From: Wei Yang richard.weiyang@gmail.com

commit 83af658898cb292a32d8b6cd9b51266d7cfc4b6a upstream.

pgdat_resize_lock is used to protect pgdat's memory region information like: node_start_pfn, node_present_pages, etc. While in function sparse_add/remove_one_section(), pgdat_resize_lock is used to protect initialization/release of one mem_section. This looks not proper.

These code paths are currently protected by mem_hotplug_lock currently but should there ever be any reason for locking at the sparse layer a dedicated lock should be introduced.

Following is the current call trace of sparse_add/remove_one_section()

mem_hotplug_begin() arch_add_memory() add_pages() __add_pages() __add_section() sparse_add_one_section() mem_hotplug_done()

mem_hotplug_begin() arch_remove_memory() __remove_pages() __remove_section() sparse_remove_one_section() mem_hotplug_done()

The comment above the pgdat_resize_lock also mentions "Holding this will also guarantee that any pfn_valid() stays that way.", which is true with the current implementation and false after this patch. But current implementation doesn't meet this comment. There isn't any pfn walkers to take the lock so this looks like a relict from the past. This patch also removes this comment.

[richard.weiyang@gmail.com: v4] Link: http://lkml.kernel.org/r/20181204085657.20472-1-richard.weiyang@gmail.com [mhocko@suse.com: changelog suggestion] Link: http://lkml.kernel.org/r/20181128091243.19249-1-richard.weiyang@gmail.com Signed-off-by: Wei Yang richard.weiyang@gmail.com Reviewed-by: David Hildenbrand david@redhat.com Acked-by: Michal Hocko mhocko@suse.com Cc: Dave Hansen dave.hansen@intel.com Cc: Oscar Salvador osalvador@suse.de Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: David Hildenbrand david@redhat.com --- include/linux/mmzone.h | 3 +-- mm/sparse.c | 9 +-------- 2 files changed, 2 insertions(+), 10 deletions(-)

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index d4b0c79d2924..d6791e2df30a 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -637,8 +637,7 @@ typedef struct pglist_data { #if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT) /* * Must be held any time you expect node_start_pfn, node_present_pages - * or node_spanned_pages stay constant. Holding this will also - * guarantee that any pfn_valid() stays that way. + * or node_spanned_pages stay constant. * * pgdat_resize_lock() and pgdat_resize_unlock() are provided to * manipulate node_size_lock without checking for CONFIG_MEMORY_HOTPLUG diff --git a/mm/sparse.c b/mm/sparse.c index 45950a074bdb..9aca9f24bdc5 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -668,7 +668,6 @@ int __meminit sparse_add_one_section(struct pglist_data *pgdat, struct mem_section *ms; struct page *memmap; unsigned long *usemap; - unsigned long flags; int ret;

/* @@ -688,8 +687,6 @@ int __meminit sparse_add_one_section(struct pglist_data *pgdat, return -ENOMEM; }

- pgdat_resize_lock(pgdat, &flags); - ms = __pfn_to_section(start_pfn); if (ms->section_mem_map & SECTION_MARKED_PRESENT) { ret = -EEXIST; @@ -708,7 +705,6 @@ int __meminit sparse_add_one_section(struct pglist_data *pgdat, sparse_init_one_section(ms, section_nr, memmap, usemap);

out: - pgdat_resize_unlock(pgdat, &flags); if (ret < 0) { kfree(usemap); __kfree_section_memmap(memmap, altmap); @@ -770,10 +766,8 @@ void sparse_remove_one_section(struct zone *zone, struct mem_section *ms, unsigned long map_offset, struct vmem_altmap *altmap) { struct page *memmap = NULL; - unsigned long *usemap = NULL, flags; - struct pglist_data *pgdat = zone->zone_pgdat; + unsigned long *usemap = NULL;

- pgdat_resize_lock(pgdat, &flags); if (ms->section_mem_map) { usemap = ms->pageblock_flags; memmap = sparse_decode_mem_map(ms->section_mem_map, @@ -781,7 +775,6 @@ void sparse_remove_one_section(struct zone *zone, struct mem_section *ms, ms->section_mem_map = 0; ms->pageblock_flags = NULL; } - pgdat_resize_unlock(pgdat, &flags);

clear_hwpoisoned_pages(memmap + map_offset, PAGES_PER_SECTION - map_offset);

From: Wei Yang richard.weiyang@gmail.com

commit 3b6fd6ffb27c2efa003c6d4d15ca72c054b71d7c upstream.

In cb5e39b8038b ("drivers: base: refactor add_memory_section() to add_memory_block()"), add_memory_block() is introduced, which is only invoked in memory_dev_init().

When combining these two loops in memory_dev_init() and add_memory_block(), they looks like this:

for (i = 0; i < NR_MEM_SECTIONS; i += sections_per_block) for (j = i; (j < i + sections_per_block) && j < NR_MEM_SECTIONS; j++)

Since it is sure the (i < NR_MEM_SECTIONS) and j sits in its own memory block, the check of (j < NR_MEM_SECTIONS) is not necessary.

This patch just removes this check.

Link: http://lkml.kernel.org/r/20181123222811.18216-1-richard.weiyang@gmail.com Signed-off-by: Wei Yang richard.weiyang@gmail.com Reviewed-by: Andrew Morton akpm@linux-foundation.org Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: "Rafael J. Wysocki" rafael@kernel.org Cc: Seth Jennings sjenning@redhat.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: David Hildenbrand david@redhat.com --- drivers/base/memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/base/memory.c b/drivers/base/memory.c index ac1574a69610..5fca7225f3fe 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -691,7 +691,7 @@ static int add_memory_block(int base_section_nr) int i, ret, section_count = 0, section_nr;

for (i = base_section_nr; - (i < base_section_nr + sections_per_block) && i < NR_MEM_SECTIONS; + i < base_section_nr + sections_per_block; i++) { if (!present_section_nr(i)) continue;

commit d9eb1417c77df7ce19abd2e41619e9dceccbdf2a upstream.

Patch series "mm/memory_hotplug: Better error handling when removing memory", v1.

Error handling when removing memory is somewhat messed up right now. Some errors result in warnings, others are completely ignored. Memory unplug code can essentially not deal with errors properly as of now. remove_memory() will never fail.

We have basically two choices: 1. Allow arch_remov_memory() and friends to fail, propagating errors via remove_memory(). Might be problematic (e.g. DIMMs consisting of multiple pieces added/removed separately). 2. Don't allow the functions to fail, handling errors in a nicer way.

It seems like most errors that can theoretically happen are really corner cases and mostly theoretical (e.g. "section not valid"). However e.g. aborting removal of sections while all callers simply continue in case of errors is not nice.

If we can gurantee that removal of memory always works (and WARN/skip in case of theoretical errors so we can figure out what is going on), we can go ahead and implement better error handling when adding memory.

E.g. via add_memory():

arch_add_memory() ret = do_stuff() if (ret) { arch_remove_memory(); goto error; }

Handling here that arch_remove_memory() might fail is basically impossible. So I suggest, let's avoid reporting errors while removing memory, warning on theoretical errors instead and continuing instead of aborting.

This patch (of 4):

__add_pages() doesn't add the memory resource, so __remove_pages() shouldn't remove it. Let's factor it out. Especially as it is a special case for memory used as system memory, added via add_memory() and friends.

We now remove the resource after removing the sections instead of doing it the other way around. I don't think this change is problematic.

add_memory() register memory resource arch_add_memory()

remove_memory arch_remove_memory() release memory resource

While at it, explain why we ignore errors and that it only happeny if we remove memory in a different granularity as we added it.

