 * Even with PAE, the huge peripheral space hole would waste a lot of
> -	 * mem with single mem_map[]. This warrants a mem_map per region design.
> -	 * Thus HIGHMEM on ARC is imlemented with DISCONTIGMEM.
> -	 *
> -	 * DISCONTIGMEM in turns requires multiple nodes. node 0 above is
> -	 * populated with normal memory zone while node 1 only has highmem
> +	 * mem with single contiguous mem_map[].
> +	 * Thus when HIGHMEM on ARC is enabled the memory map corresponding
> +	 * to the hole is freed and ARC specific version of pfn_valid()
> +	 * handles the hole in the memory map.
>   	 */
>   #ifdef CONFIG_DISCONTIGMEM
>   	node_set_online(1);

[PATCH v2 3/9] arc: remove support for DISCONTIGMEM

[Mike Rapoport]

From: Mike Rapoport <rppt@linux.ibm.com>

DISCONTIGMEM was replaced by FLATMEM with freeing of the unused memory map
in v5.11.

Remove the support for DISCONTIGMEM entirely.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
---
 arch/arc/Kconfig              | 13 ------------
 arch/arc/include/asm/mmzone.h | 40 -----------------------------------
 arch/arc/mm/init.c            |  8 -------
 3 files changed, 61 deletions(-)
 delete mode 100644 arch/arc/include/asm/mmzone.h

diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 2d98501c0897..d8f51eb8963b 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -62,10 +62,6 @@ config SCHED_OMIT_FRAME_POINTER
 config GENERIC_CSUM
 	def_bool y
 
-config ARCH_DISCONTIGMEM_ENABLE
-	def_bool n
-	depends on BROKEN
-
 config ARCH_FLATMEM_ENABLE
 	def_bool y
 
@@ -344,15 +340,6 @@ config ARC_HUGEPAGE_16M
 
 endchoice
 
-config NODES_SHIFT
-	int "Maximum NUMA Nodes (as a power of 2)"
-	default "0" if !DISCONTIGMEM
-	default "1" if DISCONTIGMEM
-	depends on NEED_MULTIPLE_NODES
-	help
-	  Accessing memory beyond 1GB (with or w/o PAE) requires 2 memory
-	  zones.
-
 config ARC_COMPACT_IRQ_LEVELS
 	depends on ISA_ARCOMPACT
 	bool "Setup Timer IRQ as high Priority"
diff --git a/arch/arc/include/asm/mmzone.h b/arch/arc/include/asm/mmzone.h
deleted file mode 100644
index b86b9d1e54dc..000000000000
--- a/arch/arc/include/asm/mmzone.h
+++ /dev/null
@@ -1,40 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Copyright (C) 2016 Synopsys, Inc. (www.synopsys.com)
- */
-
-#ifndef _ASM_ARC_MMZONE_H
-#define _ASM_ARC_MMZONE_H
-
-#ifdef CONFIG_DISCONTIGMEM
-
-extern struct pglist_data node_data[];
-#define NODE_DATA(nid) (&node_data[nid])
-
-static inline int pfn_to_nid(unsigned long pfn)
-{
-	int is_end_low = 1;
-
-	if (IS_ENABLED(CONFIG_ARC_HAS_PAE40))
-		is_end_low = pfn <= virt_to_pfn(0xFFFFFFFFUL);
-
-	/*
-	 * node 0: lowmem:             0x8000_0000   to 0xFFFF_FFFF
-	 * node 1: HIGHMEM w/o  PAE40: 0x0           to 0x7FFF_FFFF
-	 *         HIGHMEM with PAE40: 0x1_0000_0000 to ...
-	 */
-	if (pfn >= ARCH_PFN_OFFSET && is_end_low)
-		return 0;
-
-	return 1;
-}
-
-static inline int pfn_valid(unsigned long pfn)
-{
-	int nid = pfn_to_nid(pfn);
-
-	return (pfn <= node_end_pfn(nid));
-}
-#endif /* CONFIG_DISCONTIGMEM  */
-
-#endif
diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
index 397a201adfe3..abfeef7bf6f8 100644
--- a/arch/arc/mm/init.c
+++ b/arch/arc/mm/init.c
@@ -32,11 +32,6 @@ unsigned long arch_pfn_offset;
 EXPORT_SYMBOL(arch_pfn_offset);
 #endif
 
-#ifdef CONFIG_DISCONTIGMEM
-struct pglist_data node_data[MAX_NUMNODES] __read_mostly;
-EXPORT_SYMBOL(node_data);
-#endif
-
 long __init arc_get_mem_sz(void)
 {
 	return low_mem_sz;
@@ -147,9 +142,6 @@ void __init setup_arch_memory(void)
 	 * to the hole is freed and ARC specific version of pfn_valid()
 	 * handles the hole in the memory map.
 	 */
-#ifdef CONFIG_DISCONTIGMEM
-	node_set_online(1);
-#endif
 
 	min_high_pfn = PFN_DOWN(high_mem_start);
 	max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
-- 
2.28.0

Re: [PATCH v2 3/9] arc: remove support for DISCONTIGMEM

[Vineet Gupta]

On 6/3/21 11:49 PM, Mike Rapoport wrote:
> From: Mike Rapoport <rppt@linux.ibm.com>
>
> DISCONTIGMEM was replaced by FLATMEM with freeing of the unused memory map
> in v5.11.
>
> Remove the support for DISCONTIGMEM entirely.
>
> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>

Looks non intrusive, but I'd still like to give this a spin on hardware 
- considering highmem on ARC has tendency to go sideways ;-)
Can you please share a branch !

Acked-by: Vineet Gupta <vgupta@synopsys.com>

Thx,
-Vineet

> ---
>   arch/arc/Kconfig              | 13 ------------
>   arch/arc/include/asm/mmzone.h | 40 -----------------------------------
>   arch/arc/mm/init.c            |  8 -------
>   3 files changed, 61 deletions(-)
>   delete mode 100644 arch/arc/include/asm/mmzone.h
>
> diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
> index 2d98501c0897..d8f51eb8963b 100644
> --- a/arch/arc/Kconfig
> +++ b/arch/arc/Kconfig
> @@ -62,10 +62,6 @@ config SCHED_OMIT_FRAME_POINTER
>   config GENERIC_CSUM
>   	def_bool y
>   
> -config ARCH_DISCONTIGMEM_ENABLE
> -	def_bool n
> -	depends on BROKEN
> -
>   config ARCH_FLATMEM_ENABLE
>   	def_bool y
>   
> @@ -344,15 +340,6 @@ config ARC_HUGEPAGE_16M
>   
>   endchoice
>   
> -config NODES_SHIFT
> -	int "Maximum NUMA Nodes (as a power of 2)"
> -	default "0" if !DISCONTIGMEM
> -	default "1" if DISCONTIGMEM
> -	depends on NEED_MULTIPLE_NODES
> -	help
> -	  Accessing memory beyond 1GB (with or w/o PAE) requires 2 memory
> -	  zones.
> -
>   config ARC_COMPACT_IRQ_LEVELS
>   	depends on ISA_ARCOMPACT
>   	bool "Setup Timer IRQ as high Priority"
> diff --git a/arch/arc/include/asm/mmzone.h b/arch/arc/include/asm/mmzone.h
> deleted file mode 100644
> index b86b9d1e54dc..000000000000
> --- a/arch/arc/include/asm/mmzone.h
> +++ /dev/null
> @@ -1,40 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0-only */
> -/*
> - * Copyright (C) 2016 Synopsys, Inc. (www.synopsys.com)
> - */
> -
> -#ifndef _ASM_ARC_MMZONE_H
> -#define _ASM_ARC_MMZONE_H
> -
> -#ifdef CONFIG_DISCONTIGMEM
> -
> -extern struct pglist_data node_data[];
> -#define NODE_DATA(nid) (&node_data[nid])
> -
> -static inline int pfn_to_nid(unsigned long pfn)
> -{
> -	int is_end_low = 1;
> -
> -	if (IS_ENABLED(CONFIG_ARC_HAS_PAE40))
> -		is_end_low = pfn <= virt_to_pfn(0xFFFFFFFFUL);
> -
> -	/*
> -	 * node 0: lowmem:             0x8000_0000   to 0xFFFF_FFFF
> -	 * node 1: HIGHMEM w/o  PAE40: 0x0           to 0x7FFF_FFFF
> -	 *         HIGHMEM with PAE40: 0x1_0000_0000 to ...
> -	 */
> -	if (pfn >= ARCH_PFN_OFFSET && is_end_low)
> -		return 0;
> -
> -	return 1;
> -}
> -
> -static inline int pfn_valid(unsigned long pfn)
> -{
> -	int nid = pfn_to_nid(pfn);
> -
> -	return (pfn <= node_end_pfn(nid));
> -}
> -#endif /* CONFIG_DISCONTIGMEM  */
> -
> -#endif
> diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
> index 397a201adfe3..abfeef7bf6f8 100644
> --- a/arch/arc/mm/init.c
> +++ b/arch/arc/mm/init.c
> @@ -32,11 +32,6 @@ unsigned long arch_pfn_offset;
>   EXPORT_SYMBOL(arch_pfn_offset);
>   #endif
>   
> -#ifdef CONFIG_DISCONTIGMEM
> -struct pglist_data node_data[MAX_NUMNODES] __read_mostly;
> -EXPORT_SYMBOL(node_data);
> -#endif
> -
>   long __init arc_get_mem_sz(void)
>   {
>   	return low_mem_sz;
> @@ -147,9 +142,6 @@ void __init setup_arch_memory(void)
>   	 * to the hole is freed and ARC specific version of pfn_valid()
>   	 * handles the hole in the memory map.
>   	 */
> -#ifdef CONFIG_DISCONTIGMEM
> -	node_set_online(1);
> -#endif
>   
>   	min_high_pfn = PFN_DOWN(high_mem_start);
>   	max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz);

