From 2491f0a2c0b117b9097e9c9eee0c21f2e5f716d7 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 18 Jul 2019 15:57:37 -0700 Subject: mm: section numbers use the type "unsigned long" Patch series "mm: Further memory block device cleanups", v1. Some further cleanups around memory block devices. Especially, clean up and simplify walk_memory_range(). Including some other minor cleanups. This patch (of 6): We are using a mixture of "int" and "unsigned long". Let's make this consistent by using "unsigned long" everywhere. We'll do the same with memory block ids next. While at it, turn the "unsigned long i" in removable_show() into an int - sections_per_block is an int. [akpm@linux-foundation.org: s/unsigned long i/unsigned long nr/] [david@redhat.com: v3] Link: http://lkml.kernel.org/r/20190620183139.4352-2-david@redhat.com Link: http://lkml.kernel.org/r/20190614100114.311-2-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Andrew Morton Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: Vlastimil Babka Cc: Michal Hocko Cc: Dan Williams Cc: Mel Gorman Cc: Wei Yang Cc: Johannes Weiner Cc: Arun KS Cc: Pavel Tatashin Cc: Oscar Salvador Cc: Stephen Rothwell Cc: Mike Rapoport Cc: Baoquan He Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mmzone.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux/mmzone.h') diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 70394cabaf4e..298d1c3e4c2e 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1219,7 +1219,7 @@ static inline struct mem_section *__nr_to_section(unsigned long nr) return NULL; return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK]; } -extern int __section_nr(struct mem_section* ms); +extern unsigned long __section_nr(struct mem_section *ms); extern unsigned long usemap_size(void); /* @@ -1291,7 +1291,7 @@ static inline struct mem_section *__pfn_to_section(unsigned long pfn) return __nr_to_section(pfn_to_section_nr(pfn)); } -extern int __highest_present_section_nr; +extern unsigned long __highest_present_section_nr; #ifndef CONFIG_HAVE_ARCH_PFN_VALID static inline int pfn_valid(unsigned long pfn) -- cgit v1.3-14-g43fede From f1eca35a0dc7cb3cdb00c88c8c5e5138a65face0 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Thu, 18 Jul 2019 15:57:57 -0700 Subject: mm/sparsemem: introduce struct mem_section_usage MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Patch series "mm: Sub-section memory hotplug support", v10. The memory hotplug section is an arbitrary / convenient unit for memory hotplug. 'Section-size' units have bled into the user interface ('memblock' sysfs) and can not be changed without breaking existing userspace. The section-size constraint, while mostly benign for typical memory hotplug, has and continues to wreak havoc with 'device-memory' use cases, persistent memory (pmem) in particular. Recall that pmem uses devm_memremap_pages(), and subsequently arch_add_memory(), to allocate a 'struct page' memmap for pmem. However, it does not use the 'bottom half' of memory hotplug, i.e. never marks pmem pages online and never exposes the userspace memblock interface for pmem. This leaves an opening to redress the section-size constraint. To date, the libnvdimm subsystem has attempted to inject padding to satisfy the internal constraints of arch_add_memory(). Beyond complicating the code, leading to bugs [2], wasting memory, and limiting configuration flexibility, the padding hack is broken when the platform changes this physical memory alignment of pmem from one boot to the next. Device failure (intermittent or permanent) and physical reconfiguration are events that can cause the platform firmware to change the physical placement of pmem on a subsequent boot, and device failure is an everyday event in a data-center. It turns out that sections are only a hard requirement of the user-facing interface for memory hotplug and with a bit more infrastructure sub-section arch_add_memory() support can be added for kernel internal usages like devm_memremap_pages(). Here is an analysis of the current design assumptions in the current code and how they are addressed in the new implementation: Current design assumptions: - Sections that describe boot memory (early sections) are never unplugged / removed. - pfn_valid(), in the CONFIG_SPARSEMEM_VMEMMAP=y, case devolves to a valid_section() check - __add_pages() and helper routines assume all operations occur in