Commit ac5c9426 authored by David Hildenbrand's avatar David Hildenbrand Committed by Linus Torvalds
Browse files

mm/memory_hotplug: make __remove_pages() and arch_remove_memory() never fail 

All callers of arch_remove_memory() ignore errors.  And we should really
try to remove any errors from the memory removal path.  No more errors are
reported from __remove_pages().  BUG() in s390x code in case
arch_remove_memory() is triggered.  We may implement that properly later.
WARN in case powerpc code failed to remove the section mapping, which is
better than ignoring the error completely right now.

Link: http://lkml.kernel.org/r/20190409100148.24703-5-david@redhat.com


Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Oscar Salvador <osalvador@suse.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Andrew Banman <andrew.banman@hpe.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mike Travis <mike.travis@hpe.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 9d1d887d

arch/ia64/mm/init.c

+3 −8
Original line number Diff line number Diff line
@@ -682,20 +682,15 @@ int arch_add_memory(int nid, u64 start, u64 size, 
}



#ifdef CONFIG_MEMORY_HOTREMOVE

int arch_remove_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap)

void arch_remove_memory(int nid, u64 start, u64 size,

			struct vmem_altmap *altmap)

{

	unsigned long start_pfn = start >> PAGE_SHIFT;

	unsigned long nr_pages = size >> PAGE_SHIFT;

	struct zone *zone;

	int ret;



	zone = page_zone(pfn_to_page(start_pfn));

	ret = __remove_pages(zone, start_pfn, nr_pages, altmap);

	if (ret)

		pr_warn("%s: Problem encountered in __remove_pages() as"

			" ret=%d\n", __func__,  ret);



	return ret;

	__remove_pages(zone, start_pfn, nr_pages, altmap);

}

#endif

#endif

arch/powerpc/mm/mem.c

+3 −6
Original line number Diff line number Diff line
@@ -131,7 +131,7 @@ int __ref arch_add_memory(int nid, u64 start, u64 size, 
}



#ifdef CONFIG_MEMORY_HOTREMOVE

int __ref arch_remove_memory(int nid, u64 start, u64 size,

void __ref arch_remove_memory(int nid, u64 start, u64 size,

			     struct vmem_altmap *altmap)

{

	unsigned long start_pfn = start >> PAGE_SHIFT;
@@ -147,14 +147,13 @@ int __ref arch_remove_memory(int nid, u64 start, u64 size, 
	if (altmap)

		page += vmem_altmap_offset(altmap);



	ret = __remove_pages(page_zone(page), start_pfn, nr_pages, altmap);

	if (ret)

		return ret;

	__remove_pages(page_zone(page), start_pfn, nr_pages, altmap);



	/* Remove htab bolted mappings for this section of memory */

	start = (unsigned long)__va(start);

	flush_inval_dcache_range(start, start + size);

	ret = remove_section_mapping(start, start + size);

	WARN_ON_ONCE(ret);



	/* Ensure all vmalloc mappings are flushed in case they also

	 * hit that section of memory
@@ -163,8 +162,6 @@ int __ref arch_remove_memory(int nid, u64 start, u64 size, 


	if (resize_hpt_for_hotplug(memblock_phys_mem_size()) == -ENOSPC)

		pr_warn("Hash collision while resizing HPT\n");



	return ret;

}

#endif

#endif /* CONFIG_MEMORY_HOTPLUG */

arch/s390/mm/init.c

+3 −2
Original line number Diff line number Diff line
@@ -237,14 +237,15 @@ int arch_add_memory(int nid, u64 start, u64 size, 
}



#ifdef CONFIG_MEMORY_HOTREMOVE

int arch_remove_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap)

void arch_remove_memory(int nid, u64 start, u64 size,

			struct vmem_altmap *altmap)

{

	/*

	 * There is no hardware or firmware interface which could trigger a

	 * hot memory remove on s390. So there is nothing that needs to be

	 * implemented.

	 */

	return -EBUSY;

	BUG();

}

#endif

#endif /* CONFIG_MEMORY_HOTPLUG */

arch/sh/mm/init.c

+3 −8
Original line number Diff line number Diff line
@@ -429,20 +429,15 @@ EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid); 
#endif



#ifdef CONFIG_MEMORY_HOTREMOVE

int arch_remove_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap)

void arch_remove_memory(int nid, u64 start, u64 size,

			struct vmem_altmap *altmap)

{

	unsigned long start_pfn = PFN_DOWN(start);

	unsigned long nr_pages = size >> PAGE_SHIFT;

	struct zone *zone;

	int ret;



	zone = page_zone(pfn_to_page(start_pfn));

	ret = __remove_pages(zone, start_pfn, nr_pages, altmap);

	if (unlikely(ret))

		pr_warn("%s: Failed, __remove_pages() == %d\n", __func__,

			ret);



	return ret;

	__remove_pages(zone, start_pfn, nr_pages, altmap);

}

#endif

#endif /* CONFIG_MEMORY_HOTPLUG */

arch/x86/mm/init_32.c

+3 −2
Original line number Diff line number Diff line
@@ -860,14 +860,15 @@ int arch_add_memory(int nid, u64 start, u64 size, 
}



#ifdef CONFIG_MEMORY_HOTREMOVE

int arch_remove_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap)

void arch_remove_memory(int nid, u64 start, u64 size,

			struct vmem_altmap *altmap)

{

	unsigned long start_pfn = start >> PAGE_SHIFT;

	unsigned long nr_pages = size >> PAGE_SHIFT;

	struct zone *zone;



	zone = page_zone(pfn_to_page(start_pfn));

	return __remove_pages(zone, start_pfn, nr_pages, altmap);

	__remove_pages(zone, start_pfn, nr_pages, altmap);

}

#endif

#endif

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