Re: [PATCH v2 3/9] arc: remove support for DISCONTIGMEM

[Mike Rapoport]

On Fri, Jun 04, 2021 at 02:07:39PM +0000, Vineet Gupta wrote:
> On 6/3/21 11:49 PM, Mike Rapoport wrote:
> > From: Mike Rapoport <rppt@linux.ibm.com>
> >
> > DISCONTIGMEM was replaced by FLATMEM with freeing of the unused memory map
> > in v5.11.
> >
> > Remove the support for DISCONTIGMEM entirely.
> >
> > Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
> 
> Looks non intrusive, but I'd still like to give this a spin on hardware 
> - considering highmem on ARC has tendency to go sideways ;-)
> Can you please share a branch !

Sure:

https://git.kernel.org/pub/scm/linux/kernel/git/rppt/linux.git/log/?h=memory-models/rm-discontig/v2
 
> Acked-by: Vineet Gupta <vgupta@synopsys.com>

Thanks!
 
> Thx,
> -Vineet
> 
> > ---
> >   arch/arc/Kconfig              | 13 ------------
> >   arch/arc/include/asm/mmzone.h | 40 -----------------------------------
> >   arch/arc/mm/init.c            |  8 -------
> >   3 files changed, 61 deletions(-)
> >   delete mode 100644 arch/arc/include/asm/mmzone.h
> >
> > diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
> > index 2d98501c0897..d8f51eb8963b 100644
> > --- a/arch/arc/Kconfig
> > +++ b/arch/arc/Kconfig
> > @@ -62,10 +62,6 @@ config SCHED_OMIT_FRAME_POINTER
> >   config GENERIC_CSUM
> >   	def_bool y
> >   
> > -config ARCH_DISCONTIGMEM_ENABLE
> > -	def_bool n
> > -	depends on BROKEN
> > -
> >   config ARCH_FLATMEM_ENABLE
> >   	def_bool y
> >   
> > @@ -344,15 +340,6 @@ config ARC_HUGEPAGE_16M
> >   
> >   endchoice
> >   
> > -config NODES_SHIFT
> > -	int "Maximum NUMA Nodes (as a power of 2)"
> > -	default "0" if !DISCONTIGMEM
> > -	default "1" if DISCONTIGMEM
> > -	depends on NEED_MULTIPLE_NODES
> > -	help
> > -	  Accessing memory beyond 1GB (with or w/o PAE) requires 2 memory
> > -	  zones.
> > -
> >   config ARC_COMPACT_IRQ_LEVELS
> >   	depends on ISA_ARCOMPACT
> >   	bool "Setup Timer IRQ as high Priority"
> > diff --git a/arch/arc/include/asm/mmzone.h b/arch/arc/include/asm/mmzone.h
> > deleted file mode 100644
> > index b86b9d1e54dc..000000000000
> > --- a/arch/arc/include/asm/mmzone.h
> > +++ /dev/null
> > @@ -1,40 +0,0 @@
> > -/* SPDX-License-Identifier: GPL-2.0-only */
> > -/*
> > - * Copyright (C) 2016 Synopsys, Inc. (www.synopsys.com)
> > - */
> > -
> > -#ifndef _ASM_ARC_MMZONE_H
> > -#define _ASM_ARC_MMZONE_H
> > -
> > -#ifdef CONFIG_DISCONTIGMEM
> > -
> > -extern struct pglist_data node_data[];
> > -#define NODE_DATA(nid) (&node_data[nid])
> > -
> > -static inline int pfn_to_nid(unsigned long pfn)
> > -{
> > -	int is_end_low = 1;
> > -
> > -	if (IS_ENABLED(CONFIG_ARC_HAS_PAE40))
> > -		is_end_low = pfn <= virt_to_pfn(0xFFFFFFFFUL);
> > -
> > -	/*
> > -	 * node 0: lowmem:             0x8000_0000   to 0xFFFF_FFFF
> > -	 * node 1: HIGHMEM w/o  PAE40: 0x0           to 0x7FFF_FFFF
> > -	 *         HIGHMEM with PAE40: 0x1_0000_0000 to ...
> > -	 */
> > -	if (pfn >= ARCH_PFN_OFFSET && is_end_low)
> > -		return 0;
> > -
> > -	return 1;
> > -}
> > -
> > -static inline int pfn_valid(unsigned long pfn)
> > -{
> > -	int nid = pfn_to_nid(pfn);
> > -
> > -	return (pfn <= node_end_pfn(nid));
> > -}
> > -#endif /* CONFIG_DISCONTIGMEM  */
> > -
> > -#endif
> > diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
> > index 397a201adfe3..abfeef7bf6f8 100644
> > --- a/arch/arc/mm/init.c
> > +++ b/arch/arc/mm/init.c
> > @@ -32,11 +32,6 @@ unsigned long arch_pfn_offset;
> >   EXPORT_SYMBOL(arch_pfn_offset);
> >   #endif
> >   
> > -#ifdef CONFIG_DISCONTIGMEM
> > -struct pglist_data node_data[MAX_NUMNODES] __read_mostly;
> > -EXPORT_SYMBOL(node_data);
> > -#endif
> > -
> >   long __init arc_get_mem_sz(void)
> >   {
> >   	return low_mem_sz;
> > @@ -147,9 +142,6 @@ void __init setup_arch_memory(void)
> >   	 * to the hole is freed and ARC specific version of pfn_valid()
> >   	 * handles the hole in the memory map.
> >   	 */
> > -#ifdef CONFIG_DISCONTIGMEM
> > -	node_set_online(1);
> > -#endif
> >   
> >   	min_high_pfn = PFN_DOWN(high_mem_start);
> >   	max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
> 

-- 
Sincerely yours,
Mike.

[PATCH v2 4/9] m68k: remove support for DISCONTIGMEM

[Mike Rapoport]

From: Mike Rapoport <rppt@linux.ibm.com>

DISCONTIGMEM was replaced by FLATMEM with freeing of the unused memory map
in v5.11.

Remove the support for DISCONTIGMEM entirely.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
 arch/m68k/Kconfig.cpu           | 10 ----------
 arch/m68k/include/asm/mmzone.h  | 10 ----------
 arch/m68k/include/asm/page.h    |  2 +-
 arch/m68k/include/asm/page_mm.h | 35 ---------------------------------
 arch/m68k/mm/init.c             | 20 -------------------
 5 files changed, 1 insertion(+), 76 deletions(-)
 delete mode 100644 arch/m68k/include/asm/mmzone.h

diff --git a/arch/m68k/Kconfig.cpu b/arch/m68k/Kconfig.cpu
index f4d23977d2a5..29e946394fdb 100644
--- a/arch/m68k/Kconfig.cpu
+++ b/arch/m68k/Kconfig.cpu
@@ -408,10 +408,6 @@ config SINGLE_MEMORY_CHUNK
 	  order" to save memory that could be wasted for unused memory map.
 	  Say N if not sure.
 
-config ARCH_DISCONTIGMEM_ENABLE
-	depends on BROKEN
-	def_bool MMU && !SINGLE_MEMORY_CHUNK
-
 config FORCE_MAX_ZONEORDER
 	int "Maximum zone order" if ADVANCED
 	depends on !SINGLE_MEMORY_CHUNK
@@ -451,11 +447,6 @@ config M68K_L2_CACHE
 	depends on MAC
 	default y
 
-config NODES_SHIFT
-	int
-	default "3"
-	depends on DISCONTIGMEM
-
 config CPU_HAS_NO_BITFIELDS
 	bool
 
@@ -553,4 +544,3 @@ config CACHE_COPYBACK
 	  The ColdFire CPU cache is set into Copy-back mode.
 endchoice
 endif
-
diff --git a/arch/m68k/include/asm/mmzone.h b/arch/m68k/include/asm/mmzone.h
deleted file mode 100644
index 64573fe8e60d..000000000000
--- a/arch/m68k/include/asm/mmzone.h
+++ /dev/null
@@ -1,10 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_M68K_MMZONE_H_
-#define _ASM_M68K_MMZONE_H_
-
-extern pg_data_t pg_data_map[];
-
-#define NODE_DATA(nid)		(&pg_data_map[nid])
-#define NODE_MEM_MAP(nid)	(NODE_DATA(nid)->node_mem_map)
-
-#endif /* _ASM_M68K_MMZONE_H_ */
diff --git a/arch/m68k/include/asm/page.h b/arch/m68k/include/asm/page.h
index 97087dd3ca6d..2f1c54e4725d 100644
--- a/arch/m68k/include/asm/page.h
+++ b/arch/m68k/include/asm/page.h
@@ -62,7 +62,7 @@ extern unsigned long _ramend;
 #include <asm/page_no.h>
 #endif
 
