[PATCH v2 3/8] mm/memory_hotplug: arch_remove_memory() and __remove_pages() with CONFIG_MEMORY_HOTPLUG

Dan Williams dan.j.williams at intel.com
Wed May 8 07:02:03 AEST 2019


On Tue, May 7, 2019 at 11:38 AM David Hildenbrand <david at redhat.com> wrote:
>
> Let's prepare for better error handling while adding memory by allowing
> to use arch_remove_memory() and __remove_pages() even if
> CONFIG_MEMORY_HOTREMOVE is not set. CONFIG_MEMORY_HOTREMOVE effectively
> covers
> - Offlining of system ram (memory block devices) - offline_pages()
> - Unplug of system ram - remove_memory()
> - Unplug/remap of device memory - devm_memremap()
>
> This allows e.g. for handling like
>
> arch_add_memory()
> rc = do_something();
> if (rc) {
>         arch_remove_memory();
> }
>
> Whereby do_something() will for example be memory block device creation
> after it has been factored out.

What's left after this? Can we just get rid of CONFIG_MEMORY_HOTREMOVE
option completely when CONFIG_MEMORY_HOTPLUG is enabled? It's not
clear to me why there was ever the option to compile out the remove
code when the add code is included.

> Cc: Tony Luck <tony.luck at intel.com>
> Cc: Fenghua Yu <fenghua.yu at intel.com>
> Cc: Benjamin Herrenschmidt <benh at kernel.crashing.org>
> Cc: Paul Mackerras <paulus at samba.org>
> Cc: Michael Ellerman <mpe at ellerman.id.au>
> Cc: Martin Schwidefsky <schwidefsky at de.ibm.com>
> Cc: Heiko Carstens <heiko.carstens at de.ibm.com>
> Cc: Yoshinori Sato <ysato at users.sourceforge.jp>
> Cc: Rich Felker <dalias at libc.org>
> Cc: Dave Hansen <dave.hansen at linux.intel.com>
> Cc: Andy Lutomirski <luto at kernel.org>
> Cc: Peter Zijlstra <peterz at infradead.org>
> Cc: Thomas Gleixner <tglx at linutronix.de>
> Cc: Ingo Molnar <mingo at redhat.com>
> Cc: Borislav Petkov <bp at alien8.de>
> Cc: "H. Peter Anvin" <hpa at zytor.com>
> Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
> Cc: "Rafael J. Wysocki" <rafael at kernel.org>
> Cc: Andrew Morton <akpm at linux-foundation.org>
> Cc: Michal Hocko <mhocko at suse.com>
> Cc: Mike Rapoport <rppt at linux.ibm.com>
> Cc: David Hildenbrand <david at redhat.com>
> Cc: Oscar Salvador <osalvador at suse.com>
> Cc: "Kirill A. Shutemov" <kirill.shutemov at linux.intel.com>
> Cc: Alex Deucher <alexander.deucher at amd.com>
> Cc: "David S. Miller" <davem at davemloft.net>
> Cc: Mark Brown <broonie at kernel.org>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Christophe Leroy <christophe.leroy at c-s.fr>
> Cc: Nicholas Piggin <npiggin at gmail.com>
> Cc: Vasily Gorbik <gor at linux.ibm.com>
> Cc: Rob Herring <robh at kernel.org>
> Cc: Masahiro Yamada <yamada.masahiro at socionext.com>
> Cc: "mike.travis at hpe.com" <mike.travis at hpe.com>
> Cc: Andrew Banman <andrew.banman at hpe.com>
> Cc: Pavel Tatashin <pasha.tatashin at soleen.com>
> Cc: Wei Yang <richardw.yang at linux.intel.com>
> Cc: Arun KS <arunks at codeaurora.org>
> Cc: Qian Cai <cai at lca.pw>
> Cc: Mathieu Malaterre <malat at debian.org>
> Cc: Baoquan He <bhe at redhat.com>
> Cc: Logan Gunthorpe <logang at deltatee.com>
> Signed-off-by: David Hildenbrand <david at redhat.com>
> ---
>  arch/ia64/mm/init.c            | 2 --
>  arch/powerpc/mm/mem.c          | 2 --
>  arch/s390/mm/init.c            | 2 --
>  arch/sh/mm/init.c              | 2 --
>  arch/x86/mm/init_32.c          | 2 --
>  arch/x86/mm/init_64.c          | 2 --
>  drivers/base/memory.c          | 2 --
>  include/linux/memory.h         | 2 --
>  include/linux/memory_hotplug.h | 2 --
>  mm/memory_hotplug.c            | 2 --
>  mm/sparse.c                    | 6 ------