PAGES_PER_SECTION units. - The memblock sysfs interface only comprehends full sections New design assumptions: - Sections are instrumented with a sub-section bitmask to track (on x86) individual 2MB sub-divisions of a 128MB section. - Partially populated early sections can be extended with additional sub-sections, and those sub-sections can be removed with arch_remove_memory(). With this in place we no longer lose usable memory capacity to padding. - pfn_valid() is updated to look deeper than valid_section() to also check the active-sub-section mask. This indication is in the same cacheline as the valid_section() so the performance impact is expected to be negligible. So far the lkp robot has not reported any regressions. - Outside of the core vmemmap population routines which are replaced, other helper routines like shrink_{zone,pgdat}_span() are updated to handle the smaller granularity. Core memory hotplug routines that deal with online memory are not touched. - The existing memblock sysfs user api guarantees / assumptions are not touched since this capability is limited to !online !memblock-sysfs-accessible sections. Meanwhile the issue reports continue to roll in from users that do not understand when and how the 128MB constraint will bite them. The current implementation relied on being able to support at least one misaligned namespace, but that immediately falls over on any moderately complex namespace creation attempt. Beyond the initial problem of 'System RAM' colliding with pmem, and the unsolvable problem of physical alignment changes, Linux is now being exposed to platforms that collide pmem ranges with other pmem ranges by default [3]. In short, devm_memremap_pages() has pushed the venerable section-size constraint past the breaking point, and the simplicity of section-aligned arch_add_memory() is no longer tenable. These patches are exposed to the kbuild robot on a subsection-v10 branch [4], and a preview of the unit test for this functionality is available on the 'subsection-pending' branch of ndctl [5]. [2]: https://lore.kernel.org/r/155000671719.348031.2347363160141119237.stgit@dwillia2-desk3.amr.corp.intel.com [3]: https://github.com/pmem/ndctl/issues/76 [4]: https://git.kernel.org/pub/scm/linux/kernel/git/djbw/nvdimm.git/log/?h=subsection-v10 [5]: https://github.com/pmem/ndctl/commit/7c59b4867e1c This patch (of 13): Towards enabling memory hotplug to track partial population of a section, introduce 'struct mem_section_usage'. A pointer to a 'struct mem_section_usage' instance replaces the existing pointer to a 'pageblock_flags' bitmap. Effectively it adds one more 'unsigned long' beyond the 'pageblock_flags' (usemap) allocation to house a new 'subsection_map' bitmap. The new bitmap enables the memory hot{plug,remove} implementation to act on incremental sub-divisions of a section. SUBSECTION_SHIFT is defined as global constant instead of per-architecture value like SECTION_SIZE_BITS in order to allow cross-arch compatibility of subsection users. Specifically a common subsection size allows for the possibility that persistent memory namespace configurations be made compatible across architectures. The primary motivation for this functionality is to support platforms that mix "System RAM" and "Persistent Memory" within a single section, or multiple PMEM ranges with different mapping lifetimes within a single section. The section restriction for hotplug has caused an ongoing saga of hacks and bugs for devm_memremap_pages() users. Beyond the fixups to teach existing paths how to retrieve the 'usemap' from a section, and updates to usemap allocation path, there are no expected behavior changes. Link: http://lkml.kernel.org/r/156092349845.979959.73333291612799019.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams Reviewed-by: Oscar Salvador Reviewed-by: Wei Yang Tested-by: Aneesh Kumar K.V [ppc64] Cc: Michal Hocko Cc: Vlastimil Babka Cc: Logan Gunthorpe Cc: Pavel Tatashin Cc: David Hildenbrand Cc: Jérôme Glisse Cc: Mike Rapoport Cc: Jane Chu Cc: Pavel Tatashin Cc: Jonathan Corbet Cc: Qian Cai Cc: Logan Gunthorpe Cc: Toshi Kani Cc: Jeff Moyer Cc: Michal Hocko Cc: Vlastimil Babka Cc: Jason Gunthorpe Cc: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mmzone.h | 28 +++++++++++++++-- mm/memory_hotplug.c | 18 ++++++----- mm/page_alloc.c | 2 +- mm/sparse.c | 81 +++++++++++++++++++++++++------------------------- 4 