-#if !defined(CONFIG_MMU) || defined(CONFIG_DISCONTIGMEM)
+#ifndef CONFIG_MMU
 #define __phys_to_pfn(paddr)	((unsigned long)((paddr) >> PAGE_SHIFT))
 #define __pfn_to_phys(pfn)	PFN_PHYS(pfn)
 #endif
diff --git a/arch/m68k/include/asm/page_mm.h b/arch/m68k/include/asm/page_mm.h
index 2411ea9ef578..a5b459bcb7d8 100644
--- a/arch/m68k/include/asm/page_mm.h
+++ b/arch/m68k/include/asm/page_mm.h
@@ -126,26 +126,6 @@ static inline void *__va(unsigned long x)
 
 extern int m68k_virt_to_node_shift;
 
-#ifndef CONFIG_DISCONTIGMEM
-#define __virt_to_node(addr)	(&pg_data_map[0])
-#else
-extern struct pglist_data *pg_data_table[];
-
-static inline __attribute_const__ int __virt_to_node_shift(void)
-{
-	int shift;
-
-	asm (
-		"1:	moveq	#0,%0\n"
-		m68k_fixup(%c1, 1b)
-		: "=d" (shift)
-		: "i" (m68k_fixup_vnode_shift));
-	return shift;
-}
-
-#define __virt_to_node(addr)	(pg_data_table[(unsigned long)(addr) >> __virt_to_node_shift()])
-#endif
-
 #define virt_to_page(addr) ({						\
 	pfn_to_page(virt_to_pfn(addr));					\
 })
@@ -153,23 +133,8 @@ static inline __attribute_const__ int __virt_to_node_shift(void)
 	pfn_to_virt(page_to_pfn(page));					\
 })
 
-#ifdef CONFIG_DISCONTIGMEM
-#define pfn_to_page(pfn) ({						\
-	unsigned long __pfn = (pfn);					\
-	struct pglist_data *pgdat;					\
-	pgdat = __virt_to_node((unsigned long)pfn_to_virt(__pfn));	\
-	pgdat->node_mem_map + (__pfn - pgdat->node_start_pfn);		\
-})
-#define page_to_pfn(_page) ({						\
-	const struct page *__p = (_page);				\
-	struct pglist_data *pgdat;					\
-	pgdat = &pg_data_map[page_to_nid(__p)];				\
-	((__p) - pgdat->node_mem_map) + pgdat->node_start_pfn;		\
-})
-#else
 #define ARCH_PFN_OFFSET (m68k_memory[0].addr >> PAGE_SHIFT)
 #include <asm-generic/memory_model.h>
-#endif
 
 #define virt_addr_valid(kaddr)	((unsigned long)(kaddr) >= PAGE_OFFSET && (unsigned long)(kaddr) < (unsigned long)high_memory)
 #define pfn_valid(pfn)		virt_addr_valid(pfn_to_virt(pfn))
diff --git a/arch/m68k/mm/init.c b/arch/m68k/mm/init.c
index 1759ab875d47..5d749e188246 100644
--- a/arch/m68k/mm/init.c
+++ b/arch/m68k/mm/init.c
@@ -44,28 +44,8 @@ EXPORT_SYMBOL(empty_zero_page);
 
 int m68k_virt_to_node_shift;
 
-#ifdef CONFIG_DISCONTIGMEM
-pg_data_t pg_data_map[MAX_NUMNODES];
-EXPORT_SYMBOL(pg_data_map);
-
-pg_data_t *pg_data_table[65];
-EXPORT_SYMBOL(pg_data_table);
-#endif
-
 void __init m68k_setup_node(int node)
 {
-#ifdef CONFIG_DISCONTIGMEM
-	struct m68k_mem_info *info = m68k_memory + node;
-	int i, end;
-
-	i = (unsigned long)phys_to_virt(info->addr) >> __virt_to_node_shift();
-	end = (unsigned long)phys_to_virt(info->addr + info->size - 1) >> __virt_to_node_shift();
-	for (; i <= end; i++) {
-		if (pg_data_table[i])
-			pr_warn("overlap at %u for chunk %u\n", i, node);
-		pg_data_table[i] = pg_data_map + node;
-	}
-#endif
 	node_set_online(node);
 }
 
-- 
2.28.0

[PATCH v2 5/9] mm: remove CONFIG_DISCONTIGMEM

[Mike Rapoport]

From: Mike Rapoport <rppt@linux.ibm.com>

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 <rppt@linux.ibm.com>
---
 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
 	def_bool y
-	depends on DISCONTIGMEM || NUMA
+	depends on NUMA
 
 #
 # SPARSEMEM_EXTREME (which is the default) does some bootmem
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index aaa1655cf682..6fc22482eaa8 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -331,20 +331,7 @@ compound_page_dtor * const compound_page_dtors[NR_COMPOUND_DTORS] = {
 
 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;
-- 
2.28.0

[PATCH v2 6/9] arch, mm: remove stale mentions of DISCONIGMEM

[Mike Rapoport]

From: Mike Rapoport <rppt@linux.ibm.com>

There are several places that mention DISCONIGMEM in comments or have stale
code guarded by CONFIG_DISCONTIGMEM.

Remove the dead code and update the comments.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
---
 arch/ia64/kernel/topology.c     | 5 ++---
 arch/ia64/mm/numa.c             | 5 ++---
 arch/mips/include/asm/mmzone.h  | 6 ------
 arch/mips/mm/init.c             | 3 ---
 arch/nds32/include/asm/memory.h | 6 ------
 arch/xtensa/include/asm/page.h  | 4 ----
 include/linux/gfp.h             | 4 ++--
 7 files changed, 6 insertions(+), 27 deletions(-)

diff --git a/arch/ia64/kernel/topology.c b/arch/ia64/kernel/topology.c
index 09fc385c2acd..3639e0a7cb3b 100644
--- a/arch/ia64/kernel/topology.c
+++ b/arch/ia64/kernel/topology.c
@@ -3,9 +3,8 @@
  * License.  See the file "COPYING" in the main directory of this archive
  * for more details.
  *
- * This file contains NUMA specific variables and functions which can
- * be split away from DISCONTIGMEM and are used on NUMA machines with
- * contiguous memory.
+ * This file contains NUMA specific variables and functions which are used on
+ * NUMA machines with contiguous memory.
  * 		2002/08/07 Erich Focht <efocht@ess.nec.de>
  * Populate cpu entries in sysfs for non-numa systems as well
  *  	Intel Corporation - Ashok Raj
diff --git a/arch/ia64/mm/numa.c b/arch/ia64/mm/numa.c
index 46b6e5f3a40f..d6579ec3ea32 100644
--- a/arch/ia64/mm/numa.c
+++ b/arch/ia64/mm/numa.c
@@ -3,9 +3,8 @@
  * License.  See the file "COPYING" in the main directory of this archive
  * for more details.
  *
- * This file contains NUMA specific variables and functions which can
- * be split away from DISCONTIGMEM and are used on NUMA machines with
- * contiguous memory.
+ * This file contains NUMA specific variables and functions which are used on
+ * NUMA machines with contiguous memory.
  * 
  *                         2002/08/07 Erich Focht <efocht@ess.nec.de>
  */
diff --git a/arch/mips/include/asm/mmzone.h b/arch/mips/include/asm/mmzone.h
index b826b8473e95..7649ab45e80c 100644
--- a/arch/mips/include/asm/mmzone.h
+++ b/arch/mips/include/asm/mmzone.h
@@ -20,10 +20,4 @@
 #define nid_to_addrbase(nid) 0
 #endif
 
-#ifdef CONFIG_DISCONTIGMEM
-
-#define pfn_to_nid(pfn)		pa_to_nid((pfn) << PAGE_SHIFT)
-
-#endif /* CONFIG_DISCONTIGMEM */
-
 #endif /* _ASM_MMZONE_H_ */
diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index c36358758969..97f6ca341448 100644
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -454,9 +454,6 @@ void __init mem_init(void)
 	BUILD_BUG_ON(IS_ENABLED(CONFIG_32BIT) && (_PFN_SHIFT > PAGE_SHIFT));
 
 #ifdef CONFIG_HIGHMEM
-#ifdef CONFIG_DISCONTIGMEM
-#error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
-#endif
 	max_mapnr = highend_pfn ? highend_pfn : max_low_pfn;
 #else
 	max_mapnr = max_low_pfn;
diff --git a/arch/nds32/include/asm/memory.h b/arch/nds32/include/asm/memory.h
index 940d32842793..62faafbc28e4 100644
--- a/arch/nds32/include/asm/memory.h
+++ b/arch/nds32/include/asm/memory.h
@@ -76,18 +76,12 @@
  *  virt_to_page(k)	convert a _valid_ virtual address to struct page *
  *  virt_addr_valid(k)	indicates whether a virtual address is valid
  */
-#ifndef CONFIG_DISCONTIGMEM
-
 #define ARCH_PFN_OFFSET		PHYS_PFN_OFFSET
 #define pfn_valid(pfn)		((pfn) >= PHYS_PFN_OFFSET && (pfn) < (PHYS_PFN_OFFSET + max_mapnr))
 