[david@redhat.com: fix printk warning] Link: http://lkml.kernel.org/r/20190417120204.6997-1-david@redhat.com Link: http://lkml.kernel.org/r/20190409100148.24703-2-david@redhat.com Signed-off-by: David Hildenbrand david@redhat.com Reviewed-by: Oscar Salvador osalvador@suse.de Cc: Michal Hocko mhocko@suse.com Cc: David Hildenbrand david@redhat.com Cc: Pavel Tatashin pasha.tatashin@soleen.com Cc: Wei Yang richard.weiyang@gmail.com Cc: Qian Cai cai@lca.pw Cc: Arun KS arunks@codeaurora.org Cc: Mathieu Malaterre malat@debian.org Cc: Andrew Banman andrew.banman@hpe.com Cc: Andy Lutomirski luto@kernel.org Cc: Benjamin Herrenschmidt benh@kernel.crashing.org Cc: Borislav Petkov bp@alien8.de Cc: Christophe Leroy christophe.leroy@c-s.fr Cc: Dave Hansen dave.hansen@linux.intel.com Cc: Fenghua Yu fenghua.yu@intel.com Cc: Geert Uytterhoeven geert@linux-m68k.org Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Heiko Carstens heiko.carstens@de.ibm.com Cc: "H. Peter Anvin" hpa@zytor.com Cc: Ingo Molnar mingo@kernel.org Cc: Ingo Molnar mingo@redhat.com Cc: Joonsoo Kim iamjoonsoo.kim@lge.com Cc: "Kirill A. Shutemov" kirill.shutemov@linux.intel.com Cc: Martin Schwidefsky schwidefsky@de.ibm.com Cc: Masahiro Yamada yamada.masahiro@socionext.com Cc: Michael Ellerman mpe@ellerman.id.au Cc: Mike Rapoport rppt@linux.ibm.com Cc: Mike Travis mike.travis@hpe.com Cc: Nicholas Piggin npiggin@gmail.com Cc: Oscar Salvador osalvador@suse.com Cc: Paul Mackerras paulus@samba.org Cc: Peter Zijlstra peterz@infradead.org Cc: "Rafael J. Wysocki" rafael@kernel.org Cc: Rich Felker dalias@libc.org Cc: Rob Herring robh@kernel.org Cc: Stefan Agner stefan@agner.ch Cc: Thomas Gleixner tglx@linutronix.de Cc: Tony Luck tony.luck@intel.com Cc: Vasily Gorbik gor@linux.ibm.com Cc: Yoshinori Sato ysato@users.sourceforge.jp Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: David Hildenbrand david@redhat.com --- mm/memory_hotplug.c | 35 +++++++++++++++++++++-------------- 1 file changed, 21 insertions(+), 14 deletions(-)

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index a51e5ffdaa04..418d589552b3 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -523,20 +523,6 @@ int __remove_pages(struct zone *zone, unsigned long phys_start_pfn, if (is_dev_zone(zone)) { if (altmap) map_offset = vmem_altmap_offset(altmap); - } else { - resource_size_t start, size; - - start = phys_start_pfn << PAGE_SHIFT; - size = nr_pages * PAGE_SIZE; - - ret = release_mem_region_adjustable(&iomem_resource, start, - size); - if (ret) { - resource_size_t endres = start + size - 1; - - pr_warn("Unable to release resource <%pa-%pa> (%d)\n", - &start, &endres, ret); - } }

clear_zone_contiguous(zone); @@ -1883,6 +1869,26 @@ void try_offline_node(int nid) } EXPORT_SYMBOL(try_offline_node);

+static void __release_memory_resource(resource_size_t start, + resource_size_t size) +{ + int ret; + + /* + * When removing memory in the same granularity as it was added, + * this function never fails. It might only fail if resources + * have to be adjusted or split. We'll ignore the error, as + * removing of memory cannot fail. + */ + ret = release_mem_region_adjustable(&iomem_resource, start, size); + if (ret) { + resource_size_t endres = start + size - 1; + + pr_warn("Unable to release resource <%pa-%pa> (%d)\n", + &start, &endres, ret); + } +} + /** * remove_memory * @nid: the node ID @@ -1917,6 +1923,7 @@ void __ref __remove_memory(int nid, u64 start, u64 size) memblock_remove(start, size);

arch_remove_memory(nid, start, size, NULL); + __release_memory_resource(start, size);

try_offline_node(nid);

From: Dan Carpenter dan.carpenter@oracle.com

commit 16df1456aa858a86f398dbc7d27649eb6662b0cc upstream.

The remove_memory_block() function was renamed to in commit cc292b0b4302 ("drivers/base/memory.c: rename remove_memory_block() to remove_memory_section()").

Signed-off-by: Dan Carpenter dan.carpenter@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: David Hildenbrand david@redhat.com --- drivers/base/memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/base/memory.c b/drivers/base/memory.c index b384f01ad29d..119b076eb5e2 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -743,7 +743,7 @@ unregister_memory(struct memory_block *memory) { BUG_ON(memory->dev.bus != &memory_subsys);

- /* drop the ref. we got in remove_memory_block() */ + /* drop the ref. we got in remove_memory_section() */ put_device(&memory->dev); device_unregister(&memory->dev); }

commit 9d1d887d785b4fe0590bd3c5e71acaa3908044e2 upstream.

Let's just warn in case a section is not valid instead of failing to remove somewhere in the middle of the process, returning an error that will be mostly ignored by callers.

Link: http://lkml.kernel.org/r/20190409100148.24703-4-david@redhat.com Signed-off-by: David Hildenbrand david@redhat.com Reviewed-by: Oscar Salvador osalvador@suse.de Cc: Michal Hocko mhocko@suse.com Cc: David Hildenbrand david@redhat.com Cc: Pavel Tatashin pasha.tatashin@soleen.com Cc: Qian Cai cai@lca.pw Cc: Wei Yang richard.weiyang@gmail.com Cc: Arun KS arunks@codeaurora.org Cc: Mathieu Malaterre malat@debian.org Cc: Andrew Banman andrew.banman@hpe.com Cc: Andy Lutomirski luto@kernel.org Cc: Benjamin Herrenschmidt benh@kernel.crashing.org Cc: Borislav Petkov bp@alien8.de Cc: Christophe Leroy christophe.leroy@c-s.fr Cc: Dave Hansen dave.hansen@linux.intel.com Cc: Fenghua Yu fenghua.yu@intel.com Cc: Geert Uytterhoeven geert@linux-m68k.org Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Heiko Carstens heiko.carstens@de.ibm.com Cc: "H. Peter Anvin" hpa@zytor.com Cc: Ingo Molnar mingo@kernel.org Cc: Ingo Molnar mingo@redhat.com Cc: Joonsoo Kim iamjoonsoo.kim@lge.com Cc: "Kirill A. Shutemov" kirill.shutemov@linux.intel.com Cc: Martin Schwidefsky schwidefsky@de.ibm.com Cc: Masahiro Yamada yamada.masahiro@socionext.com Cc: Michael Ellerman mpe@ellerman.id.au Cc: Mike Rapoport rppt@linux.ibm.com Cc: Mike Travis mike.travis@hpe.com Cc: Nicholas Piggin npiggin@gmail.com Cc: Oscar Salvador osalvador@suse.com Cc: Paul Mackerras paulus@samba.org Cc: Peter Zijlstra peterz@infradead.org Cc: "Rafael J. Wysocki" rafael@kernel.org Cc: Rich Felker dalias@libc.org Cc: Rob Herring robh@kernel.org Cc: Stefan Agner stefan@agner.ch Cc: Thomas Gleixner tglx@linutronix.de Cc: Tony Luck tony.luck@intel.com Cc: Vasily Gorbik gor@linux.ibm.com Cc: Yoshinori Sato ysato@users.sourceforge.jp Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: David Hildenbrand david@redhat.com --- mm/memory_hotplug.c | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-)

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 42c5bc371ffe..a9fcae50a33a 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -478,15 +478,15 @@ static void __remove_zone(struct zone *zone, unsigned long start_pfn) pgdat_resize_unlock(zone->zone_pgdat, &flags); }

-static int __remove_section(struct zone *zone, struct mem_section *ms, - unsigned long map_offset, struct vmem_altmap *altmap) +static void __remove_section(struct zone *zone, struct mem_section *ms, + unsigned long map_offset, + struct vmem_altmap *altmap) { unsigned long start_pfn; int scn_nr; - int ret = -EINVAL;