files changed, 76 insertions(+), 53 deletions(-) (limited to 'include/linux/mmzone.h') diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 298d1c3e4c2e..2520336bdfd1 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1160,6 +1160,24 @@ static inline unsigned long section_nr_to_pfn(unsigned long sec) #define SECTION_ALIGN_UP(pfn) (((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK) #define SECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SECTION_MASK) +#define SUBSECTION_SHIFT 21 + +#define PFN_SUBSECTION_SHIFT (SUBSECTION_SHIFT - PAGE_SHIFT) +#define PAGES_PER_SUBSECTION (1UL << PFN_SUBSECTION_SHIFT) +#define PAGE_SUBSECTION_MASK (~(PAGES_PER_SUBSECTION-1)) + +#if SUBSECTION_SHIFT > SECTION_SIZE_BITS +#error Subsection size exceeds section size +#else +#define SUBSECTIONS_PER_SECTION (1UL << (SECTION_SIZE_BITS - SUBSECTION_SHIFT)) +#endif + +struct mem_section_usage { + DECLARE_BITMAP(subsection_map, SUBSECTIONS_PER_SECTION); + /* See declaration of similar field in struct zone */ + unsigned long pageblock_flags[0]; +}; + struct page; struct page_ext; struct mem_section { @@ -1177,8 +1195,7 @@ struct mem_section { */ unsigned long section_mem_map; - /* See declaration of similar field in struct zone */ - unsigned long *pageblock_flags; + struct mem_section_usage *usage; #ifdef CONFIG_PAGE_EXTENSION /* * If SPARSEMEM, pgdat doesn't have page_ext pointer. We use @@ -1209,6 +1226,11 @@ extern struct mem_section **mem_section; extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]; #endif +static inline unsigned long *section_to_usemap(struct mem_section *ms) +{ + return ms->usage->pageblock_flags; +} + static inline struct mem_section *__nr_to_section(unsigned long nr) { #ifdef CONFIG_SPARSEMEM_EXTREME @@ -1220,7 +1242,7 @@ static inline struct mem_section *__nr_to_section(unsigned long nr) return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK]; } extern unsigned long __section_nr(struct mem_section *ms); -extern unsigned long usemap_size(void); +extern size_t mem_section_usage_size(void); /* * We use the lower bits of the mem_map pointer to store diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index fafee5f13ef2..cf9d979a6498 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -166,9 +166,10 @@ void put_page_bootmem(struct page *page) #ifndef CONFIG_SPARSEMEM_VMEMMAP static void register_page_bootmem_info_section(unsigned long start_pfn) { - unsigned long *usemap, mapsize, section_nr, i; + unsigned long mapsize, section_nr, i; struct mem_section *ms; struct page *page, *memmap; + struct mem_section_usage *usage; section_nr = pfn_to_section_nr(start_pfn); ms = __nr_to_section(section_nr); @@ -188,10 +189,10 @@ static void register_page_bootmem_info_section(unsigned long start_pfn) for (i = 0; i < mapsize; i++, page++) get_page_bootmem(section_nr, page, SECTION_INFO); - usemap = ms->pageblock_flags; - page = virt_to_page(usemap); + usage = ms->usage; + page = virt_to_page(usage); - mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT; + mapsize = PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT; for (i = 0; i < mapsize; i++, page++) get_page_bootmem(section_nr, page, MIX_SECTION_INFO); @@ -200,9 +201,10 @@ static void register_page_bootmem_info_section(unsigned long start_pfn) #else /* CONFIG_SPARSEMEM_VMEMMAP */ static void register_page_bootmem_info_section(unsigned long start_pfn) { - unsigned long *usemap, mapsize, section_nr, i; + unsigned long mapsize, section_nr, i; struct mem_section *ms; struct page *page, *memmap; + struct mem_section_usage *usage; section_nr = pfn_to_section_nr(start_pfn); ms = __nr_to_section(section_nr); @@ -211,10 +213,10 @@ static void register_page_bootmem_info_section(unsigned long start_pfn) register_page_bootmem_memmap(section_nr, memmap, PAGES_PER_SECTION); - usemap = ms->pageblock_flags; - page = virt_to_page(usemap); + usage = ms->usage; + page = virt_to_page(usage); - mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT; + mapsize = PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT; for (i = 0; i < mapsize; i++, page++) get_page_bootmem(section_nr, page, MIX_SECTION_INFO); diff --git a/mm/page_alloc.c b/mm/page_alloc.c index e515bfcf7f28..be78bafbfe3a 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -450,7 +450,7 @@ static inline unsigned long *get_pageblock_bitmap(struct page *page, unsigned long pfn) { #ifdef CONFIG_SPARSEMEM - return __pfn_to_section(pfn)->pageblock_flags; + return section_to_usemap(__pfn_to_section(pfn)); #else return page_zone(page)->pageblock_flags; #endif /* CONFIG_SPARSEMEM */ diff --git a/mm/sparse.c b/mm/sparse.c index b29534cea8c0..41bef8e1f65c 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -288,33 +288,31 @@ struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pn static void __meminit sparse_init_one_section(struct mem_section *ms, unsigned long pnum, struct page *mem_map, - unsigned long *pageblock_bitmap) + struct mem_section_usage *usage) { ms->section_mem_map &= ~SECTION_MAP_MASK; ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum) | SECTION_HAS_MEM_MAP; - ms->pageblock_flags = pageblock_bitmap; + ms->usage = usage; } -unsigned long usemap_size(void) +static unsigned long usemap_size(void) { return BITS_TO_LONGS(SECTION_BLOCKFLAGS_BITS) * sizeof(unsigned long); } -#ifdef CONFIG_MEMORY_HOTPLUG -static unsigned long *__kmalloc_section_usemap(void) +size_t mem_section_usage_size(void) { - return kmalloc(usemap_size(), GFP_KERNEL); + return sizeof(struct mem_section_usage) + usemap_size(); } -#endif /* CONFIG_MEMORY_HOTPLUG */ #ifdef CONFIG_MEMORY_HOTREMOVE -static unsigned long * __init +static struct mem_section_usage * __init sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat, unsigned long size) { + struct mem_section_usage *usage; unsigned long goal, limit; - unsigned long *p; int nid; /* * A page may contain usemaps for other sections preventing the @@ -330,15 +328,16 @@ sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat, limit = goal + (1UL << PA_SECTION_SHIFT); nid = early_pfn_to_nid(goal >> PAGE_SHIFT); again: - p = memblock_alloc_try_nid(size, SMP_CACHE_BYTES, goal, limit, nid); - if (!p && limit) { + usage = memblock_alloc_try_nid(size, SMP_CACHE_BYTES, goal, limit, nid); + if (!usage && limit) { limit = 0; goto again; } - return p; + return usage; } -static void __init check_usemap_section_nr(int nid, unsigned long *usemap) +static void __init check_usemap_section_nr(int nid, + struct mem_section_usage *usage) { unsigned long usemap_snr, pgdat_snr; static unsigned long old_usemap_snr; @@ -352,7 +351,7 @@ static void __init check_usemap_section_nr(int nid, unsigned long *usemap) old_pgdat_snr = NR_MEM_SECTIONS; } - usemap_snr = pfn_to_section_nr(__pa(usemap) >> PAGE_SHIFT); + usemap_snr = pfn_to_section_nr(__pa(usage) >> PAGE_SHIFT); pgdat_snr = pfn_to_section_nr(__pa(pgdat) >> PAGE_SHIFT); if (usemap_snr == pgdat_snr) return; @@ -380,14 +379,15 @@ static void __init check_usemap_section_nr(int nid, unsigned long *usemap) usemap_snr, pgdat_snr, nid); } #else -static unsigned long * __init +static struct mem_section_usage * __init sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat, unsigned long size) { return memblock_alloc_node(size, SMP_CACHE_BYTES, pgdat->node_id); } -static void __init check_usemap_section_nr(int nid, unsigned long *usemap) +static void __init check_usemap_section_nr(int nid, + struct mem_section_usage *usage) { } #endif /* CONFIG_MEMORY_HOTREMOVE */ @@ -474,14 +474,13 @@ static void __init sparse_init_nid(int nid, unsigned long pnum_begin, unsigned long pnum_end, unsigned long map_count) { - unsigned long pnum, usemap_longs, *usemap; + struct mem_section_usage *usage; + unsigned long pnum; struct page *map; - usemap_longs = BITS_TO_LONGS(SECTION_BLOCKFLAGS_BITS); - usemap = sparse_early_usemaps_alloc_pgdat_section(NODE_DATA(nid), - usemap_size() * - map_count); - if (!usemap) { + usage = sparse_early_usemaps_alloc_pgdat_section(NODE_DATA(nid), + mem_section_usage_size() * map_count); + if (!usage) { pr_err("%s: node[%d] usemap allocation failed", __func__, nid); goto failed; } @@ -497,9 +496,9 @@ static void __init sparse_init_nid(int nid, unsigned long pnum_begin, pnum_begin = pnum; goto failed; } - check_usemap_section_nr(nid, usemap); - sparse_init_one_section(__nr_to_section(pnum), pnum, map, usemap); - usemap += usemap_longs; + check_usemap_section_nr(nid, usage); + sparse_init_one_section(__nr_to_section(pnum), pnum, map, usage); + usage = (void *) usage + mem_section_usage_size(); } sparse_buffer_fini(); return; @@ -697,9 +696,9 @@ int __meminit sparse_add_one_section(int nid, unsigned long start_pfn, struct vmem_altmap *altmap) { unsigned long section_nr = pfn_to_section_nr(start_pfn); + struct mem_section_usage *usage; struct mem_section *ms; struct page *memmap; - unsigned long *usemap; int ret; /* @@ -713,8 +712,8 @@ int __meminit sparse_add_one_section(int nid, unsigned long start_pfn, memmap = kmalloc_section_memmap(section_nr, nid, altmap); if (!memmap) return -ENOMEM; - usemap = __kmalloc_section_usemap(); - if (!usemap) { + usage = kzalloc(mem_section_usage_size(), GFP_KERNEL); + if (!usage) { __kfree_section_memmap(memmap, altmap); return -ENOMEM; } @@ -733,11 +732,11 @@ int __meminit sparse_add_one_section(int nid, unsigned long start_pfn, set_section_nid(section_nr, nid); section_mark_present(ms); - sparse_init_one_section(ms, section_nr, memmap, usemap); + sparse_init_one_section(ms, section_nr, memmap, usage); out: if (ret < 0) { - kfree(usemap); + kfree(usage); __kfree_section_memmap(memmap, altmap); } return ret; @@ -773,20 +772,20 @@ static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages) } #endif -static void free_section_usemap(struct page *memmap, unsigned long *usemap, - struct vmem_altmap *altmap) +static void free_section_usage(struct page *memmap, + struct mem_section_usage *usage, struct vmem_altmap *altmap) { - struct page *usemap_page; + struct page *usage_page; - if (!usemap) + if (!usage) return; - usemap_page = virt_to_page(usemap); + usage_page = virt_to_page(usage); /* * Check to see if allocation came from hot-plug-add */ - if (PageSlab(usemap_page) || PageCompound(usemap_page)) { - kfree(usemap); + if (PageSlab(usage_page) || PageCompound(usage_page)) { + kfree(usage); if (memmap) __kfree_section_memmap(memmap, altmap); return; @@ -805,18 +804,18 @@ void sparse_remove_one_section(struct mem_section *ms, unsigned long map_offset, struct vmem_altmap *altmap) { struct page *memmap = NULL; - unsigned long *usemap = NULL; + struct mem_section_usage *usage = NULL; if (ms->section_mem_map) { - usemap = ms->pageblock_flags; + usage = ms->usage; memmap = sparse_decode_mem_map(ms->section_mem_map, __section_nr(ms)); ms->section_mem_map = 0; - ms->pageblock_flags = NULL; + ms->usage = NULL; } clear_hwpoisoned_pages(memmap + map_offset, PAGES_PER_SECTION - map_offset); - free_section_usemap(memmap, usemap, altmap); + free_section_usage(memmap, usage, altmap); } #endif /* CONFIG_MEMORY_HOTPLUG */ -- cgit v1.3-14-g43fede From 326e1b8f83a4318b09033ef754f40c785aed5e68 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Thu, 18 Jul 2019 15:58:00 -0700 Subject: mm/sparsemem: introduce a SECTION_IS_EARLY flag MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In preparation for sub-section hotplug, track whether a given section was created during early memory initialization, or later via memory hotplug. This distinction is needed to maintain the coarse expectation that pfn_valid() returns true for any pfn within a given section even if that section has pages that are reserved from the page allocator. For example one of the of goals of subsection hotplug is to support cases where the system physical memory layout collides System RAM and PMEM within a section. Several pfn_valid() users expect to just check if a section is valid, but they are not careful to check if the given pfn is within a "System RAM" boundary and instead expect pgdat information to further validate the pfn. Rather than unwind those paths to make their pfn_valid() queries more precise a follow on patch uses the SECTION_IS_EARLY flag to maintain the traditional expectation that pfn_valid() returns true for all early sections. Link: https://lore.kernel.org/lkml/1560366952-10660-1-git-send-email-cai@lca.pw/ Link: http://lkml.kernel.org/r/156092350358.979959.5817209875548072819.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams Reported-by: Qian Cai Tested-by: Aneesh Kumar K.V [ppc64] Reviewed-by: Oscar Salvador Cc: Michal Hocko Cc: Logan Gunthorpe Cc: David Hildenbrand Cc: Pavel Tatashin Cc: Jane Chu Cc: Jeff Moyer Cc: Jérôme Glisse Cc: Jonathan Corbet Cc: Mike Rapoport Cc: Toshi Kani Cc: Vlastimil Babka Cc: Wei Yang Cc: Jason Gunthorpe Cc: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mmzone.h | 8 +++++++- mm/sparse.c | 20 +++++++++----------- 2 files changed, 16 insertions(+), 12 deletions(-) (limited to 'include/linux/mmzone.h') diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 2520336bdfd1..4be40634238b 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1260,7 +1260,8 @@ extern size_t mem_section_usage_size(void); #define SECTION_MARKED_PRESENT (1UL<<0) #define