 #define virt_to_page(kaddr)	(pfn_to_page(__pa(kaddr) >> PAGE_SHIFT))
 #define virt_addr_valid(kaddr)	((unsigned long)(kaddr) >= PAGE_OFFSET && (unsigned long)(kaddr) < (unsigned long)high_memory)
 
-#else /* CONFIG_DISCONTIGMEM */
-#error CONFIG_DISCONTIGMEM is not supported yet.
-#endif /* !CONFIG_DISCONTIGMEM */
-
 #define page_to_phys(page)	(page_to_pfn(page) << PAGE_SHIFT)
 
 #endif
diff --git a/arch/xtensa/include/asm/page.h b/arch/xtensa/include/asm/page.h
index 37ce25ef92d6..493eb7083b1a 100644
--- a/arch/xtensa/include/asm/page.h
+++ b/arch/xtensa/include/asm/page.h
@@ -192,10 +192,6 @@ static inline unsigned long ___pa(unsigned long va)
 #define pfn_valid(pfn) \
 	((pfn) >= ARCH_PFN_OFFSET && ((pfn) - ARCH_PFN_OFFSET) < max_mapnr)
 
-#ifdef CONFIG_DISCONTIGMEM
-# error CONFIG_DISCONTIGMEM not supported
-#endif
-
 #define virt_to_page(kaddr)	pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
 #define page_to_virt(page)	__va(page_to_pfn(page) << PAGE_SHIFT)
 #define virt_addr_valid(kaddr)	pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 11da8af06704..dbe1f5fc901d 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -494,8 +494,8 @@ static inline int gfp_zonelist(gfp_t flags)
  * There are two zonelists per node, one for all zones with memory and
  * one containing just zones from the node the zonelist belongs to.
  *
- * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
- * optimized to &contig_page_data at compile-time.
+ * For the case of non-NUMA systems the NODE_DATA() gets optimized to
+ * &contig_page_data at compile-time.
  */
 static inline struct zonelist *node_zonelist(int nid, gfp_t flags)
 {
-- 
2.28.0

[PATCH v2 7/9] docs: remove description of DISCONTIGMEM

[Mike Rapoport]

From: Mike Rapoport <rppt@linux.ibm.com>

Remove description of DISCONTIGMEM from the "Memory Models" document and
update VM sysctl description so that it won't mention DISCONIGMEM.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
---
 Documentation/admin-guide/sysctl/vm.rst | 12 +++----
 Documentation/vm/memory-model.rst       | 45 ++-----------------------
 2 files changed, 8 insertions(+), 49 deletions(-)

diff --git a/Documentation/admin-guide/sysctl/vm.rst b/Documentation/admin-guide/sysctl/vm.rst
index 586cd4b86428..ddbd71d592e0 100644
--- a/Documentation/admin-guide/sysctl/vm.rst
+++ b/Documentation/admin-guide/sysctl/vm.rst
@@ -936,12 +936,12 @@ allocations, THP and hugetlbfs pages.
 
 To make it sensible with respect to the watermark_scale_factor
 parameter, the unit is in fractions of 10,000. The default value of
-15,000 on !DISCONTIGMEM configurations means that up to 150% of the high
-watermark will be reclaimed in the event of a pageblock being mixed due
-to fragmentation. The level of reclaim is determined by the number of
-fragmentation events that occurred in the recent past. If this value is
-smaller than a pageblock then a pageblocks worth of pages will be reclaimed
-(e.g.  2MB on 64-bit x86). A boost factor of 0 will disable the feature.
+15,000 means that up to 150% of the high watermark will be reclaimed in the
+event of a pageblock being mixed due to fragmentation. The level of reclaim
+is determined by the number of fragmentation events that occurred in the
+recent past. If this value is smaller than a pageblock then a pageblocks
+worth of pages will be reclaimed (e.g.  2MB on 64-bit x86). A boost factor
+of 0 will disable the feature.
 
 
 watermark_scale_factor
diff --git a/Documentation/vm/memory-model.rst b/Documentation/vm/memory-model.rst
index ce398a7dc6cd..30e8fbed6914 100644
--- a/Documentation/vm/memory-model.rst
+++ b/Documentation/vm/memory-model.rst
@@ -14,15 +14,11 @@ for the CPU. Then there could be several contiguous ranges at
 completely distinct addresses. And, don't forget about NUMA, where
 different memory banks are attached to different CPUs.
 
-Linux abstracts this diversity using one of the three memory models:
-FLATMEM, DISCONTIGMEM and SPARSEMEM. Each architecture defines what
+Linux abstracts this diversity using one of the two memory models:
+FLATMEM and SPARSEMEM. Each architecture defines what
 memory models it supports, what the default memory model is and
 whether it is possible to manually override that default.
 
-.. note::
-   At time of this writing, DISCONTIGMEM is considered deprecated,
-   although it is still in use by several architectures.
-
 All the memory models track the status of physical page frames using
 struct page arranged in one or more arrays.
 
@@ -63,43 +59,6 @@ straightforward: `PFN - ARCH_PFN_OFFSET` is an index to the
 The `ARCH_PFN_OFFSET` defines the first page frame number for
 systems with physical memory starting at address different from 0.
 
-DISCONTIGMEM
-============
-
-The DISCONTIGMEM model treats the physical memory as a collection of
-`nodes` similarly to how Linux NUMA support does. For each node Linux
-constructs an independent memory management subsystem represented by
-`struct pglist_data` (or `pg_data_t` for short). Among other
-things, `pg_data_t` holds the `node_mem_map` array that maps
-physical pages belonging to that node. The `node_start_pfn` field of
-`pg_data_t` is the number of the first page frame belonging to that
-node.
-
-The architecture setup code should call :c:func:`free_area_init_node` for
-each node in the system to initialize the `pg_data_t` object and its
-`node_mem_map`.
-
-Every `node_mem_map` behaves exactly as FLATMEM's `mem_map` -
-every physical page frame in a node has a `struct page` entry in the
-`node_mem_map` array. When DISCONTIGMEM is enabled, a portion of the
-`flags` field of the `struct page` encodes the node number of the
-node hosting that page.
-
-The conversion between a PFN and the `struct page` in the
-DISCONTIGMEM model became slightly more complex as it has to determine
-which node hosts the physical page and which `pg_data_t` object
-holds the `struct page`.
-
-Architectures that support DISCONTIGMEM provide :c:func:`pfn_to_nid`
-to convert PFN to the node number. The opposite conversion helper
-:c:func:`page_to_nid` is generic as it uses the node number encoded in
-page->flags.
-
-Once the node number is known, the PFN can be used to index
-appropriate `node_mem_map` array to access the `struct page` and
-the offset of the `struct page` from the `node_mem_map` plus
-`node_start_pfn` is the PFN of that page.
-
 SPARSEMEM
 =========
 
-- 
2.28.0

[PATCH v2 8/9] mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA

[Mike Rapoport]

From: Mike Rapoport <rppt@linux.ibm.com>

After removal of DISCINTIGMEM the NEED_MULTIPLE_NODES and NUMA
configuration options are equivalent.

Drop CONFIG_NEED_MULTIPLE_NODES and use CONFIG_NUMA instead.

Done with

	$ sed -i 's/CONFIG_NEED_MULTIPLE_NODES/CONFIG_NUMA/' \
		$(git grep -wl CONFIG_NEED_MULTIPLE_NODES)
	$ sed -i 's/NEED_MULTIPLE_NODES/NUMA/' \
		$(git grep -wl NEED_MULTIPLE_NODES)