>  11 files changed, 26 deletions(-)
>
> diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
> index d28e29103bdb..aae75fd7b810 100644
> --- a/arch/ia64/mm/init.c
> +++ b/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
> diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
> index a2b78e72452f..ddc69b59575c 100644
> --- a/arch/powerpc/mm/mem.c
> +++ b/arch/powerpc/mm/mem.c
> @@ -131,7 +131,6 @@ 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)
>  {
> @@ -164,7 +163,6 @@ void __ref arch_remove_memory(int nid, u64 start, u64 size,
>         resize_hpt_for_hotplug(memblock_phys_mem_size());
>  }
>  #endif
> -#endif /* CONFIG_MEMORY_HOTPLUG */
>
>  #ifndef CONFIG_NEED_MULTIPLE_NODES
>  void __init mem_topology_setup(void)
> diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
> index 1e0cbae69f12..eafa3c750efc 100644
> --- a/arch/s390/mm/init.c
> +++ b/arch/s390/mm/init.c
> @@ -233,7 +233,6 @@ 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)
>  {
> @@ -245,5 +244,4 @@ 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 */
> diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
> index 5aeb4d7099a1..59c5fe511f25 100644
> --- a/arch/sh/mm/init.c
> +++ b/arch/sh/mm/init.c
> @@ -428,7 +428,6 @@ 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)
>  {
> @@ -439,5 +438,4 @@ 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 */
> diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
> index 075e568098f2..8d4bf2d97d50 100644
> --- a/arch/x86/mm/init_32.c
> +++ b/arch/x86/mm/init_32.c
> @@ -859,7 +859,6 @@ 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)
>  {
> @@ -871,7 +870,6 @@ 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;
>
> diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
> index 20d14254b686..f1b55ddea23f 100644
> --- a/arch/x86/mm/init_64.c
> +++ b/arch/x86/mm/init_64.c
> @@ -1131,7 +1131,6 @@ 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)
>  {
> @@ -1156,7 +1155,6 @@ 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;
> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> index f180427e48f4..6e0cb4fda179 100644
> --- a/drivers/base/memory.c
> +++ b/drivers/base/memory.c
> @@ -728,7 +728,6 @@ int hotplug_memory_register(int nid, struct mem_section *section)
>         return ret;
>  }
>
> -#ifdef CONFIG_MEMORY_HOTREMOVE
>  static void
>  unregister_memory(struct memory_block *memory)
>  {
> @@ -767,7 +766,6 @@ 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)
> diff --git a/include/linux/memory.h b/include/linux/memory.h
> index e1dc1bb2b787..474c7c60c8f2 100644
> --- a/include/linux/memory.h
> +++ b/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);
> diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
> index ae892eef8b82..2d4de313926d 100644
> --- a/include/linux/memory_hotplug.h
> +++ b/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
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 202febe88b58..7b5439839d67 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -317,7 +317,6 @@ 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,
> @@ -581,7 +580,6 @@ 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)
>  {
> diff --git a/mm/sparse.c b/mm/sparse.c
> index fd13166949b5..d1d5e05f5b8d 100644
> --- a/mm/sparse.c
> +++ b/mm/sparse.c
> @@ -604,7 +604,6 @@ 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;
> @@ -612,7 +611,6 @@ static void free_map_bootmem(struct page *memmap)
>
>         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 */
> --
> 2.20.1
>


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