mm/memory_hotplug: allow arch_remove_memory() without CONFIG_MEMORY_H…

…OTREMOVE

We want to improve error handling while adding memory by allowing to use
arch_remove_memory() and __remove_pages() even if
CONFIG_MEMORY_HOTREMOVE is not set to e.g., implement something like:

	arch_add_memory()
	rc = do_something();
	if (rc) {
		arch_remove_memory();
	}

We won't get rid of CONFIG_MEMORY_HOTREMOVE for now, as it will require
quite some dependencies for memory offlining.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Reviewed-by: Pavel Tatashin <[email protected]>
Cc: Tony Luck <[email protected]>
Cc: Fenghua Yu <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Alex Deucher <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Mark Brown <[email protected]>
Cc: Chris Wilson <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Masahiro Yamada <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: Andrew Banman <[email protected]>
Cc: Arun KS <[email protected]>
Cc: Qian Cai <[email protected]>
Cc: Mathieu Malaterre <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: Logan Gunthorpe <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Chintan Pandya <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jonathan Cameron <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Jun Yao <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Robin Murphy <[email protected]>
Cc: Wei Yang <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Yu Zhao <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

arch/arm64/mm/mmu.c

@@ -1074,7 +1074,6 @@ int arch_add_memory(int nid, u64 start, u64 size,
 	return __add_pages(nid, start >> PAGE_SHIFT, size >> PAGE_SHIFT,
 			   restrictions);
 }
-#ifdef CONFIG_MEMORY_HOTREMOVE
 void arch_remove_memory(int nid, u64 start, u64 size,
 			struct vmem_altmap *altmap)
 {
@@ -1093,4 +1092,3 @@ void arch_remove_memory(int nid, u64 start, u64 size,
 	__remove_pages(zone, start_pfn, nr_pages, altmap);
 }
 #endif
-#endif

arch/ia64/mm/init.c

@@ -681,7 +681,6 @@ int arch_add_memory(int nid, u64 start, u64 size,
 	return ret;
 }
 
-#ifdef CONFIG_MEMORY_HOTREMOVE
 void arch_remove_memory(int nid, u64 start, u64 size,
 			struct vmem_altmap *altmap)
 {
@@ -693,4 +692,3 @@ void arch_remove_memory(int nid, u64 start, u64 size,
 	__remove_pages(zone, start_pfn, nr_pages, altmap);
 }
 #endif
-#endif

arch/powerpc/mm/mem.c

@@ -125,7 +125,6 @@ int __ref arch_add_memory(int nid, u64 start, u64 size,
 	return __add_pages(nid, start_pfn, nr_pages, restrictions);
 }
 
-#ifdef CONFIG_MEMORY_HOTREMOVE
 void __ref arch_remove_memory(int nid, u64 start, u64 size,
 			     struct vmem_altmap *altmap)
 {
@@ -151,7 +150,6 @@ void __ref arch_remove_memory(int nid, u64 start, u64 size,
 		pr_warn("Hash collision while resizing HPT\n");
 }
 #endif
-#endif /* CONFIG_MEMORY_HOTPLUG */
 
 #ifndef CONFIG_NEED_MULTIPLE_NODES
 void __init mem_topology_setup(void)

arch/s390/mm/init.c

@@ -286,7 +286,6 @@ int arch_add_memory(int nid, u64 start, u64 size,
 	return rc;
 }
 
-#ifdef CONFIG_MEMORY_HOTREMOVE
 void arch_remove_memory(int nid, u64 start, u64 size,
 			struct vmem_altmap *altmap)
 {
@@ -298,5 +297,4 @@ void arch_remove_memory(int nid, u64 start, u64 size,
 	__remove_pages(zone, start_pfn, nr_pages, altmap);
 	vmem_remove_mapping(start, size);
 }
-#endif
 #endif /* CONFIG_MEMORY_HOTPLUG */

arch/sh/mm/init.c

@@ -429,7 +429,6 @@ int memory_add_physaddr_to_nid(u64 addr)
 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 #endif
 
-#ifdef CONFIG_MEMORY_HOTREMOVE
 void arch_remove_memory(int nid, u64 start, u64 size,
 			struct vmem_altmap *altmap)
 {
@@ -440,5 +439,4 @@ void arch_remove_memory(int nid, u64 start, u64 size,
 	zone = page_zone(pfn_to_page(start_pfn));
 	__remove_pages(zone, start_pfn, nr_pages, altmap);
 }
-#endif
 #endif /* CONFIG_MEMORY_HOTPLUG */

arch/x86/mm/init_32.c

@@ -860,7 +860,6 @@ int arch_add_memory(int nid, u64 start, u64 size,
 	return __add_pages(nid, start_pfn, nr_pages, restrictions);
 }
 
-#ifdef CONFIG_MEMORY_HOTREMOVE
 void arch_remove_memory(int nid, u64 start, u64 size,
 			struct vmem_altmap *altmap)
 {
@@ -872,7 +871,6 @@ void arch_remove_memory(int nid, u64 start, u64 size,
 	__remove_pages(zone, start_pfn, nr_pages, altmap);
 }
 #endif
-#endif
 
 int kernel_set_to_readonly __read_mostly;
 

arch/x86/mm/init_64.c

@@ -1198,7 +1198,6 @@ void __ref vmemmap_free(unsigned long start, unsigned long end,
 	remove_pagetable(start, end, false, altmap);
 }
 