with manual tweaks afterwards.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
---
 arch/arm64/Kconfig                |  2 +-
 arch/ia64/Kconfig                 |  2 +-
 arch/mips/Kconfig                 |  2 +-
 arch/mips/include/asm/mmzone.h    |  2 +-
 arch/mips/include/asm/page.h      |  2 +-
 arch/mips/mm/init.c               |  4 ++--
 arch/powerpc/Kconfig              |  2 +-
 arch/powerpc/include/asm/mmzone.h |  4 ++--
 arch/powerpc/kernel/setup_64.c    |  2 +-
 arch/powerpc/kernel/smp.c         |  2 +-
 arch/powerpc/kexec/core.c         |  4 ++--
 arch/powerpc/mm/Makefile          |  2 +-
 arch/powerpc/mm/mem.c             |  4 ++--
 arch/riscv/Kconfig                |  2 +-
 arch/s390/Kconfig                 |  2 +-
 arch/sh/include/asm/mmzone.h      |  4 ++--
 arch/sh/kernel/topology.c         |  2 +-
 arch/sh/mm/Kconfig                |  2 +-
 arch/sh/mm/init.c                 |  2 +-
 arch/sparc/Kconfig                |  2 +-
 arch/sparc/include/asm/mmzone.h   |  4 ++--
 arch/sparc/kernel/smp_64.c        |  2 +-
 arch/sparc/mm/init_64.c           | 12 ++++++------
 arch/x86/Kconfig                  |  2 +-
 arch/x86/kernel/setup_percpu.c    |  6 +++---
 arch/x86/mm/init_32.c             |  4 ++--
 include/asm-generic/topology.h    |  2 +-
 include/linux/memblock.h          |  6 +++---
 include/linux/mm.h                |  4 ++--
 include/linux/mmzone.h            |  8 ++++----
 kernel/crash_core.c               |  2 +-
 mm/Kconfig                        |  9 ---------
 mm/memblock.c                     |  8 ++++----
 mm/page_alloc.c                   |  6 +++---
 34 files changed, 58 insertions(+), 67 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 9f1d8566bbf9..d01a1545ab8f 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1035,7 +1035,7 @@ config NODES_SHIFT
 	int "Maximum NUMA Nodes (as a power of 2)"
 	range 1 10
 	default "4"
-	depends on NEED_MULTIPLE_NODES
+	depends on NUMA
 	help
 	  Specify the maximum number of NUMA Nodes available on the target
 	  system.  Increases memory reserved to accommodate various tables.
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 279252e3e0f7..da22a35e6f03 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -302,7 +302,7 @@ config NODES_SHIFT
 	int "Max num nodes shift(3-10)"
 	range 3 10
 	default "10"
-	depends on NEED_MULTIPLE_NODES
+	depends on NUMA
 	help
 	  This option specifies the maximum number of nodes in your SSI system.
 	  MAX_NUMNODES will be 2^(This value).
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index ed51970c08e7..4704a16c2e44 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2867,7 +2867,7 @@ config RANDOMIZE_BASE_MAX_OFFSET
 config NODES_SHIFT
 	int
 	default "6"
-	depends on NEED_MULTIPLE_NODES
+	depends on NUMA
 
 config HW_PERF_EVENTS
 	bool "Enable hardware performance counter support for perf events"
diff --git a/arch/mips/include/asm/mmzone.h b/arch/mips/include/asm/mmzone.h
index 7649ab45e80c..602a21aee9d4 100644
--- a/arch/mips/include/asm/mmzone.h
+++ b/arch/mips/include/asm/mmzone.h
@@ -8,7 +8,7 @@
 
 #include <asm/page.h>
 
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 # include <mmzone.h>
 #endif
 
diff --git a/arch/mips/include/asm/page.h b/arch/mips/include/asm/page.h
index 195ff4e9771f..96bc798c1ec1 100644
--- a/arch/mips/include/asm/page.h
+++ b/arch/mips/include/asm/page.h
@@ -239,7 +239,7 @@ static inline int pfn_valid(unsigned long pfn)
 
 /* pfn_valid is defined in linux/mmzone.h */
 
-#elif defined(CONFIG_NEED_MULTIPLE_NODES)
+#elif defined(CONFIG_NUMA)
 
 #define pfn_valid(pfn)							\
 ({									\
diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index 97f6ca341448..19347dc6bbf8 100644
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -394,7 +394,7 @@ void maar_init(void)
 	}
 }
 
-#ifndef CONFIG_NEED_MULTIPLE_NODES
+#ifndef CONFIG_NUMA
 void __init paging_init(void)
 {
 	unsigned long max_zone_pfns[MAX_NR_ZONES];
@@ -473,7 +473,7 @@ void __init mem_init(void)
 				0x80000000 - 4, KCORE_TEXT);
 #endif
 }
-#endif /* !CONFIG_NEED_MULTIPLE_NODES */
+#endif /* !CONFIG_NUMA */
 
 void free_init_pages(const char *what, unsigned long begin, unsigned long end)
 {
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 088dd2afcfe4..14b132cf95e2 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -671,7 +671,7 @@ config NODES_SHIFT
 	int
 	default "8" if PPC64
 	default "4"
-	depends on NEED_MULTIPLE_NODES
+	depends on NUMA
 
 config USE_PERCPU_NUMA_NODE_ID
 	def_bool y
diff --git a/arch/powerpc/include/asm/mmzone.h b/arch/powerpc/include/asm/mmzone.h
index 6cda76b57c5d..4c6c6dbd182f 100644
--- a/arch/powerpc/include/asm/mmzone.h
+++ b/arch/powerpc/include/asm/mmzone.h
@@ -18,7 +18,7 @@
  *    flags field of the struct page
  */
 
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 
 extern struct pglist_data *node_data[];
 /*
@@ -41,7 +41,7 @@ u64 memory_hotplug_max(void);
 
 #else
 #define memory_hotplug_max() memblock_end_of_DRAM()
-#endif /* CONFIG_NEED_MULTIPLE_NODES */
+#endif /* CONFIG_NUMA */
 #ifdef CONFIG_FA_DUMP
 #define __HAVE_ARCH_RESERVED_KERNEL_PAGES
 #endif
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index e42b85e4f1aa..a35fbf4d0bce 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -788,7 +788,7 @@ static void * __init pcpu_alloc_bootmem(unsigned int cpu, size_t size,
 					size_t align)
 {
 	const unsigned long goal = __pa(MAX_DMA_ADDRESS);
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 	int node = early_cpu_to_node(cpu);
 	void *ptr;
 
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 2e05c783440a..a5209ea3859e 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -1047,7 +1047,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
 			zalloc_cpumask_var_node(&per_cpu(cpu_coregroup_map, cpu),
 						GFP_KERNEL, cpu_to_node(cpu));
 
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 		/*
 		 * numa_node_id() works after this.
 		 */
diff --git a/arch/powerpc/kexec/core.c b/arch/powerpc/kexec/core.c
index 56da5eb2b923..48525e8b5730 100644
--- a/arch/powerpc/kexec/core.c
+++ b/arch/powerpc/kexec/core.c
@@ -68,11 +68,11 @@ void machine_kexec_cleanup(struct kimage *image)
 void arch_crash_save_vmcoreinfo(void)
 {
 
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 	VMCOREINFO_SYMBOL(node_data);
 	VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
 #endif
-#ifndef CONFIG_NEED_MULTIPLE_NODES
+#ifndef CONFIG_NUMA
 	VMCOREINFO_SYMBOL(contig_page_data);
 #endif
 #if defined(CONFIG_PPC64) && defined(CONFIG_SPARSEMEM_VMEMMAP)
diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile
index c3df3a8501d4..2ffcf540f08b 100644
--- a/arch/powerpc/mm/Makefile
+++ b/arch/powerpc/mm/Makefile
@@ -13,7 +13,7 @@ obj-y				:= fault.o mem.o pgtable.o mmap.o maccess.o \
 obj-$(CONFIG_PPC_MMU_NOHASH)	+= nohash/
 obj-$(CONFIG_PPC_BOOK3S_32)	+= book3s32/
 obj-$(CONFIG_PPC_BOOK3S_64)	+= book3s64/
-obj-$(CONFIG_NEED_MULTIPLE_NODES) += numa.o
+obj-$(CONFIG_NUMA) += numa.o
 obj-$(CONFIG_PPC_MM_SLICES)	+= slice.o
 obj-$(CONFIG_HUGETLB_PAGE)	+= hugetlbpage.o
 obj-$(CONFIG_NOT_COHERENT_CACHE) += dma-noncoherent.o
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 043bbeaf407c..7a266991315f 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -126,7 +126,7 @@ void __ref arch_remove_memory(int nid, u64 start, u64 size,
 }
 #endif
 
-#ifndef CONFIG_NEED_MULTIPLE_NODES
+#ifndef CONFIG_NUMA
 void __init mem_topology_setup(void)
 {
 	max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
@@ -161,7 +161,7 @@ static int __init mark_nonram_nosave(void)
 
 	return 0;
 }
-#else /* CONFIG_NEED_MULTIPLE_NODES */
+#else /* CONFIG_NUMA */
 static int __init mark_nonram_nosave(void)
 {
 	return 0;
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index a8ad8eb76120..e985dbf9ff27 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -331,7 +331,7 @@ config NODES_SHIFT
 	int "Maximum NUMA Nodes (as a power of 2)"
 	range 1 10
 	default "2"
-	depends on NEED_MULTIPLE_NODES
+	depends on NUMA
 	help
 	  Specify the maximum number of NUMA Nodes available on the target
 	  system.  Increases memory reserved to accommodate various tables.
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index b4c7c34069f8..707afbcd81c2 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -475,7 +475,7 @@ config NUMA
 
 config NODES_SHIFT
 	int
-	depends on NEED_MULTIPLE_NODES
+	depends on NUMA
 	default "1"
 
 config SCHED_SMT
diff --git a/arch/sh/include/asm/mmzone.h b/arch/sh/include/asm/mmzone.h
index 6552a088dc97..7b8dead2723d 100644
--- a/arch/sh/include/asm/mmzone.h
+++ b/arch/sh/include/asm/mmzone.h
@@ -2,7 +2,7 @@
 #ifndef __ASM_SH_MMZONE_H
 #define __ASM_SH_MMZONE_H
 
