From 4c4b7f9ba9486c565aead99a198ceeef73ae81f6 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 18 Jul 2019 15:57:06 -0700 Subject: mm/memory_hotplug: remove memory block devices before arch_remove_memory() Let's factor out removing of memory block devices, which is only necessary for memory added via add_memory() and friends that created memory block devices. Remove the devices before calling arch_remove_memory(). This finishes factoring out memory block device handling from arch_add_memory() and arch_remove_memory(). Link: http://lkml.kernel.org/r/20190527111152.16324-10-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Dan Williams Acked-by: Michal Hocko Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: David Hildenbrand Cc: "mike.travis@hpe.com" Cc: Andrew Banman Cc: Ingo Molnar Cc: Alex Deucher Cc: "David S. Miller" Cc: Mark Brown Cc: Chris Wilson Cc: Oscar Salvador Cc: Jonathan Cameron Cc: Arun KS Cc: Mathieu Malaterre Cc: Andy Lutomirski Cc: Anshuman Khandual Cc: Ard Biesheuvel Cc: Baoquan He Cc: Benjamin Herrenschmidt Cc: Borislav Petkov Cc: Catalin Marinas Cc: Chintan Pandya Cc: Christophe Leroy Cc: Dave Hansen Cc: Fenghua Yu Cc: Heiko Carstens Cc: "H. Peter Anvin" Cc: Joonsoo Kim Cc: Jun Yao Cc: "Kirill A. Shutemov" Cc: Logan Gunthorpe Cc: Mark Rutland Cc: Masahiro Yamada Cc: Michael Ellerman Cc: Mike Rapoport Cc: Nicholas Piggin Cc: Oscar Salvador Cc: Paul Mackerras Cc: Pavel Tatashin Cc: Peter Zijlstra Cc: Qian Cai Cc: Rich Felker Cc: Rob Herring Cc: Robin Murphy Cc: Thomas Gleixner Cc: Tony Luck Cc: Vasily Gorbik Cc: Wei Yang Cc: Will Deacon Cc: Yoshinori Sato Cc: Yu Zhao Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/base/node.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) (limited to 'drivers/base/node.c') diff --git a/drivers/base/node.c b/drivers/base/node.c index aa878fbcf705..0b0f38c2c7cd 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -802,9 +802,10 @@ int register_mem_sect_under_node(struct memory_block *mem_blk, void *arg) return 0; } -/* unregister memory section under all nodes that it spans */ -int unregister_mem_sect_under_nodes(struct memory_block *mem_blk, - unsigned long phys_index) +/* + * Unregister memory block device under all nodes that it spans. + */ +int 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; @@ -817,8 +818,8 @@ int unregister_mem_sect_under_nodes(struct memory_block *mem_blk, return -ENOMEM; nodes_clear(*unlinked_nodes); - sect_start_pfn = section_nr_to_pfn(phys_index); - sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1; + 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++) { int nid; -- cgit v1.2.3 From a31b264c2b415b29660da0bc2ba291a98629ce51 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 18 Jul 2019 15:57:12 -0700 Subject: mm/memory_hotplug: make unregister_memory_block_under_nodes() never fail 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 Reviewed-by: Wei Yang Reviewed-by: Oscar Salvador Acked-by: Michal Hocko Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: Alex Deucher Cc: "David S. Miller" Cc: Mark Brown Cc: Chris Wilson Cc: David Hildenbrand Cc: Jonathan Cameron Cc: Andrew Banman Cc: Andy Lutomirski Cc: Anshuman Khandual Cc: Ard Biesheuvel Cc: Arun KS Cc: Baoquan He Cc: Benjamin Herrenschmidt Cc: Borislav Petkov Cc: Catalin Marinas Cc: Chintan Pandya Cc: Christophe Leroy Cc: Dan Williams Cc: Dave Hansen Cc: Fenghua Yu Cc: Heiko Carstens Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Joonsoo Kim Cc: Jun Yao Cc: "Kirill A. Shutemov" Cc: Logan Gunthorpe Cc: Mark Rutland Cc: Masahiro Yamada Cc: Mathieu Malaterre Cc: Michael Ellerman Cc: Mike Rapoport Cc: "mike.travis@hpe.com" Cc: Nicholas Piggin Cc: Paul Mackerras Cc: Pavel Tatashin Cc: Peter Zijlstra Cc: Qian Cai Cc: Rich