- if (!valid_section(ms)) - return ret; + if (WARN_ON_ONCE(!valid_section(ms))) + return;

unregister_memory_section(ms);

@@ -495,7 +495,6 @@ static int __remove_section(struct zone *zone, struct mem_section *ms, __remove_zone(zone, start_pfn);

sparse_remove_one_section(zone, ms, map_offset, altmap); - return 0; }

/** @@ -515,7 +514,7 @@ int __remove_pages(struct zone *zone, unsigned long phys_start_pfn, { unsigned long i; unsigned long map_offset = 0; - int sections_to_remove, ret = 0; + int sections_to_remove;

/* In the ZONE_DEVICE case device driver owns the memory region */ if (is_dev_zone(zone)) { @@ -536,16 +535,13 @@ int __remove_pages(struct zone *zone, unsigned long phys_start_pfn, unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION;

cond_resched(); - ret = __remove_section(zone, __pfn_to_section(pfn), map_offset, - altmap); + __remove_section(zone, __pfn_to_section(pfn), map_offset, + altmap); map_offset = 0; - if (ret) - break; }

set_zone_contiguous(zone); - - return ret; + return 0; } #endif /* CONFIG_MEMORY_HOTREMOVE */

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@redhat.com Signed-off-by: David 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: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: David Hildenbrand david@redhat.com --- 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 b54d0ee74b53..950a9e0a4548 100644 --- a/arch/ia64/mm/init.c +++ b/arch/ia64/mm/init.c @@ -662,20 +662,15 @@ int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap, }

#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 625d78547fe7..ab79f2831f9c 100644 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -140,7 +140,7 @@ int __ref arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altm }

#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, 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 @@ -171,8 +170,6 @@ int __ref arch_remove_memory(int nid, u64 start, u64 size, vm_unmap_aliases();

resize_hpt_for_hotplug(memblock_phys_mem_size()); - - return ret; } #endif #endif /* CONFIG_MEMORY_HOTPLUG */ diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index bc49b560625e..0da486d914e4 100644 --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -240,14 +240,15 @@ int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap, }

#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 5c91bb6abc35..59ae5d7dc081 100644 --- a/arch/sh/mm/init.c +++ b/arch/sh/mm/init.c @@ -444,20 +444,15 @@ 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 9fa503f2f56c..c6a50a0f240b 100644 --- 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, u64 size, struct vmem_altmap *altmap, }

#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 32066d5dc9af..b9e15f25b921 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -1142,24 +1142,20 @@ 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 df77a7597aba..04c40da0228a 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -109,10 +109,10 @@ 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 */

/* reasonably generic interface to expand the physical pages */ diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index a9fcae50a33a..7905e3275289 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -509,8 +509,8 @@ 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; @@ -541,7 +541,6 @@ int __remove_pages(struct zone *zone, unsigned long phys_start_pfn, }

set_zone_contiguous(zone); - return 0; } #endif /* CONFIG_MEMORY_HOTREMOVE */

commit 80ec922dbd87fd38d15719c86a94457204648aeb upstream.

-- snip --

Missing arm64 memory hot(un)plug support.

-- snip --

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/20190527111152.16324-7-david@redhat.com Signed-off-by: David Hildenbrand david@redhat.com Reviewed-by: Pavel Tatashin pasha.tatashin@soleen.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: 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: Borislav Petkov bp@alien8.de Cc: "H. Peter Anvin" hpa@zytor.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: "Rafael J. Wysocki" rafael@kernel.org Cc: Michal Hocko mhocko@suse.com Cc: David Hildenbrand david@redhat.com Cc: Oscar Salvador osalvador@suse.com Cc: "Kirill A. Shutemov" kirill.shutemov@linux.intel.com Cc: Alex Deucher alexander.deucher@amd.com Cc: "David S. Miller" davem@davemloft.net Cc: Mark Brown broonie@kernel.org Cc: Chris Wilson chris@chris-wilson.co.uk Cc: Christophe Leroy christophe.leroy@c-s.fr Cc: Nicholas Piggin npiggin@gmail.com Cc: Vasily Gorbik gor@linux.ibm.com Cc: Rob Herring robh@kernel.org Cc: Masahiro Yamada yamada.masahiro@socionext.com Cc: "mike.travis@hpe.com" mike.travis@hpe.com Cc: Andrew Banman andrew.banman@hpe.com Cc: Arun KS arunks@codeaurora.org Cc: Qian Cai cai@lca.pw Cc: Mathieu Malaterre malat@debian.org Cc: Baoquan He bhe@redhat.com Cc: Logan Gunthorpe logang@deltatee.com Cc: Anshuman Khandual anshuman.khandual@arm.com Cc: Ard Biesheuvel ard.biesheuvel@linaro.org Cc: Catalin Marinas catalin.marinas@arm.com Cc: Chintan Pandya cpandya@codeaurora.org Cc: Dan Williams dan.j.williams@intel.com Cc: Ingo Molnar mingo@kernel.org Cc: Jonathan Cameron Jonathan.Cameron@huawei.com Cc: Joonsoo Kim iamjoonsoo.kim@lge.com Cc: Jun Yao yaojun8558363@gmail.com Cc: Mark Rutland mark.rutland@arm.com Cc: Mike Rapoport rppt@linux.vnet.ibm.com Cc: Oscar Salvador osalvador@suse.de Cc: Robin Murphy robin.murphy@arm.com Cc: Wei Yang richard.weiyang@gmail.com Cc: Will Deacon will.deacon@arm.com Cc: Yu Zhao yuzhao@google.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: David Hildenbrand david@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 950a9e0a4548..778781e5f22e 100644 --- a/arch/ia64/mm/init.c +++ b/arch/ia64/mm/init.c @@ -661,7 +661,6 @@ int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap, return ret; }

-#ifdef CONFIG_MEMORY_HOTREMOVE void arch_remove_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap) { @@ -673,4 +672,3 @@ 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 ab79f2831f9c..84c6d37638a7 100644 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -139,7 +139,6 @@ int __ref arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altm return __add_pages(nid, start_pfn, nr_pages, altmap, want_memblock); }

-#ifdef CONFIG_MEMORY_HOTREMOVE void __ref arch_remove_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap) { @@ -172,7 +171,6 @@ void __ref arch_remove_memory(int nid, u64 start, u64 size, resize_hpt_for_hotplug(memblock_phys_mem_size()); } #endif -#endif /* CONFIG_MEMORY_HOTPLUG */

/* * walk_memory_resource() needs to make sure there is no holes in a given diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index fc761001fa94..e0b0788cfecb 100644 --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -239,7 +239,6 @@ int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap, return rc; }

-#ifdef CONFIG_MEMORY_HOTREMOVE void arch_remove_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap) { @@ -251,5 +250,4 @@ 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 59ae5d7dc081..0da784ac0e34 100644 --- a/arch/sh/mm/init.c +++ b/arch/sh/mm/init.c @@ -443,7 +443,6 @@ 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) { @@ -454,5 +453,4 @@ 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 c6a50a0f240b..64f54f77052b 100644 --- a/arch/x86/mm/init_32.c +++ b/arch/x86/mm/init_32.c @@ -860,7 +860,6 @@ int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap, return __add_pages(nid, start_pfn, nr_pages, altmap, want_memblock); }

-#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;

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index b9e15f25b921..50df7ca142f9 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -1132,7 +1132,6 @@ 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) { @@ -1157,7 +1156,6 @@ 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 5b9950d982dc..9a5f81dc32c5 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -737,7 +737,6 @@ int hotplug_memory_register(int nid, struct mem_section *section) return ret; }

-#ifdef CONFIG_MEMORY_HOTREMOVE static void unregister_memory(struct memory_block *memory) { @@ -776,7 +775,6 @@ 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 04c40da0228a..5ac58325e8fc 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -108,12 +108,10 @@ 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 */

/* reasonably generic interface to expand the physical pages */ extern int __add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages, diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 7905e3275289..6b5ce0bd907f 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -315,7 +315,6 @@ 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, @@ -542,7 +541,6 @@ 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 f52e8c328761..6f624ce9252e 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -576,7 +576,6 @@ 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; @@ -584,7 +583,6 @@ 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) { @@ -623,7 +621,6 @@ 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; @@ -653,7 +650,6 @@ static void free_map_bootmem(struct page *memmap) put_page_bootmem(page); } } -#endif /* CONFIG_MEMORY_HOTREMOVE */ #endif /* CONFIG_SPARSEMEM_VMEMMAP */

/* @@ -712,7 +708,6 @@ 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) { @@ -780,5 +775,4 @@ 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 */

commit db051a0dac13db24d58470d75cee0ce7c6b031a1 upstream.

