This is a note to let you know that I've just added the patch titled mm/memory_hotplug: make __remove_pages() and arch_remove_memory() never fail to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mm-memory_hotplug-make-__remove_pages-and-arch_remove_memory-never-fail.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Tue 28 Jan 2020 02:32:10 PM CET From: David Hildenbrand <david@xxxxxxxxxx> Date: Tue, 28 Jan 2020 10:50:09 +0100 Subject: mm/memory_hotplug: make __remove_pages() and arch_remove_memory() never fail To: stable@xxxxxxxxxxxxxxx Cc: linux-mm@xxxxxxxxx, Michal Hocko <mhocko@xxxxxxxx>, Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>, "Aneesh Kumar K . V" <aneesh.kumar@xxxxxxxxxxxxx>, Baoquan He <bhe@xxxxxxxxxx>, Dan Williams <dan.j.williams@xxxxxxxxx>, Oscar Salvador <osalvador@xxxxxxx>, Wei Yang <richard.weiyang@xxxxxxxxx>, David Hildenbrand <david@xxxxxxxxxx> Message-ID: <20200128095021.8076-13-david@xxxxxxxxxx> From: David Hildenbrand <david@xxxxxxxxxx> commit ac5c94264580f498e484c854031d0226b3c1038f upstream. -- snip -- Minor conflict in arch/powerpc/mm/mem.c -- snip -- 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@xxxxxxxxxx Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> Cc: Tony Luck <tony.luck@xxxxxxxxx> Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx> Cc: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx> Cc: Rich Felker <dalias@xxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Mike Rapoport <rppt@xxxxxxxxxxxxx> Cc: Oscar Salvador <osalvador@xxxxxxxx> Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Christophe Leroy <christophe.leroy@xxxxxx> Cc: Stefan Agner <stefan@xxxxxxxx> Cc: Nicholas Piggin <npiggin@xxxxxxxxx> Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx> Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx> Cc: Arun KS <arunks@xxxxxxxxxxxxxx> Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> Cc: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> Cc: Rob Herring <robh@xxxxxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: Wei Yang <richard.weiyang@xxxxxxxxx> Cc: Qian Cai <cai@xxxxxx> Cc: Mathieu Malaterre <malat@xxxxxxxxxx> Cc: Andrew Banman <andrew.banman@xxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Mike Travis <mike.travis@xxxxxxx> Cc: Oscar Salvador <osalvador@xxxxxxx> Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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(-) --- a/arch/ia64/mm/init.c +++ b/arch/ia64/mm/init.c @@ -662,20 +662,15 @@ int arch_add_memory(int nid, u64 start, } #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 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -140,7 +140,7 @@ int __ref arch_add_memory(int nid, u64 s } #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; @@ -156,14 +156,13 @@ int __ref arch_remove_memory(int nid, u6 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 @@ -171,8 +170,6 @@ int __ref arch_remove_memory(int nid, u6 vm_unmap_aliases(); resize_hpt_for_hotplug(memblock_phys_mem_size()); - - return ret; } #endif #endif /* CONFIG_MEMORY_HOTPLUG */ --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -240,14 +240,15 @@ int arch_add_memory(int nid, u64 start, } #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 */ --- a/arch/sh/mm/init.c +++ b/arch/sh/mm/init.c @@ -444,20 +444,15 @@ EXPORT_SYMBOL_GPL(memory_add_physaddr_to #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 */ --- a/arch/x86/mm/init_32.c +++ b/arch/x86/mm/init_32.c @@ -861,14 +861,15 @@ int arch_add_memory(int nid, u64 start, } #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 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -1142,24 +1142,20 @@ kernel_physical_mapping_remove(unsigned 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 */ --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -109,10 +109,10 @@ static inline bool movable_node_is_enabl } #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 */ /* reasonably generic interface to expand the physical pages */ --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -509,8 +509,8 @@ static void __remove_section(struct zone * 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; @@ -541,7 +541,6 @@ int __remove_pages(struct zone *zone, un } set_zone_contiguous(zone); - return 0; } #endif /* CONFIG_MEMORY_HOTREMOVE */ Patches currently in stable-queue which might be from david@xxxxxxxxxx are queue-4.19/mm-memory_hotplug-remove-memory-block-devices-before-arch_remove_memory.patch queue-4.19/mm-hotplug-kill-is_dev_zone-usage-in-__remove_pages.patch queue-4.19/mm-memory_hotplug-create-memory-block-devices-after-arch_add_memory.patch queue-4.19/drivers-base-memory-pass-a-block_id-to-init_memory_block.patch queue-4.19/drivers-base-memory.c-clean-up-relics-in-function-parameters.patch queue-4.19/mm-memory_hotplug-update-a-comment-in-unregister_memory.patch queue-4.19/mm-memory_hotplug-shrink-zones-when-offlining-memory.patch queue-4.19/mm-memory_hotplug-make-unregister_memory_block_under_nodes-never-fail.patch queue-4.19/mm-memunmap-don-t-access-uninitialized-memmap-in-memunmap_pages.patch queue-4.19/mm-memory_hotplug-make-__remove_section-never-fail.patch queue-4.19/mm-sparse-drop-pgdat_resize_lock-in-sparse_add-remove_one_section.patch queue-4.19/mm-memory_hotplug-make-unregister_memory_section-never-fail.patch queue-4.19/mm-memory_hotplug-release-memory-resource-after-arch_remove_memory.patch queue-4.19/mm-memory_hotplug-add-nid-parameter-to-arch_remove_memory.patch queue-4.19/powerpc-mm-fix-section-mismatch-warning.patch queue-4.19/mm-memory_hotplug-allow-arch_remove_memory-without-config_memory_hotremove.patch queue-4.19/mm-memory_hotplug-make-remove_memory-take-the-device_hotplug_lock.patch queue-4.19/mm-memory_hotplug-make-__remove_pages-and-arch_remove_memory-never-fail.patch queue-4.19/mm-memory_hotplug-fix-try_offline_node.patch queue-4.19/mm-memory_hotplug-remove-zone-parameter-from-sparse_remove_one_section.patch queue-4.19/drivers-base-memory.c-remove-an-unnecessary-check-on-nr_mem_sections.patch queue-4.19/drivers-base-node.c-simplify-unregister_memory_block_under_nodes.patch queue-4.19/s390x-mm-implement-arch_remove_memory.patch queue-4.19/mm-sparse-pass-nid-instead-of-pgdat-to-sparse_add_one_section.patch