Felker Cc: Rob Herring Cc: Robin Murphy Cc: Thomas Gleixner Cc: Tony Luck Cc: Vasily Gorbik Cc: Will Deacon Cc: Yoshinori Sato Cc: Yu Zhao Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/base/node.c | 18 +++++------------- 1 file changed, 5 insertions(+), 13 deletions(-) (limited to 'drivers/base/node.c') diff --git a/drivers/base/node.c b/drivers/base/node.c index 0b0f38c2c7cd..beec80649b33 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -804,20 +804,14 @@ 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++) { @@ -828,15 +822,13 @@ 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) -- cgit v1.2.3 From 8d595c4c0f768f19db043d378b22e98405f9fd47 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 18 Jul 2019 15:57:43 -0700 Subject: mm: make register_mem_sect_under_node() static It is only used internally. Link: http://lkml.kernel.org/r/20190614100114.311-4-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Andrew Morton Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: Keith Busch Cc: Oscar Salvador Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/base/node.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/base/node.c') diff --git a/drivers/base/node.c b/drivers/base/node.c index beec80649b33..27391f1e8f60 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -753,7 +753,8 @@ static int __ref get_nid_for_pfn(unsigned long pfn) } /* register memory section under specified node if it spans that node */ -int register_mem_sect_under_node(struct memory_block *mem_blk, void *arg) +static int register_mem_sect_under_node(struct memory_block *mem_blk, + void *arg) { int ret, nid = *(int *)arg; unsigned long pfn, sect_start_pfn, sect_end_pfn; -- cgit v1.2.3 From fbcf73ce65827c3d8935f38b832a43153a0c78d1 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 18 Jul 2019 15:57:46 -0700 Subject: mm/memory_hotplug: rename walk_memory_range() and pass start+size instead of pfns walk_memory_range() was once used to iterate over sections. Now, it iterates over memory blocks. Rename the function, fixup the documentation. Also, pass start+size instead of PFNs, which is what most callers already have at hand. (we'll rework link_mem_sections() most probably soon) Follow-up patches will rework, simplify, and move walk_memory_blocks() to drivers/base/memory.c. Note: walk_memory_blocks() only works correctly right now if the start_pfn is aligned to a section start. This is the case right now, but we'll generalize the function in a follow up patch so the semantics match the documentation. [akpm@linux-foundation.org: remove unused variable] Link: http://lkml.kernel.org/r/20190614100114.311-5-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Andrew Morton Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: "Rafael J. Wysocki" Cc: Len Brown Cc: Greg Kroah-Hartman Cc: David Hildenbrand Cc: Rashmica Gupta Cc: Pavel Tatashin Cc: Anshuman Khandual Cc: Michael Neuling Cc: Thomas Gleixner Cc: Oscar Salvador Cc: Michal Hocko Cc: Wei Yang Cc: Juergen Gross Cc: Qian Cai Cc: Arun KS Cc: Nick Desaulniers Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/base/node.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'drivers/base/node.c') diff --git a/drivers/base/node.c b/drivers/base/node.c index 27391f1e8f60..75b7e6f6535b 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -834,8 +834,9 @@ void unregister_memory_block_under_nodes(struct memory_block *mem_blk) int link_mem_sections(int nid, unsigned long start_pfn, unsigned long end_pfn) { - return walk_memory_range(start_pfn, end_pfn, (void *)&nid, - register_mem_sect_under_node); + return walk_memory_blocks(PFN_PHYS(start_pfn), + PFN_PHYS(end_pfn - start_pfn), (void *)&nid, + register_mem_sect_under_node); } #ifdef CONFIG_HUGETLBFS -- cgit v1.2.3