Only memory to be added to the buddy and to be onlined/offlined by user space using /sys/devices/system/memory/... needs (and should have!) memory block devices.

Factor out creation of memory block devices. Create all devices after arch_add_memory() succeeded. We can later drop the want_memblock parameter, because it is now effectively stale.

Only after memory block devices have been added, memory can be onlined by user space. This implies, that memory is not visible to user space at all before arch_add_memory() succeeded.

While at it - use WARN_ON_ONCE instead of BUG_ON in moved unregister_memory() - introduce find_memory_block_by_id() to search via block id - Use find_memory_block_by_id() in init_memory_block() to catch duplicates

Link: http://lkml.kernel.org/r/20190527111152.16324-8-david@redhat.com Signed-off-by: David Hildenbrand david@redhat.com Reviewed-by: Pavel Tatashin pasha.tatashin@soleen.com Acked-by: Michal Hocko mhocko@suse.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: "Rafael J. Wysocki" rafael@kernel.org Cc: David Hildenbrand david@redhat.com Cc: "mike.travis@hpe.com" mike.travis@hpe.com Cc: Ingo Molnar mingo@kernel.org Cc: Andrew Banman andrew.banman@hpe.com Cc: Oscar Salvador osalvador@suse.de Cc: Qian Cai cai@lca.pw Cc: Wei Yang richard.weiyang@gmail.com Cc: Arun KS arunks@codeaurora.org Cc: Mathieu Malaterre malat@debian.org Cc: Alex Deucher alexander.deucher@amd.com Cc: Andy Lutomirski luto@kernel.org Cc: Anshuman Khandual anshuman.khandual@arm.com Cc: Ard Biesheuvel ard.biesheuvel@linaro.org Cc: Baoquan He bhe@redhat.com Cc: Benjamin Herrenschmidt benh@kernel.crashing.org Cc: Borislav Petkov bp@alien8.de Cc: Catalin Marinas catalin.marinas@arm.com Cc: Chintan Pandya cpandya@codeaurora.org Cc: Christophe Leroy christophe.leroy@c-s.fr Cc: Chris Wilson chris@chris-wilson.co.uk Cc: Dan Williams dan.j.williams@intel.com Cc: Dave Hansen dave.hansen@linux.intel.com Cc: "David S. Miller" davem@davemloft.net Cc: Fenghua Yu fenghua.yu@intel.com Cc: Heiko Carstens heiko.carstens@de.ibm.com Cc: "H. Peter Anvin" hpa@zytor.com Cc: Jonathan Cameron Jonathan.Cameron@huawei.com Cc: Joonsoo Kim iamjoonsoo.kim@lge.com Cc: Jun Yao yaojun8558363@gmail.com Cc: "Kirill A. Shutemov" kirill.shutemov@linux.intel.com Cc: Logan Gunthorpe logang@deltatee.com Cc: Mark Brown broonie@kernel.org Cc: Mark Rutland mark.rutland@arm.com Cc: Masahiro Yamada yamada.masahiro@socionext.com Cc: Michael Ellerman mpe@ellerman.id.au Cc: Mike Rapoport rppt@linux.vnet.ibm.com Cc: Nicholas Piggin npiggin@gmail.com Cc: Oscar Salvador osalvador@suse.com Cc: Paul Mackerras paulus@samba.org Cc: Peter Zijlstra peterz@infradead.org Cc: Rich Felker dalias@libc.org Cc: Rob Herring robh@kernel.org Cc: Robin Murphy robin.murphy@arm.com Cc: Thomas Gleixner tglx@linutronix.de Cc: Tony Luck tony.luck@intel.com Cc: Vasily Gorbik gor@linux.ibm.com Cc: Will Deacon will.deacon@arm.com Cc: Yoshinori Sato ysato@users.sourceforge.jp Cc: Yu Zhao yuzhao@google.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: David Hildenbrand david@redhat.com --- drivers/base/memory.c | 82 +++++++++++++++++++++++++++--------------- include/linux/memory.h | 2 +- mm/memory_hotplug.c | 15 ++++---- 3 files changed, 63 insertions(+), 36 deletions(-)

diff --git a/drivers/base/memory.c b/drivers/base/memory.c index f9818d75ac43..b89b9c3efa59 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -39,6 +39,11 @@ static inline int base_memory_block_id(int section_nr) return section_nr / sections_per_block; }

+static inline int pfn_to_block_id(unsigned long pfn) +{ + return base_memory_block_id(pfn_to_section_nr(pfn)); +} + static int memory_subsys_online(struct device *dev); static int memory_subsys_offline(struct device *dev);

@@ -591,10 +596,9 @@ int __weak arch_get_memory_phys_device(unsigned long start_pfn) * A reference for the returned object is held and the reference for the * hinted object is released. */ -struct memory_block *find_memory_block_hinted(struct mem_section *section, - struct memory_block *hint) +static struct memory_block *find_memory_block_by_id(int block_id, + struct memory_block *hint) { - int block_id = base_memory_block_id(__section_nr(section)); struct device *hintdev = hint ? &hint->dev : NULL; struct device *dev;

@@ -606,6 +610,14 @@ struct memory_block *find_memory_block_hinted(struct mem_section *section, return to_memory_block(dev); }

+struct memory_block *find_memory_block_hinted(struct mem_section *section, + struct memory_block *hint) +{ + int block_id = base_memory_block_id(__section_nr(section)); + + return find_memory_block_by_id(block_id, hint); +} + /* * For now, we have a linear search to go find the appropriate * memory_block corresponding to a particular phys_index. If @@ -667,6 +679,11 @@ static int init_memory_block(struct memory_block **memory, int block_id, unsigned long start_pfn; int ret = 0;

+ mem = find_memory_block_by_id(block_id, NULL); + if (mem) { + put_device(&mem->dev); + return -EEXIST; + } mem = kzalloc(sizeof(*mem), GFP_KERNEL); if (!mem) return -ENOMEM; @@ -704,44 +721,53 @@ static int add_memory_block(int base_section_nr) return 0; }

+static void unregister_memory(struct memory_block *memory) +{ + if (WARN_ON_ONCE(memory->dev.bus != &memory_subsys)) + return; + + /* drop the ref. we got via find_memory_block() */ + put_device(&memory->dev); + device_unregister(&memory->dev); +} + /* - * need an interface for the VM to add new memory regions, - * but without onlining it. + * Create memory block devices for the given memory area. Start and size + * have to be aligned to memory block granularity. Memory block devices + * will be initialized as offline. */ -int hotplug_memory_register(int nid, struct mem_section *section) +int create_memory_block_devices(unsigned long start, unsigned long size) { - int block_id = base_memory_block_id(__section_nr(section)); - int ret = 0; + const int start_block_id = pfn_to_block_id(PFN_DOWN(start)); + int end_block_id = pfn_to_block_id(PFN_DOWN(start + size)); struct memory_block *mem; + unsigned long block_id; + int ret = 0;

- mutex_lock(&mem_sysfs_mutex); + if (WARN_ON_ONCE(!IS_ALIGNED(start, memory_block_size_bytes()) || + !IS_ALIGNED(size, memory_block_size_bytes()))) + return -EINVAL;