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 #include <linux/numa.h>
 
 extern struct pglist_data *node_data[];
@@ -31,7 +31,7 @@ static inline void
 setup_bootmem_node(int nid, unsigned long start, unsigned long end)
 {
 }
-#endif /* CONFIG_NEED_MULTIPLE_NODES */
+#endif /* CONFIG_NUMA */
 
 /* Platform specific mem init */
 void __init plat_mem_setup(void);
diff --git a/arch/sh/kernel/topology.c b/arch/sh/kernel/topology.c
index 7a989eed3b18..76af6db9daa2 100644
--- a/arch/sh/kernel/topology.c
+++ b/arch/sh/kernel/topology.c
@@ -46,7 +46,7 @@ static int __init topology_init(void)
 {
 	int i, ret;
 
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 	for_each_online_node(i)
 		register_one_node(i);
 #endif
diff --git a/arch/sh/mm/Kconfig b/arch/sh/mm/Kconfig
index d551a9cac41e..ba569cfb4368 100644
--- a/arch/sh/mm/Kconfig
+++ b/arch/sh/mm/Kconfig
@@ -120,7 +120,7 @@ config NODES_SHIFT
 	int
 	default "3" if CPU_SUBTYPE_SHX3
 	default "1"
-	depends on NEED_MULTIPLE_NODES
+	depends on NUMA
 
 config ARCH_FLATMEM_ENABLE
 	def_bool y
diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
index 168d7d4dd735..ce26c7f8950a 100644
--- a/arch/sh/mm/init.c
+++ b/arch/sh/mm/init.c
@@ -211,7 +211,7 @@ void __init allocate_pgdat(unsigned int nid)
 
 	get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
 
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 	NODE_DATA(nid) = memblock_alloc_try_nid(
 				sizeof(struct pglist_data),
 				SMP_CACHE_BYTES, MEMBLOCK_LOW_LIMIT,
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 164a5254c91c..c72f52c704cd 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -265,7 +265,7 @@ config NODES_SHIFT
 	int "Maximum NUMA Nodes (as a power of 2)"
 	range 4 5 if SPARC64
 	default "5"
-	depends on NEED_MULTIPLE_NODES
+	depends on NUMA
 	help
 	  Specify the maximum number of NUMA Nodes available on the target
 	  system.  Increases memory reserved to accommodate various tables.
diff --git a/arch/sparc/include/asm/mmzone.h b/arch/sparc/include/asm/mmzone.h
index 6543fb97a849..a236d8aa893a 100644
--- a/arch/sparc/include/asm/mmzone.h
+++ b/arch/sparc/include/asm/mmzone.h
@@ -2,7 +2,7 @@
 #ifndef _SPARC64_MMZONE_H
 #define _SPARC64_MMZONE_H
 
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 
 #include <linux/cpumask.h>
 
@@ -13,6 +13,6 @@ extern struct pglist_data *node_data[];
 extern int numa_cpu_lookup_table[];
 extern cpumask_t numa_cpumask_lookup_table[];
 
-#endif /* CONFIG_NEED_MULTIPLE_NODES */
+#endif /* CONFIG_NUMA */
 
 #endif /* _SPARC64_MMZONE_H */
diff --git a/arch/sparc/kernel/smp_64.c b/arch/sparc/kernel/smp_64.c
index e38d8bf454e8..c89a5971fb0d 100644
--- a/arch/sparc/kernel/smp_64.c
+++ b/arch/sparc/kernel/smp_64.c
@@ -1546,7 +1546,7 @@ static void * __init pcpu_alloc_bootmem(unsigned int cpu, size_t size,
 					size_t align)
 {
 	const unsigned long goal = __pa(MAX_DMA_ADDRESS);
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 	int node = cpu_to_node(cpu);
 	void *ptr;
 
diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index e454f179cf5d..06e938d03f3b 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -903,7 +903,7 @@ struct node_mem_mask {
 static struct node_mem_mask node_masks[MAX_NUMNODES];
 static int num_node_masks;
 
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 
 struct mdesc_mlgroup {
 	u64	node;
@@ -1059,7 +1059,7 @@ static void __init allocate_node_data(int nid)
 {
 	struct pglist_data *p;
 	unsigned long start_pfn, end_pfn;
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 
 	NODE_DATA(nid) = memblock_alloc_node(sizeof(struct pglist_data),
 					     SMP_CACHE_BYTES, nid);
@@ -1080,7 +1080,7 @@ static void __init allocate_node_data(int nid)
 
 static void init_node_masks_nonnuma(void)
 {
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 	int i;
 #endif
 
@@ -1090,7 +1090,7 @@ static void init_node_masks_nonnuma(void)
 	node_masks[0].match = 0;
 	num_node_masks = 1;
 
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 	for (i = 0; i < NR_CPUS; i++)
 		numa_cpu_lookup_table[i] = 0;
 
@@ -1098,7 +1098,7 @@ static void init_node_masks_nonnuma(void)
 #endif
 }
 
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 struct pglist_data *node_data[MAX_NUMNODES];
 
 EXPORT_SYMBOL(numa_cpu_lookup_table);
@@ -2487,7 +2487,7 @@ int page_in_phys_avail(unsigned long paddr)
 
 static void __init register_page_bootmem_info(void)
 {
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 	int i;
 
 	for_each_online_node(i)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 0045e1b44190..5d523ff70fe7 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1597,7 +1597,7 @@ config NODES_SHIFT
 	default "10" if MAXSMP
 	default "6" if X86_64
 	default "3"
-	depends on NEED_MULTIPLE_NODES
+	depends on NUMA
 	help
 	  Specify the maximum number of NUMA Nodes available on the target
 	  system.  Increases memory reserved to accommodate various tables.
diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c
index 0941d2f44f2a..78a32b956e81 100644
--- a/arch/x86/kernel/setup_percpu.c
+++ b/arch/x86/kernel/setup_percpu.c
@@ -66,7 +66,7 @@ EXPORT_SYMBOL(__per_cpu_offset);
  */
 static bool __init pcpu_need_numa(void)
 {
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 	pg_data_t *last = NULL;
 	unsigned int cpu;
 
@@ -101,7 +101,7 @@ static void * __init pcpu_alloc_bootmem(unsigned int cpu, unsigned long size,
 					unsigned long align)
 {
 	const unsigned long goal = __pa(MAX_DMA_ADDRESS);
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 	int node = early_cpu_to_node(cpu);
 	void *ptr;
 
@@ -140,7 +140,7 @@ static void __init pcpu_fc_free(void *ptr, size_t size)
 
 static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
 {
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 	if (early_cpu_to_node(from) == early_cpu_to_node(to))
 		return LOCAL_DISTANCE;
 	else
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 21ffb03f6c72..74b78840182d 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -651,7 +651,7 @@ void __init find_low_pfn_range(void)
 		highmem_pfn_init();
 }
 
-#ifndef CONFIG_NEED_MULTIPLE_NODES
+#ifndef CONFIG_NUMA
 void __init initmem_init(void)
 {
 #ifdef CONFIG_HIGHMEM
@@ -677,7 +677,7 @@ void __init initmem_init(void)
 
 	setup_bootmem_allocator();
 }
-#endif /* !CONFIG_NEED_MULTIPLE_NODES */
+#endif /* !CONFIG_NUMA */
 
 void __init setup_bootmem_allocator(void)
 {
diff --git a/include/asm-generic/topology.h b/include/asm-generic/topology.h
index 5aa8705df87e..4dbe715be65b 100644
--- a/include/asm-generic/topology.h
+++ b/include/asm-generic/topology.h
@@ -45,7 +45,7 @@
 #endif
 
 #ifndef cpumask_of_node
-  #ifdef CONFIG_NEED_MULTIPLE_NODES
+  #ifdef CONFIG_NUMA
     #define cpumask_of_node(node)	((node) == 0 ? cpu_online_mask : cpu_none_mask)
   #else
     #define cpumask_of_node(node)	((void)(node), cpu_online_mask)
diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 5984fff3f175..552309342c38 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -50,7 +50,7 @@ struct memblock_region {
 	phys_addr_t base;
 	phys_addr_t size;
 	enum memblock_flags flags;
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 	int nid;
 #endif
 };
@@ -347,7 +347,7 @@ int __init deferred_page_init_max_threads(const struct cpumask *node_cpumask);
 int memblock_set_node(phys_addr_t base, phys_addr_t size,
 		      struct memblock_type *type, int nid);
 
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 static inline void memblock_set_region_node(struct memblock_region *r, int nid)
 {
 	r->nid = nid;
@@ -366,7 +366,7 @@ static inline int memblock_get_region_node(const struct memblock_region *r)
 {
 	return 0;
 }
-#endif /* CONFIG_NEED_MULTIPLE_NODES */
+#endif /* CONFIG_NUMA */
 
 /* Flags for memblock allocation APIs */
 #define MEMBLOCK_ALLOC_ANYWHERE	(~(phys_addr_t)0)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index c274f75efcf9..cf66f0ea7956 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -46,7 +46,7 @@ extern int sysctl_page_lock_unfairness;
 
 void init_mm_internals(void);
 
