From ac5c94264580f498e484c854031d0226b3c1038f Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Mon, 13 May 2019 17:21:46 -0700 Subject: [PATCH] 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: David Hildenbrand Cc: Tony Luck Cc: Fenghua Yu Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Yoshinori Sato Cc: Rich Felker Cc: Dave Hansen Cc: Andy Lutomirski Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: Michal Hocko Cc: Mike Rapoport Cc: Oscar Salvador Cc: "Kirill A. Shutemov" Cc: Christophe Leroy Cc: Stefan Agner Cc: Nicholas Piggin Cc: Pavel Tatashin Cc: Vasily Gorbik Cc: Arun KS Cc: Geert Uytterhoeven Cc: Masahiro Yamada Cc: Rob Herring Cc: Joonsoo Kim Cc: Wei Yang Cc: Qian Cai Cc: Mathieu Malaterre Cc: Andrew Banman Cc: Greg Kroah-Hartman Cc: Ingo Molnar Cc: Mike Travis Cc: Oscar Salvador Cc: "Rafael J. Wysocki" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/ia64/mm/init.c | 11 +++-------- arch/powerpc/mm/mem.c | 9 +++------ arch/s390/mm/init.c | 5 +++-- arch/sh/mm/init.c | 11 +++-------- arch/x86/mm/init_32.c | 5 +++-- arch/x86/mm/init_64.c | 10 +++------- include/linux/memory_hotplug.h | 8 ++++---- mm/memory_hotplug.c | 5 ++--- 8 files changed, 24 insertions(+), 40 deletions(-) diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c index 379eb1f9adc9..d28e29103bdb 100644 --- a/arch/ia64/mm/init.c +++ b/arch/ia64/mm/init.c @@ -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 diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c index de5c591a550d..e885fe2aafcc 100644 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -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 */ diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index 06bd05137a00..14d1eae9fe43 100644 --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -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 */ diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c index d3cd07bd2dc1..b95e343e3c9d 100644 --- a/arch/sh/mm/init.c +++ b/arch/sh/mm/init.c @@ -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 */ diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c index 755dbed85531..075e568098f2 100644 --- a/arch/x86/mm/init_32.c +++ b/arch/x86/mm/init_32.c @@ -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 diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index db42c11b48fb..20d14254b686 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -1141,24 +1141,20 @@ kernel_physical_mapping_remove(unsigned long start, unsigned long end) remove_pagetable(start, end, true, NULL); } -int __ref arch_remove_memory(int nid, u64 start, u64 size, - struct vmem_altmap *altmap) +void __ref 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 page *page = pfn_to_page(start_pfn); struct zone *zone; - int ret; /* With altmap the first mapped page is offset from @start */ if (altmap) page += vmem_altmap_offset(altmap); zone = page_zone(page); - ret = __remove_pages(zone, start_pfn, nr_pages, altmap); - WARN_ON_ONCE(ret); + __remove_pages(zone, start_pfn, nr_pages, altmap); kernel_physical_mapping_remove(start, start + size); - - return ret; } #endif #endif /* CONFIG_MEMORY_HOTPLUG */ diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index b24aca54353e..ae892eef8b82 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -124,10 +124,10 @@ static inline bool movable_node_is_enabled(void) } #ifdef CONFIG_MEMORY_HOTREMOVE -extern int arch_remove_memory(int nid, u64 start, u64 size, - struct vmem_altmap *altmap); -extern int __remove_pages(struct zone *zone, unsigned long start_pfn, - unsigned long nr_pages, struct vmem_altmap *altmap); +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 */ /* diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 3512bba20e2b..6c0c4f48638e 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -547,8 +547,8 @@ static void __remove_section(struct zone *zone, struct mem_section *ms, * sure that pages are marked reserved and zones are adjust properly by * calling offline_pages(). */ -int __remove_pages(struct zone *zone, unsigned long phys_start_pfn, - unsigned long nr_pages, struct vmem_altmap *altmap) +void __remove_pages(struct zone *zone, unsigned long phys_start_pfn, + unsigned long nr_pages, struct vmem_altmap *altmap) { unsigned long i; unsigned long map_offset = 0; @@ -579,7 +579,6 @@ int __remove_pages(struct zone *zone, unsigned long phys_start_pfn, } set_zone_contiguous(zone); - return 0; } #endif /* CONFIG_MEMORY_HOTREMOVE */