- mem = find_memory_block(section); - if (mem) { - mem->section_count++; - put_device(&mem->dev); - } else { + mutex_lock(&mem_sysfs_mutex); + for (block_id = start_block_id; block_id != end_block_id; block_id++) { ret = init_memory_block(&mem, block_id, MEM_OFFLINE); if (ret) - goto out; - mem->section_count++; + break; + mem->section_count = sections_per_block; + } + if (ret) { + end_block_id = block_id; + for (block_id = start_block_id; block_id != end_block_id; + block_id++) { + mem = find_memory_block_by_id(block_id, NULL); + mem->section_count = 0; + unregister_memory(mem); + } } - -out: mutex_unlock(&mem_sysfs_mutex); return ret; }

-static void -unregister_memory(struct memory_block *memory) -{ - BUG_ON(memory->dev.bus != &memory_subsys); - - /* drop the ref. we got via find_memory_block() */ - put_device(&memory->dev); - device_unregister(&memory->dev); -} - void unregister_memory_section(struct mem_section *section) { struct memory_block *mem; diff --git a/include/linux/memory.h b/include/linux/memory.h index 474c7c60c8f2..db3e8567f900 100644 --- a/include/linux/memory.h +++ b/include/linux/memory.h @@ -111,7 +111,7 @@ extern int register_memory_notifier(struct notifier_block *nb); 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); +int create_memory_block_devices(unsigned long start, unsigned long size); extern void unregister_memory_section(struct mem_section *); extern int memory_dev_init(void); extern int memory_notify(unsigned long val, void *v); diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 6b5ce0bd907f..414771114685 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -256,13 +256,7 @@ static int __meminit __add_section(int nid, unsigned long phys_start_pfn, return -EEXIST;

ret = sparse_add_one_section(nid, phys_start_pfn, altmap); - if (ret < 0) - return ret; - - if (!want_memblock) - return 0; - - return hotplug_memory_register(nid, __pfn_to_section(phys_start_pfn)); + return ret < 0 ? ret : 0; }

/* @@ -1096,6 +1090,13 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online) if (ret < 0) goto error;

+ /* create memory block devices after memory was added */ + ret = create_memory_block_devices(start, size); + if (ret) { + arch_remove_memory(nid, start, size, NULL); + goto error; + } + if (new_node) { /* If sysfs file of new node can't be created, cpu on the node * can't be hot-added. There is no rollback way now.

commit a31b264c2b415b29660da0bc2ba291a98629ce51 upstream.

We really don't want anything during memory hotunplug to fail. We always pass a valid memory block device, that check can go. Avoid allocating memory and eventually failing. As we are always called under lock, we can use a static piece of memory. This avoids having to put the structure onto the stack, having to guess about the stack size of callers.

Patch inspired by a patch from Oscar Salvador.

In the future, there might be no need to iterate over nodes at all. mem->nid should tell us exactly what to remove. Memory block devices with mixed nodes (added during boot) should properly fenced off and never removed.

Link: http://lkml.kernel.org/r/20190527111152.16324-11-david@redhat.com Signed-off-by: David Hildenbrand david@redhat.com Reviewed-by: Wei Yang richardw.yang@linux.intel.com Reviewed-by: Oscar Salvador osalvador@suse.de Acked-by: Michal Hocko mhocko@suse.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: "Rafael J. Wysocki" rafael@kernel.org Cc: Alex Deucher alexander.deucher@amd.com Cc: "David S. Miller" davem@davemloft.net Cc: Mark Brown broonie@kernel.org Cc: Chris Wilson chris@chris-wilson.co.uk Cc: David Hildenbrand david@redhat.com Cc: Jonathan Cameron Jonathan.Cameron@huawei.com Cc: Andrew Banman andrew.banman@hpe.com Cc: Andy Lutomirski luto@kernel.org Cc: Anshuman Khandual anshuman.khandual@arm.com Cc: Ard Biesheuvel ard.biesheuvel@linaro.org Cc: Arun KS arunks@codeaurora.org Cc: Baoquan He bhe@redhat.com Cc: Benjamin Herrenschmidt benh@kernel.crashing.org Cc: Borislav Petkov bp@alien8.de Cc: Catalin Marinas catalin.marinas@arm.com Cc: Chintan Pandya cpandya@codeaurora.org Cc: Christophe Leroy christophe.leroy@c-s.fr Cc: Dan Williams dan.j.williams@intel.com Cc: Dave Hansen dave.hansen@linux.intel.com Cc: Fenghua Yu fenghua.yu@intel.com Cc: Heiko Carstens heiko.carstens@de.ibm.com Cc: "H. Peter Anvin" hpa@zytor.com Cc: Ingo Molnar mingo@kernel.org Cc: Joonsoo Kim iamjoonsoo.kim@lge.com Cc: Jun Yao yaojun8558363@gmail.com Cc: "Kirill A. Shutemov" kirill.shutemov@linux.intel.com Cc: Logan Gunthorpe logang@deltatee.com Cc: Mark Rutland mark.rutland@arm.com Cc: Masahiro Yamada yamada.masahiro@socionext.com Cc: Mathieu Malaterre malat@debian.org Cc: Michael Ellerman mpe@ellerman.id.au Cc: Mike Rapoport rppt@linux.vnet.ibm.com Cc: "mike.travis@hpe.com" mike.travis@hpe.com Cc: Nicholas Piggin npiggin@gmail.com Cc: Paul Mackerras paulus@samba.org Cc: Pavel Tatashin pasha.tatashin@soleen.com Cc: Peter Zijlstra peterz@infradead.org Cc: Qian Cai cai@lca.pw Cc: Rich Felker dalias@libc.org Cc: Rob Herring robh@kernel.org Cc: Robin Murphy robin.murphy@arm.com Cc: Thomas Gleixner tglx@linutronix.de Cc: Tony Luck tony.luck@intel.com Cc: Vasily Gorbik gor@linux.ibm.com Cc: Will Deacon will.deacon@arm.com Cc: Yoshinori Sato ysato@users.sourceforge.jp Cc: Yu Zhao yuzhao@google.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: David Hildenbrand david@redhat.com --- drivers/base/node.c | 18 +++++------------- include/linux/node.h | 5 ++--- 2 files changed, 7 insertions(+), 16 deletions(-)

diff --git a/drivers/base/node.c b/drivers/base/node.c index 1211794d658c..bdff237f4167 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -455,20 +455,14 @@ int register_mem_sect_under_node(struct memory_block *mem_blk, void *arg)

/* * Unregister memory block device under all nodes that it spans. + * Has to be called with mem_sysfs_mutex held (due to unlinked_nodes). */ -int unregister_memory_block_under_nodes(struct memory_block *mem_blk) +void unregister_memory_block_under_nodes(struct memory_block *mem_blk) { - NODEMASK_ALLOC(nodemask_t, unlinked_nodes, GFP_KERNEL); unsigned long pfn, sect_start_pfn, sect_end_pfn; + static nodemask_t unlinked_nodes;

- if (!mem_blk) { - NODEMASK_FREE(unlinked_nodes); - return -EFAULT; - } - if (!unlinked_nodes) - return -ENOMEM; - nodes_clear(*unlinked_nodes); - + nodes_clear(unlinked_nodes); sect_start_pfn = section_nr_to_pfn(mem_blk->start_section_nr); sect_end_pfn = section_nr_to_pfn(mem_blk->end_section_nr); for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) { @@ -479,15 +473,13 @@ int unregister_memory_block_under_nodes(struct memory_block *mem_blk) continue; if (!node_online(nid)) continue; - if (node_test_and_set(nid, *unlinked_nodes)) + if (node_test_and_set(nid, unlinked_nodes)) continue; sysfs_remove_link(&node_devices[nid]->dev.kobj, kobject_name(&mem_blk->dev.kobj)); sysfs_remove_link(&mem_blk->dev.kobj, kobject_name(&node_devices[nid]->dev.kobj)); } - NODEMASK_FREE(unlinked_nodes); - return 0; }

int link_mem_sections(int nid, unsigned long start_pfn, unsigned long end_pfn) diff --git a/include/linux/node.h b/include/linux/node.h index 9a6db437f2d1..708939bae9aa 100644 --- a/include/linux/node.h +++ b/include/linux/node.h @@ -72,7 +72,7 @@ extern int register_cpu_under_node(unsigned int cpu, unsigned int nid); extern int unregister_cpu_under_node(unsigned int cpu, unsigned int nid); extern int register_mem_sect_under_node(struct memory_block *mem_blk, void *arg); -extern int unregister_memory_block_under_nodes(struct memory_block *mem_blk); +extern void unregister_memory_block_under_nodes(struct memory_block *mem_blk);

#ifdef CONFIG_HUGETLBFS extern void register_hugetlbfs_with_node(node_registration_func_t doregister, @@ -104,9 +104,8 @@ static inline int register_mem_sect_under_node(struct memory_block *mem_blk, { return 0; } -static inline int unregister_memory_block_under_nodes(struct memory_block *mem_blk) +static inline void unregister_memory_block_under_nodes(struct memory_block *mem_blk) { - return 0; }

static inline void register_hugetlbfs_with_node(node_registration_func_t reg,

From: Dan Williams dan.j.williams@intel.com

commit 96da4350000973ef9310a10d077d65bbc017f093 upstream.