-#ifndef CONFIG_NEED_MULTIPLE_NODES	/* Don't use mapnrs, do it properly */
+#ifndef CONFIG_NUMA		/* Don't use mapnrs, do it properly */
 extern unsigned long max_mapnr;
 
 static inline void set_max_mapnr(unsigned long limit)
@@ -2457,7 +2457,7 @@ extern void get_pfn_range_for_nid(unsigned int nid,
 			unsigned long *start_pfn, unsigned long *end_pfn);
 extern unsigned long find_min_pfn_with_active_regions(void);
 
-#ifndef CONFIG_NEED_MULTIPLE_NODES
+#ifndef CONFIG_NUMA
 static inline int early_pfn_to_nid(unsigned long pfn)
 {
 	return 0;
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 700032e99419..acdc51c7b259 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -987,7 +987,7 @@ extern int movable_zone;
 #ifdef CONFIG_HIGHMEM
 static inline int zone_movable_is_highmem(void)
 {
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 	return movable_zone == ZONE_HIGHMEM;
 #else
 	return (ZONE_MOVABLE - 1) == ZONE_HIGHMEM;
@@ -1043,17 +1043,17 @@ extern int percpu_pagelist_fraction;
 extern char numa_zonelist_order[];
 #define NUMA_ZONELIST_ORDER_LEN	16
 
-#ifndef CONFIG_NEED_MULTIPLE_NODES
+#ifndef CONFIG_NUMA
 
 extern struct pglist_data contig_page_data;
 #define NODE_DATA(nid)		(&contig_page_data)
 #define NODE_MEM_MAP(nid)	mem_map
 
-#else /* CONFIG_NEED_MULTIPLE_NODES */
+#else /* CONFIG_NUMA */
 
 #include <asm/mmzone.h>
 
-#endif /* !CONFIG_NEED_MULTIPLE_NODES */
+#endif /* !CONFIG_NUMA */
 
 extern struct pglist_data *first_online_pgdat(void);
 extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat);
diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 825284baaf46..53eb8bc6026d 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -455,7 +455,7 @@ static int __init crash_save_vmcoreinfo_init(void)
 	VMCOREINFO_SYMBOL(_stext);
 	VMCOREINFO_SYMBOL(vmap_area_list);
 
-#ifndef CONFIG_NEED_MULTIPLE_NODES
+#ifndef CONFIG_NUMA
 	VMCOREINFO_SYMBOL(mem_map);
 	VMCOREINFO_SYMBOL(contig_page_data);
 #endif
diff --git a/mm/Kconfig b/mm/Kconfig
index 218b96ccc84a..bffe4bd859f3 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -59,15 +59,6 @@ config FLAT_NODE_MEM_MAP
 	def_bool y
 	depends on !SPARSEMEM
 
-#
-# Both the NUMA code and DISCONTIGMEM use arrays of pg_data_t's
-# to represent different areas of memory.  This variable allows
-# those dependencies to exist individually.
-#
-config NEED_MULTIPLE_NODES
-	def_bool y
-	depends on NUMA
-
 #
 # SPARSEMEM_EXTREME (which is the default) does some bootmem
 # allocations when sparse_init() is called.  If this cannot
diff --git a/mm/memblock.c b/mm/memblock.c
index afaefa8fc6ab..123feef5259d 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -92,7 +92,7 @@
  * system initialization completes.
  */
 
-#ifndef CONFIG_NEED_MULTIPLE_NODES
+#ifndef CONFIG_NUMA
 struct pglist_data __refdata contig_page_data;
 EXPORT_SYMBOL(contig_page_data);
 #endif
@@ -607,7 +607,7 @@ static int __init_memblock memblock_add_range(struct memblock_type *type,
 		 * area, insert that portion.
 		 */
 		if (rbase > base) {
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 			WARN_ON(nid != memblock_get_region_node(rgn));
 #endif
 			WARN_ON(flags != rgn->flags);
@@ -1205,7 +1205,7 @@ void __init_memblock __next_mem_pfn_range(int *idx, int nid,
 int __init_memblock memblock_set_node(phys_addr_t base, phys_addr_t size,
 				      struct memblock_type *type, int nid)
 {
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 	int start_rgn, end_rgn;
 	int i, ret;
 
@@ -1849,7 +1849,7 @@ static void __init_memblock memblock_dump(struct memblock_type *type)
 		size = rgn->size;
 		end = base + size - 1;
 		flags = rgn->flags;
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 		if (memblock_get_region_node(rgn) != MAX_NUMNODES)
 			snprintf(nid_buf, sizeof(nid_buf), " on node %d",
 				 memblock_get_region_node(rgn));
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 6fc22482eaa8..8f08135d3eb4 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1596,7 +1596,7 @@ void __free_pages_core(struct page *page, unsigned int order)
 	__free_pages_ok(page, order, FPI_TO_TAIL | FPI_SKIP_KASAN_POISON);
 }
 
-#ifdef CONFIG_NEED_MULTIPLE_NODES
+#ifdef CONFIG_NUMA
 
 /*
  * During memory init memblocks map pfns to nids. The search is expensive and
@@ -1646,7 +1646,7 @@ int __meminit early_pfn_to_nid(unsigned long pfn)
 
 	return nid;
 }
-#endif /* CONFIG_NEED_MULTIPLE_NODES */
+#endif /* CONFIG_NUMA */
 
 void __init memblock_free_pages(struct page *page, unsigned long pfn,
 							unsigned int order)
@@ -7276,7 +7276,7 @@ static void __ref alloc_node_mem_map(struct pglist_data *pgdat)
 	pr_debug("%s: node %d, pgdat %08lx, node_mem_map %08lx\n",
 				__func__, pgdat->node_id, (unsigned long)pgdat,
 				(unsigned long)pgdat->node_mem_map);
-#ifndef CONFIG_NEED_MULTIPLE_NODES
+#ifndef CONFIG_NUMA
 	/*
 	 * With no DISCONTIG, the global mem_map is just set as node 0's
 	 */
-- 
2.28.0

Re: [PATCH v2 8/9] mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA

[Geert Uytterhoeven]

Hi Mike,

On Fri, Jun 4, 2021 at 8:50 AM Mike Rapoport <rppt@kernel.org> wrote:
> From: Mike Rapoport <rppt@linux.ibm.com>
>
> After removal of DISCINTIGMEM the NEED_MULTIPLE_NODES and NUMA
> configuration options are equivalent.
>
> Drop CONFIG_NEED_MULTIPLE_NODES and use CONFIG_NUMA instead.
>
> Done with
>
>         $ sed -i 's/CONFIG_NEED_MULTIPLE_NODES/CONFIG_NUMA/' \
>                 $(git grep -wl CONFIG_NEED_MULTIPLE_NODES)
>         $ sed -i 's/NEED_MULTIPLE_NODES/NUMA/' \
>                 $(git grep -wl NEED_MULTIPLE_NODES)
>
> with manual tweaks afterwards.
>
> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>

Thanks for your patch!

As you dropped the following hunk from v2 of PATCH 5/9, there's now
one reference left of CONFIG_NEED_MULTIPLE_NODES
(plus the discontigmem comment):

-diff --git a/mm/memory.c b/mm/memory.c
-index f3ffab9b9e39157b..fd0ebb63be3304f5 100644
---- a/mm/memory.c
-+++ b/mm/memory.c
-@@ -90,8 +90,7 @@
- #warning Unfortunate NUMA and NUMA Balancing config, growing
page-frame for last_cpupid.
- #endif
-
--#ifndef CONFIG_NEED_MULTIPLE_NODES
--/* use the per-pgdat data instead for discontigmem - mbligh */
-+#ifdef CONFIG_FLATMEM
- unsigned long max_mapnr;
- EXPORT_SYMBOL(max_mapnr);
-

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH v2 8/9] mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA

[Mike Rapoport]

Hi,

On Mon, Jun 07, 2021 at 10:53:08AM +0200, Geert Uytterhoeven wrote:
> Hi Mike,
> 
> On Fri, Jun 4, 2021 at 8:50 AM Mike Rapoport <rppt@kernel.org> wrote:
> > From: Mike Rapoport <rppt@linux.ibm.com>
> >
> > After removal of DISCINTIGMEM the NEED_MULTIPLE_NODES and NUMA
> > configuration options are equivalent.
> >
> > Drop CONFIG_NEED_MULTIPLE_NODES and use CONFIG_NUMA instead.
> >
> > Done with
> >
> >         $ sed -i 's/CONFIG_NEED_MULTIPLE_NODES/CONFIG_NUMA/' \
> >                 $(git grep -wl CONFIG_NEED_MULTIPLE_NODES)
> >         $ sed -i 's/NEED_MULTIPLE_NODES/NUMA/' \
> >                 $(git grep -wl NEED_MULTIPLE_NODES)
> >
> > with manual tweaks afterwards.
> >
> > Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
> 
> Thanks for your patch!
> 
> As you dropped the following hunk from v2 of PATCH 5/9, there's now
> one reference left of CONFIG_NEED_MULTIPLE_NODES
> (plus the discontigmem comment):

Aargh, indeed. Thanks for catching this.