-#ifdef CONFIG_MEMORY_HOTREMOVE
 static void __meminit
 kernel_physical_mapping_remove(unsigned long start, unsigned long end)
 {
@@ -1219,7 +1218,6 @@ void __ref arch_remove_memory(int nid, u64 start, u64 size,
 	__remove_pages(zone, start_pfn, nr_pages, altmap);
 	kernel_physical_mapping_remove(start, start + size);
 }
-#endif
 #endif /* CONFIG_MEMORY_HOTPLUG */
 
 static struct kcore_list kcore_vsyscall;

drivers/base/memory.c

@@ -723,7 +723,6 @@ int hotplug_memory_register(int nid, struct mem_section *section)
 	return ret;
 }
 
-#ifdef CONFIG_MEMORY_HOTREMOVE
 static void
 unregister_memory(struct memory_block *memory)
 {
@@ -762,7 +761,6 @@ void unregister_memory_section(struct mem_section *section)
 out_unlock:
 	mutex_unlock(&mem_sysfs_mutex);
 }
-#endif /* CONFIG_MEMORY_HOTREMOVE */
 
 /* return true if the memory block is offlined, otherwise, return false */
 bool is_memblock_offlined(struct memory_block *mem)

include/linux/memory.h

@@ -112,9 +112,7 @@ extern void unregister_memory_notifier(struct notifier_block *nb);
 extern int register_memory_isolate_notifier(struct notifier_block *nb);
 extern void unregister_memory_isolate_notifier(struct notifier_block *nb);
 int hotplug_memory_register(int nid, struct mem_section *section);
-#ifdef CONFIG_MEMORY_HOTREMOVE
 extern void unregister_memory_section(struct mem_section *);
-#endif
 extern int memory_dev_init(void);
 extern int memory_notify(unsigned long val, void *v);
 extern int memory_isolate_notify(unsigned long val, void *v);

include/linux/memory_hotplug.h

@@ -123,12 +123,10 @@ static inline bool movable_node_is_enabled(void)
 	return movable_node_enabled;
 }
 
-#ifdef CONFIG_MEMORY_HOTREMOVE
 extern void arch_remove_memory(int nid, u64 start, u64 size,
 			       struct vmem_altmap *altmap);
 extern void __remove_pages(struct zone *zone, unsigned long start_pfn,
 			   unsigned long nr_pages, struct vmem_altmap *altmap);
-#endif /* CONFIG_MEMORY_HOTREMOVE */
 
 /*
  * Do we want sysfs memblock files created. This will allow userspace to online

mm/memory_hotplug.c

@@ -318,7 +318,6 @@ int __ref __add_pages(int nid, unsigned long phys_start_pfn,
 	return err;
 }
 
-#ifdef CONFIG_MEMORY_HOTREMOVE
 /* find the smallest valid pfn in the range [start_pfn, end_pfn) */
 static unsigned long find_smallest_section_pfn(int nid, struct zone *zone,
 				     unsigned long start_pfn,
@@ -580,7 +579,6 @@ void __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
 
 	set_zone_contiguous(zone);
 }
-#endif /* CONFIG_MEMORY_HOTREMOVE */
 
 int set_online_page_callback(online_page_callback_t callback)
 {

mm/sparse.c

@@ -604,15 +604,13 @@ static void __kfree_section_memmap(struct page *memmap,
 
 	vmemmap_free(start, end, altmap);
 }
-#ifdef CONFIG_MEMORY_HOTREMOVE
 static void free_map_bootmem(struct page *memmap)
 {
 	unsigned long start = (unsigned long)memmap;
 	unsigned long end = (unsigned long)(memmap + PAGES_PER_SECTION);
 
 	vmemmap_free(start, end, NULL);
 }
-#endif /* CONFIG_MEMORY_HOTREMOVE */
 #else
 static struct page *__kmalloc_section_memmap(void)
 {
@@ -651,7 +649,6 @@ static void __kfree_section_memmap(struct page *memmap,
 			   get_order(sizeof(struct page) * PAGES_PER_SECTION));
 }
 
-#ifdef CONFIG_MEMORY_HOTREMOVE
 static void free_map_bootmem(struct page *memmap)
 {
 	unsigned long maps_section_nr, removing_section_nr, i;
@@ -681,7 +678,6 @@ static void free_map_bootmem(struct page *memmap)
 			put_page_bootmem(page);
 	}
 }
-#endif /* CONFIG_MEMORY_HOTREMOVE */
 #endif /* CONFIG_SPARSEMEM_VMEMMAP */
 
 /**
@@ -746,7 +742,6 @@ int __meminit sparse_add_one_section(int nid, unsigned long start_pfn,
 	return ret;
 }
 
-#ifdef CONFIG_MEMORY_HOTREMOVE
 #ifdef CONFIG_MEMORY_FAILURE
 static void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
 {
@@ -823,5 +818,4 @@ void sparse_remove_one_section(struct zone *zone, struct mem_section *ms,
 			PAGES_PER_SECTION - map_offset);
 	free_section_usemap(memmap, usemap, altmap);
 }
-#endif /* CONFIG_MEMORY_HOTREMOVE */
 #endif /* CONFIG_MEMORY_HOTPLUG */