-- snip --

Minor conflict, keep the altmap check.

-- snip --

The zone type check was a leftover from the cleanup that plumbed altmap through the memory hotplug path, i.e. commit da024512a1fa "mm: pass the vmem_altmap to arch_remove_memory and __remove_pages".

Link: http://lkml.kernel.org/r/156092352642.979959.6664333788149363039.stgit@dwill... Signed-off-by: Dan Williams dan.j.williams@intel.com Reviewed-by: David Hildenbrand david@redhat.com Reviewed-by: Oscar Salvador osalvador@suse.de Tested-by: Aneesh Kumar K.V aneesh.kumar@linux.ibm.com [ppc64] Cc: Michal Hocko mhocko@suse.com Cc: Logan Gunthorpe logang@deltatee.com Cc: Pavel Tatashin pasha.tatashin@soleen.com Cc: Jane Chu jane.chu@oracle.com Cc: Jeff Moyer jmoyer@redhat.com Cc: Jérôme Glisse jglisse@redhat.com Cc: Jonathan Corbet corbet@lwn.net Cc: Mike Rapoport rppt@linux.ibm.com Cc: Toshi Kani toshi.kani@hpe.com Cc: Vlastimil Babka vbabka@suse.cz Cc: Wei Yang richardw.yang@linux.intel.com Cc: Jason Gunthorpe jgg@mellanox.com Cc: Christoph Hellwig hch@lst.de Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: David Hildenbrand david@redhat.com --- mm/memory_hotplug.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 74cfa2fbe88e..888fcbdf97cf 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -507,11 +507,8 @@ void __remove_pages(struct zone *zone, unsigned long phys_start_pfn, unsigned long map_offset = 0; int sections_to_remove;

- /* In the ZONE_DEVICE case device driver owns the memory region */ - if (is_dev_zone(zone)) { - if (altmap) - map_offset = vmem_altmap_offset(altmap); - } + if (altmap) + map_offset = vmem_altmap_offset(altmap);

clear_zone_contiguous(zone);

From: "Aneesh Kumar K.V" aneesh.kumar@linux.ibm.com

commit 77e080e7680e1e615587352f70c87b9e98126d03 upstream.

-- snip --

- Missing mm/hmm.c and kernel/memremap.c unification. -- hmm code does not need fixes (no altmap) - Missing 7cc7867fb061 ("mm/devm_memremap_pages: enable sub-section remap")

-- snip --

Patch series "mm/memory_hotplug: Shrink zones before removing memory", v6.

This series fixes the access of uninitialized memmaps when shrinking zones/nodes and when removing memory. Also, it contains all fixes for crashes that can be triggered when removing certain namespace using memunmap_pages() - ZONE_DEVICE, reported by Aneesh.

We stop trying to shrink ZONE_DEVICE, as it's buggy, fixing it would be more involved (we don't have SECTION_IS_ONLINE as an indicator), and shrinking is only of limited use (set_zone_contiguous() cannot detect the ZONE_DEVICE as contiguous).

We continue shrinking !ZONE_DEVICE zones, however, I reduced the amount of code to a minimum. Shrinking is especially necessary to keep zone->contiguous set where possible, especially, on memory unplug of DIMMs at zone boundaries.

--------------------------------------------------------------------------

Zones are now properly shrunk when offlining memory blocks or when onlining failed. This allows to properly shrink zones on memory unplug even if the separate memory blocks of a DIMM were onlined to different zones or re-onlined to a different zone after offlining.

Example:

:/# cat /proc/zoneinfo Node 1, zone Movable spanned 0 present 0 managed 0 :/# echo "online_movable" > /sys/devices/system/memory/memory41/state :/# echo "online_movable" > /sys/devices/system/memory/memory43/state :/# cat /proc/zoneinfo Node 1, zone Movable spanned 98304 present 65536 managed 65536 :/# echo 0 > /sys/devices/system/memory/memory43/online :/# cat /proc/zoneinfo Node 1, zone Movable spanned 32768 present 32768 managed 32768 :/# echo 0 > /sys/devices/system/memory/memory41/online :/# cat /proc/zoneinfo Node 1, zone Movable spanned 0 present 0 managed 0

This patch (of 10):

With an altmap, the memmap falling into the reserved altmap space are not initialized and, therefore, contain a garbage NID and a garbage zone. Make sure to read the NID/zone from a memmap that was initialized.

This fixes a kernel crash that is observed when destroying a namespace:

kernel BUG at include/linux/mm.h:1107! cpu 0x1: Vector: 700 (Program Check) at [c000000274087890] pc: c0000000004b9728: memunmap_pages+0x238/0x340 lr: c0000000004b9724: memunmap_pages+0x234/0x340 ... pid = 3669, comm = ndctl kernel BUG at include/linux/mm.h:1107! devm_action_release+0x30/0x50 release_nodes+0x268/0x2d0 device_release_driver_internal+0x174/0x240 unbind_store+0x13c/0x190 drv_attr_store+0x44/0x60 sysfs_kf_write+0x70/0xa0 kernfs_fop_write+0x1ac/0x290 __vfs_write+0x3c/0x70 vfs_write+0xe4/0x200 ksys_write+0x7c/0x140 system_call+0x5c/0x68

The "page_zone(pfn_to_page(pfn)" was introduced by 69324b8f4833 ("mm, devm_memremap_pages: add MEMORY_DEVICE_PRIVATE support"), however, I think we will never have driver reserved memory with MEMORY_DEVICE_PRIVATE (no altmap AFAIKS).