And I wondered why you suggested to fix spelling in cover letter for v3 :)
 
> -diff --git a/mm/memory.c b/mm/memory.c
> -index f3ffab9b9e39157b..fd0ebb63be3304f5 100644
> ---- a/mm/memory.c
> -+++ b/mm/memory.c
> -@@ -90,8 +90,7 @@
> - #warning Unfortunate NUMA and NUMA Balancing config, growing
> page-frame for last_cpupid.
> - #endif
> -
> --#ifndef CONFIG_NEED_MULTIPLE_NODES
> --/* use the per-pgdat data instead for discontigmem - mbligh */
> -+#ifdef CONFIG_FLATMEM
> - unsigned long max_mapnr;
> - EXPORT_SYMBOL(max_mapnr);
> -
> 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> -- 
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds

-- 
Sincerely yours,
Mike.

[PATCH v2 9/9] mm: replace CONFIG_FLAT_NODE_MEM_MAP with CONFIG_FLATMEM

[Mike Rapoport]

From: Mike Rapoport <rppt@linux.ibm.com>

After removal of the DISCONTIGMEM memory model the FLAT_NODE_MEM_MAP
configuration option is equivalent to FLATMEM.

Drop CONFIG_FLAT_NODE_MEM_MAP and use CONFIG_FLATMEM instead.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
---
 include/linux/mmzone.h | 4 ++--
 kernel/crash_core.c    | 2 +-
 mm/Kconfig             | 4 ----
 mm/page_alloc.c        | 6 +++---
 mm/page_ext.c          | 2 +-
 5 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index acdc51c7b259..1d5cafe5ccc3 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -777,7 +777,7 @@ typedef struct pglist_data {
 	struct zonelist node_zonelists[MAX_ZONELISTS];
 
 	int nr_zones; /* number of populated zones in this node */
-#ifdef CONFIG_FLAT_NODE_MEM_MAP	/* means !SPARSEMEM */
+#ifdef CONFIG_FLATMEM	/* means !SPARSEMEM */
 	struct page *node_mem_map;
 #ifdef CONFIG_PAGE_EXTENSION
 	struct page_ext *node_page_ext;
@@ -867,7 +867,7 @@ typedef struct pglist_data {
 
 #define node_present_pages(nid)	(NODE_DATA(nid)->node_present_pages)
 #define node_spanned_pages(nid)	(NODE_DATA(nid)->node_spanned_pages)
-#ifdef CONFIG_FLAT_NODE_MEM_MAP
+#ifdef CONFIG_FLATMEM
 #define pgdat_page_nr(pgdat, pagenr)	((pgdat)->node_mem_map + (pagenr))
 #else
 #define pgdat_page_nr(pgdat, pagenr)	pfn_to_page((pgdat)->node_start_pfn + (pagenr))
diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 53eb8bc6026d..2b8446ea7105 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -483,7 +483,7 @@ static int __init crash_save_vmcoreinfo_init(void)
 	VMCOREINFO_OFFSET(page, compound_head);
 	VMCOREINFO_OFFSET(pglist_data, node_zones);
 	VMCOREINFO_OFFSET(pglist_data, nr_zones);
-#ifdef CONFIG_FLAT_NODE_MEM_MAP
+#ifdef CONFIG_FLATMEM
 	VMCOREINFO_OFFSET(pglist_data, node_mem_map);
 #endif
 	VMCOREINFO_OFFSET(pglist_data, node_start_pfn);
diff --git a/mm/Kconfig b/mm/Kconfig
index bffe4bd859f3..ded98fb859ab 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -55,10 +55,6 @@ config FLATMEM
 	def_bool y
 	depends on !SPARSEMEM || FLATMEM_MANUAL
 
-config FLAT_NODE_MEM_MAP
-	def_bool y
-	depends on !SPARSEMEM
-
 #
 # SPARSEMEM_EXTREME (which is the default) does some bootmem
 # allocations when sparse_init() is called.  If this cannot
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 8f08135d3eb4..f039736541eb 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6444,7 +6444,7 @@ static void __meminit zone_init_free_lists(struct zone *zone)
 	}
 }
 
-#if !defined(CONFIG_FLAT_NODE_MEM_MAP)
+#if !defined(CONFIG_FLATMEM)
 /*
  * Only struct pages that correspond to ranges defined by memblock.memory
  * are zeroed and initialized by going through __init_single_page() during
@@ -7241,7 +7241,7 @@ static void __init free_area_init_core(struct pglist_data *pgdat)
 	}
 }
 
-#ifdef CONFIG_FLAT_NODE_MEM_MAP
+#ifdef CONFIG_FLATMEM
 static void __ref alloc_node_mem_map(struct pglist_data *pgdat)
 {
 	unsigned long __maybe_unused start = 0;
@@ -7289,7 +7289,7 @@ static void __ref alloc_node_mem_map(struct pglist_data *pgdat)
 }
 #else
 static void __ref alloc_node_mem_map(struct pglist_data *pgdat) { }
-#endif /* CONFIG_FLAT_NODE_MEM_MAP */
+#endif /* CONFIG_FLATMEM */
 
 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
 static inline void pgdat_set_deferred_range(pg_data_t *pgdat)
diff --git a/mm/page_ext.c b/mm/page_ext.c
index df6f74aac8e1..293b2685fc48 100644
--- a/mm/page_ext.c
+++ b/mm/page_ext.c
@@ -191,7 +191,7 @@ void __init page_ext_init_flatmem(void)
 	panic("Out of memory");
 }
 
-#else /* CONFIG_FLAT_NODE_MEM_MAP */
+#else /* CONFIG_FLATMEM */
 
 struct page_ext *lookup_page_ext(const struct page *page)
 {
-- 
2.28.0

Re: [PATCH v2 0/9] Remove DISCINTIGMEM memory model

[Geert Uytterhoeven]

Hi Mike,

You may want to fix the DISCINTIGMEM typo in the subject for v3, unless
you think that makes tracking series versions more complicated ;-)

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH v2 0/9] Remove DISCINTIGMEM memory model

[Arnd Bergmann]

On Fri, Jun 4, 2021 at 8:49 AM Mike Rapoport <rppt@kernel.org> wrote:
>
> From: Mike Rapoport <rppt@linux.ibm.com>
>
> Hi,
>
> SPARSEMEM memory model was supposed to entirely replace DISCONTIGMEM a
> (long) while ago. The last architectures that used DISCONTIGMEM were
> updated to use other memory models in v5.11 and it is about the time to
> entirely remove DISCONTIGMEM from the kernel.
>
> This set removes DISCONTIGMEM from alpha, arc and m68k, simplifies memory
> model selection in mm/Kconfig and replaces usage of redundant
> CONFIG_NEED_MULTIPLE_NODES and CONFIG_FLAT_NODE_MEM_MAP with CONFIG_NUMA
> and CONFIG_FLATMEM respectively.
>
> I've also removed NUMA support on alpha that was BROKEN for more than 15
> years.
>
> There were also minor updates all over arch/ to remove mentions of
> DISCONTIGMEM in comments and #ifdefs.

Hi Mike and Andrew,

It looks like everyone is happy with this version so far. How should we merge it
for linux-next? I'm happy to take it through the asm-generic tree, but linux-mm
would fit at least as well. In case we go for linux-mm, feel free to add

Acked-by: Arnd Bergmann <arnd@arndb.de>

for the whole series.

Re: [PATCH v2 0/9] Remove DISCINTIGMEM memory model

[Mike Rapoport]

Hi Arnd,

On Wed, Jun 09, 2021 at 01:30:39PM +0200, Arnd Bergmann wrote:
> On Fri, Jun 4, 2021 at 8:49 AM Mike Rapoport <rppt@kernel.org> wrote:
> >
> > From: Mike Rapoport <rppt@linux.ibm.com>
> >
> > Hi,
> >
> > SPARSEMEM memory model was supposed to entirely replace DISCONTIGMEM a
> > (long) while ago. The last architectures that used DISCONTIGMEM were
> > updated to use other memory models in v5.11 and it is about the time to
> > entirely remove DISCONTIGMEM from the kernel.
> >
> > This set removes DISCONTIGMEM from alpha, arc and m68k, simplifies memory
> > model selection in mm/Kconfig and replaces usage of redundant
> > CONFIG_NEED_MULTIPLE_NODES and CONFIG_FLAT_NODE_MEM_MAP with CONFIG_NUMA
> > and CONFIG_FLATMEM respectively.
> >
> > I've also removed NUMA support on alpha that was BROKEN for more than 15
> > years.
> >
> > There were also minor updates all over arch/ to remove mentions of
> > DISCONTIGMEM in comments and #ifdefs.
> 
> Hi Mike and Andrew,
> 
> It looks like everyone is happy with this version so far. How should we merge it
> for linux-next? I'm happy to take it through the asm-generic tree, but linux-mm
> would fit at least as well. In case we go for linux-mm, feel free to add

Andrew already took to mmotm.
 
> Acked-by: Arnd Bergmann <arnd@arndb.de>

Thanks!

> for the whole series.

-- 
Sincerely yours,
Mike.