[david@redhat.com: minimze code changes, rephrase description] Link: http://lkml.kernel.org/r/20191006085646.5768-2-david@redhat.com Fixes: 2c2a5af6fed2 ("mm, memory_hotplug: add nid parameter to arch_remove_memory") Signed-off-by: Aneesh Kumar K.V aneesh.kumar@linux.ibm.com Signed-off-by: David Hildenbrand david@redhat.com Cc: Dan Williams dan.j.williams@intel.com Cc: Jason Gunthorpe jgg@ziepe.ca Cc: Logan Gunthorpe logang@deltatee.com Cc: Ira Weiny ira.weiny@intel.com Cc: Damian Tometzki damian.tometzki@gmail.com Cc: Alexander Duyck alexander.h.duyck@linux.intel.com Cc: Alexander Potapenko glider@google.com Cc: Andy Lutomirski luto@kernel.org Cc: Anshuman Khandual anshuman.khandual@arm.com Cc: Benjamin Herrenschmidt benh@kernel.crashing.org Cc: Borislav Petkov bp@alien8.de Cc: Catalin Marinas catalin.marinas@arm.com Cc: Christian Borntraeger borntraeger@de.ibm.com Cc: Christophe Leroy christophe.leroy@c-s.fr Cc: Dave Hansen dave.hansen@linux.intel.com Cc: Fenghua Yu fenghua.yu@intel.com Cc: Gerald Schaefer gerald.schaefer@de.ibm.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Halil Pasic pasic@linux.ibm.com Cc: Heiko Carstens heiko.carstens@de.ibm.com Cc: "H. Peter Anvin" hpa@zytor.com Cc: Ingo Molnar mingo@redhat.com Cc: Jun Yao yaojun8558363@gmail.com Cc: Mark Rutland mark.rutland@arm.com Cc: Masahiro Yamada yamada.masahiro@socionext.com Cc: "Matthew Wilcox (Oracle)" willy@infradead.org Cc: Mel Gorman mgorman@techsingularity.net Cc: Michael Ellerman mpe@ellerman.id.au Cc: Michal Hocko mhocko@suse.com Cc: Mike Rapoport rppt@linux.ibm.com Cc: Oscar Salvador osalvador@suse.de Cc: Pankaj Gupta pagupta@redhat.com Cc: Paul Mackerras paulus@samba.org Cc: Pavel Tatashin pasha.tatashin@soleen.com Cc: Pavel Tatashin pavel.tatashin@microsoft.com Cc: Peter Zijlstra peterz@infradead.org Cc: Qian Cai cai@lca.pw Cc: Rich Felker dalias@libc.org Cc: Robin Murphy robin.murphy@arm.com Cc: Steve Capper steve.capper@arm.com Cc: Thomas Gleixner tglx@linutronix.de Cc: Tom Lendacky thomas.lendacky@amd.com Cc: Tony Luck tony.luck@intel.com Cc: Vasily Gorbik gor@linux.ibm.com Cc: Vlastimil Babka vbabka@suse.cz Cc: Wei Yang richard.weiyang@gmail.com Cc: Wei Yang richardw.yang@linux.intel.com Cc: Will Deacon will@kernel.org Cc: Yoshinori Sato ysato@users.sourceforge.jp Cc: Yu Zhao yuzhao@google.com Cc: stable@vger.kernel.org [5.0+] Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: David Hildenbrand david@redhat.com --- kernel/memremap.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/kernel/memremap.c b/kernel/memremap.c index 2ee2e672d5fc..1ec1f8fd97f5 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -120,6 +120,7 @@ static void devm_memremap_pages_release(void *data) struct device *dev = pgmap->dev; struct resource *res = &pgmap->res; resource_size_t align_start, align_size; + struct page *first_page; unsigned long pfn; int nid;

@@ -132,13 +133,16 @@ static void devm_memremap_pages_release(void *data) align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE) - align_start;

- nid = page_to_nid(pfn_to_page(align_start >> PAGE_SHIFT)); + /* make sure to access a memmap that was actually initialized */ + first_page = pfn_to_page(pfn_first(pgmap)); + + nid = page_to_nid(first_page);

mem_hotplug_begin(); if (pgmap->type == MEMORY_DEVICE_PRIVATE) { pfn = align_start >> PAGE_SHIFT; - __remove_pages(page_zone(pfn_to_page(pfn)), pfn, - align_size >> PAGE_SHIFT, NULL); + __remove_pages(page_zone(first_page), pfn, + align_size >> PAGE_SHIFT, NULL); } else { arch_remove_memory(nid, align_start, align_size, pgmap->altmap_valid ? &pgmap->altmap : NULL);

commit feee6b2989165631b17ac6d4ccdbf6759254e85a upstream.

-- snip --

- Missing arm64 hot(un)plug support - Missing some vmem_altmap_offset() cleanups - Missing sub-section hotadd support - Missing unification of mm/hmm.c and kernel/memremap.c

-- snip --

We currently try to shrink a single zone when removing memory. We use the zone of the first page of the memory we are removing. If that memmap was never initialized (e.g., memory was never onlined), we will read garbage and can trigger kernel BUGs (due to a stale pointer):

BUG: unable to handle page fault for address: 000000000000353d #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP PTI CPU: 1 PID: 7 Comm: kworker/u8:0 Not tainted 5.3.0-rc5-next-20190820+ #317 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.4 Workqueue: kacpi_hotplug acpi_hotplug_work_fn RIP: 0010:clear_zone_contiguous+0x5/0x10 Code: 48 89 c6 48 89 c3 e8 2a fe ff ff 48 85 c0 75 cf 5b 5d c3 c6 85 fd 05 00 00 01 5b 5d c3 0f 1f 840 RSP: 0018:ffffad2400043c98 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000200000000 RCX: 0000000000000000 RDX: 0000000000200000 RSI: 0000000000140000 RDI: 0000000000002f40 RBP: 0000000140000000 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000140000 R13: 0000000000140000 R14: 0000000000002f40 R15: ffff9e3e7aff3680 FS: 0000000000000000(0000) GS:ffff9e3e7bb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000000353d CR3: 0000000058610000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __remove_pages+0x4b/0x640 arch_remove_memory+0x63/0x8d try_remove_memory+0xdb/0x130 __remove_memory+0xa/0x11 acpi_memory_device_remove+0x70/0x100 acpi_bus_trim+0x55/0x90 acpi_device_hotplug+0x227/0x3a0 acpi_hotplug_work_fn+0x1a/0x30 process_one_work+0x221/0x550 worker_thread+0x50/0x3b0 kthread+0x105/0x140 ret_from_fork+0x3a/0x50 Modules linked in: CR2: 000000000000353d

Instead, shrink the zones when offlining memory or when onlining failed. Introduce and use remove_pfn_range_from_zone(() for that. We now properly shrink the zones, even if we have DIMMs whereby

- Some memory blocks fall into no zone (never onlined)

- Some memory blocks fall into multiple zones (offlined+re-onlined)

- Multiple memory blocks that fall into different zones

Drop the zone parameter (with a potential dubious value) from __remove_pages() and __remove_section().

Link: http://lkml.kernel.org/r/20191006085646.5768-6-david@redhat.com Fixes: f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory to zones until online") [visible after d0dc12e86b319] Signed-off-by: David Hildenbrand david@redhat.com Reviewed-by: Oscar Salvador osalvador@suse.de Cc: Michal Hocko mhocko@suse.com Cc: "Matthew Wilcox (Oracle)" willy@infradead.org Cc: "Aneesh Kumar K.V" aneesh.kumar@linux.ibm.com Cc: Pavel Tatashin pasha.tatashin@soleen.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Dan Williams dan.j.williams@intel.com Cc: Logan Gunthorpe logang@deltatee.com Cc: stable@vger.kernel.org [5.0+] Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: David Hildenbrand david@redhat.com --- arch/ia64/mm/init.c | 4 +--- arch/powerpc/mm/mem.c | 11 +---------- arch/s390/mm/init.c | 4 +--- arch/sh/mm/init.c | 4 +--- arch/x86/mm/init_32.c | 4 +--- arch/x86/mm/init_64.c | 8 +------- include/linux/memory_hotplug.h | 7 +++++-- kernel/memremap.c | 3 +-- mm/hmm.c | 4 +--- mm/memory_hotplug.c | 29 ++++++++++++++--------------- 10 files changed, 27 insertions(+), 51 deletions(-)

diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c index 778781e5f22e..79e5cc70f1fd 100644 --- a/arch/ia64/mm/init.c +++ b/arch/ia64/mm/init.c @@ -666,9 +666,7 @@ void arch_remove_memory(int nid, u64 start, u64 size, { 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)); - __remove_pages(zone, start_pfn, nr_pages, altmap); + __remove_pages(start_pfn, nr_pages, altmap); } #endif diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c index 84c6d37638a7..84a012e42a7e 100644 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -144,18 +144,9 @@ void __ref arch_remove_memory(int nid, u64 start, u64 size, { unsigned long start_pfn = start >> PAGE_SHIFT; unsigned long nr_pages = size >> PAGE_SHIFT; - struct page *page; int ret;

- /* - * If we have an altmap then we need to skip over any reserved PFNs - * when querying the zone. - */ - page = pfn_to_page(start_pfn); - if (altmap) - page += vmem_altmap_offset(altmap); - - __remove_pages(page_zone(page), start_pfn, nr_pages, altmap); + __remove_pages(start_pfn, nr_pages, altmap);

/* Remove htab bolted mappings for this section of memory */ start = (unsigned long)__va(start); diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index e0b0788cfecb..379a925d9e82 100644 --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -244,10 +244,8 @@ void arch_remove_memory(int nid, u64 start, u64 size, { 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)); - __remove_pages(zone, start_pfn, nr_pages, altmap); + __remove_pages(start_pfn, nr_pages, altmap); vmem_remove_mapping(start, size); } #endif /* CONFIG_MEMORY_HOTPLUG */ diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c index 0da784ac0e34..47882be91121 100644 --- a/arch/sh/mm/init.c +++ b/arch/sh/mm/init.c @@ -448,9 +448,7 @@ void arch_remove_memory(int nid, u64 start, u64 size, { unsigned long start_pfn = PFN_DOWN(start); unsigned long nr_pages = size >> PAGE_SHIFT; - struct zone *zone;

- zone = page_zone(pfn_to_page(start_pfn)); - __remove_pages(zone, start_pfn, nr_pages, altmap); + __remove_pages(start_pfn, nr_pages, altmap); } #endif /* CONFIG_MEMORY_HOTPLUG */ diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c index 64f54f77052b..79b95910fd9f 100644 --- a/arch/x86/mm/init_32.c +++ b/arch/x86/mm/init_32.c @@ -865,10 +865,8 @@ void arch_remove_memory(int nid, u64 start, u64 size, { 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)); - __remove_pages(zone, start_pfn, nr_pages, altmap); + __remove_pages(start_pfn, nr_pages, altmap); } #endif

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 50df7ca142f9..81e85a8dd300 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -1146,14 +1146,8 @@ void __ref arch_remove_memory(int nid, u64 start, u64 size, { 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;

- /* With altmap the first mapped page is offset from @start */ - if (altmap) - page += vmem_altmap_offset(altmap); - zone = page_zone(page); - __remove_pages(zone, start_pfn, nr_pages, altmap); + __remove_pages(start_pfn, nr_pages, altmap); kernel_physical_mapping_remove(start, start + size); } #endif /* CONFIG_MEMORY_HOTPLUG */ diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 26bda048f8a7..d17d45c41a0b 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -110,8 +110,8 @@ static inline bool movable_node_is_enabled(void)

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); +extern void __remove_pages(unsigned long start_pfn, unsigned long nr_pages, + struct vmem_altmap *altmap);

/* reasonably generic interface to expand the physical pages */ extern int __add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages, @@ -331,6 +331,9 @@ extern int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap, bool want_memblock); extern void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn, unsigned long nr_pages, struct vmem_altmap *altmap); +extern void remove_pfn_range_from_zone(struct zone *zone, + unsigned long start_pfn, + unsigned long nr_pages); extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages); extern bool is_memblock_offlined(struct memory_block *mem); extern int sparse_add_one_section(int nid, unsigned long start_pfn, diff --git a/kernel/memremap.c b/kernel/memremap.c index 1ec1f8fd97f5..331baad8efec 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -141,8 +141,7 @@ static void devm_memremap_pages_release(void *data) mem_hotplug_begin(); if (pgmap->type == MEMORY_DEVICE_PRIVATE) { pfn = align_start >> PAGE_SHIFT; - __remove_pages(page_zone(first_page), pfn, - align_size >> PAGE_SHIFT, NULL); + __remove_pages(pfn, align_size >> PAGE_SHIFT, NULL); } else { arch_remove_memory(nid, align_start, align_size, pgmap->altmap_valid ? &pgmap->altmap : NULL); diff --git a/mm/hmm.c b/mm/hmm.c index ae1f6ad46d30..c482c07bbab7 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -997,7 +997,6 @@ static void hmm_devmem_release(void *data) struct hmm_devmem *devmem = data; struct resource *resource = devmem->resource; unsigned long start_pfn, npages; - struct zone *zone; struct page *page; int nid;

@@ -1006,12 +1005,11 @@ static void hmm_devmem_release(void *data) npages = ALIGN(resource_size(resource), PA_SECTION_SIZE) >> PAGE_SHIFT;

page = pfn_to_page(start_pfn); - zone = page_zone(page); nid = page_to_nid(page);

mem_hotplug_begin(); if (resource->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) - __remove_pages(zone, start_pfn, npages, NULL); + __remove_pages(start_pfn, npages, NULL); else arch_remove_memory(nid, start_pfn << PAGE_SHIFT, npages << PAGE_SHIFT, NULL); diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 7ab34360920b..abc10dcbc9d5 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -449,10 +449,11 @@ static void update_pgdat_span(struct pglist_data *pgdat) pgdat->node_spanned_pages = node_end_pfn - node_start_pfn; }

-static void __remove_zone(struct zone *zone, unsigned long start_pfn) +void __ref remove_pfn_range_from_zone(struct zone *zone, + unsigned long start_pfn, + unsigned long nr_pages) { struct pglist_data *pgdat = zone->zone_pgdat; - int nr_pages = PAGES_PER_SECTION; unsigned long flags;

#ifdef CONFIG_ZONE_DEVICE @@ -465,14 +466,17 @@ static void __remove_zone(struct zone *zone, unsigned long start_pfn) return; #endif

+ clear_zone_contiguous(zone); + pgdat_resize_lock(zone->zone_pgdat, &flags); shrink_zone_span(zone, start_pfn, start_pfn + nr_pages); update_pgdat_span(pgdat); pgdat_resize_unlock(zone->zone_pgdat, &flags); + + set_zone_contiguous(zone); }

-static void __remove_section(struct zone *zone, struct mem_section *ms, - unsigned long map_offset, +static void __remove_section(struct mem_section *ms, unsigned long map_offset, struct vmem_altmap *altmap) { unsigned long start_pfn; @@ -483,14 +487,12 @@ static void __remove_section(struct zone *zone, struct mem_section *ms,

scn_nr = __section_nr(ms); start_pfn = section_nr_to_pfn((unsigned long)scn_nr); - __remove_zone(zone, start_pfn);

sparse_remove_one_section(ms, map_offset, altmap); }

/** - * __remove_pages() - remove sections of pages from a zone - * @zone: zone from which pages need to be removed + * __remove_pages() - remove sections of pages * @phys_start_pfn: starting pageframe (must be aligned to start of a section) * @nr_pages: number of pages to remove (must be multiple of section size) * @altmap: alternative device page map or %NULL if default memmap is used @@ -500,8 +502,8 @@ 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(). */ -void __remove_pages(struct zone *zone, unsigned long phys_start_pfn, - unsigned long nr_pages, struct vmem_altmap *altmap) +void __remove_pages(unsigned long phys_start_pfn, unsigned long nr_pages, + struct vmem_altmap *altmap) { unsigned long i; unsigned long map_offset = 0; @@ -510,8 +512,6 @@ void __remove_pages(struct zone *zone, unsigned long phys_start_pfn, if (altmap) map_offset = vmem_altmap_offset(altmap);

- clear_zone_contiguous(zone); - /* * We can only remove entire sections */ @@ -523,12 +523,9 @@ void __remove_pages(struct zone *zone, unsigned long phys_start_pfn, unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION;

cond_resched(); - __remove_section(zone, __pfn_to_section(pfn), map_offset, - altmap); + __remove_section(__pfn_to_section(pfn), map_offset, altmap); map_offset = 0; } - - set_zone_contiguous(zone); }

int set_online_page_callback(online_page_callback_t callback) @@ -898,6 +895,7 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ (unsigned long long) pfn << PAGE_SHIFT, (((unsigned long long) pfn + nr_pages) << PAGE_SHIFT) - 1); memory_notify(MEM_CANCEL_ONLINE, &arg); + remove_pfn_range_from_zone(zone, pfn, nr_pages); mem_hotplug_done(); return ret; } @@ -1682,6 +1680,7 @@ static int __ref __offline_pages(unsigned long start_pfn, writeback_set_ratelimit();

memory_notify(MEM_OFFLINE, &arg); + remove_pfn_range_from_zone(zone, start_pfn, nr_pages); mem_hotplug_done(); return 0;