SECTION_HAS_MEM_MAP (1UL<<1) #define SECTION_IS_ONLINE (1UL<<2) -#define SECTION_MAP_LAST_BIT (1UL<<3) +#define SECTION_IS_EARLY (1UL<<3) +#define SECTION_MAP_LAST_BIT (1UL<<4) #define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1)) #define SECTION_NID_SHIFT 3 @@ -1286,6 +1287,11 @@ static inline int valid_section(struct mem_section *section) return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP)); } +static inline int early_section(struct mem_section *section) +{ + return (section && (section->section_mem_map & SECTION_IS_EARLY)); +} + static inline int valid_section_nr(unsigned long nr) { return valid_section(__nr_to_section(nr)); diff --git a/mm/sparse.c b/mm/sparse.c index 41bef8e1f65c..6d23a526279a 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -288,11 +288,11 @@ struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pn static void __meminit sparse_init_one_section(struct mem_section *ms, unsigned long pnum, struct page *mem_map, - struct mem_section_usage *usage) + struct mem_section_usage *usage, unsigned long flags) { ms->section_mem_map &= ~SECTION_MAP_MASK; - ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum) | - SECTION_HAS_MEM_MAP; + ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum) + | SECTION_HAS_MEM_MAP | flags; ms->usage = usage; } @@ -497,7 +497,8 @@ static void __init sparse_init_nid(int nid, unsigned long pnum_begin, goto failed; } check_usemap_section_nr(nid, usage); - sparse_init_one_section(__nr_to_section(pnum), pnum, map, usage); + sparse_init_one_section(__nr_to_section(pnum), pnum, map, usage, + SECTION_IS_EARLY); usage = (void *) usage + mem_section_usage_size(); } sparse_buffer_fini(); @@ -732,7 +733,7 @@ int __meminit sparse_add_one_section(int nid, unsigned long start_pfn, set_section_nid(section_nr, nid); section_mark_present(ms); - sparse_init_one_section(ms, section_nr, memmap, usage); + sparse_init_one_section(ms, section_nr, memmap, usage, 0); out: if (ret < 0) { @@ -772,19 +773,16 @@ static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages) } #endif -static void free_section_usage(struct page *memmap, +static void free_section_usage(struct mem_section *ms, struct page *memmap, struct mem_section_usage *usage, struct vmem_altmap *altmap) { - struct page *usage_page; - if (!usage) return; - usage_page = virt_to_page(usage); /* * Check to see if allocation came from hot-plug-add */ - if (PageSlab(usage_page) || PageCompound(usage_page)) { + if (!early_section(ms)) { kfree(usage); if (memmap) __kfree_section_memmap(memmap, altmap); @@ -816,6 +814,6 @@ void sparse_remove_one_section(struct mem_section *ms, unsigned long map_offset, clear_hwpoisoned_pages(memmap + map_offset, PAGES_PER_SECTION - map_offset); - free_section_usage(memmap, usage, altmap); + free_section_usage(ms, memmap, usage, altmap); } #endif /* CONFIG_MEMORY_HOTPLUG */ -- cgit v1.3-14-g43fede From f46edbd1b1516da1fb34c917775168d5df576f78 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Thu, 18 Jul 2019 15:58:04 -0700 Subject: mm/sparsemem: add helpers track active portions of a section at boot MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Prepare for hot{plug,remove} of sub-ranges of a section by tracking a sub-section active bitmask, each bit representing a PMD_SIZE span of the architecture's memory hotplug section size. The implications of a partially populated section is that pfn_valid() needs to go beyond a valid_section() check and either determine that the section is an "early section", or read the sub-section active ranges from the bitmask. The expectation is that the bitmask (subsection_map) fits in the same cacheline as the valid_section() / early_section() data, so the incremental performance overhead to pfn_valid() should be negligible. The rationale for using early_section() to short-ciruit the subsection_map check is that there are legacy code paths that use pfn_valid() at section granularity before validating the pfn against pgdat data. So, the early_section() check allows those traditional assumptions to persist while also permitting subsection_map to tell the truth for purposes of populating the unused portions of early sections with PMEM and other ZONE_DEVICE mappings. Link: http://lkml.kernel.org/r/156092350874.979959.18185938451405518285.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams Reported-by: Qian Cai Tested-by: Jane Chu Tested-by: Aneesh Kumar K.V [ppc64] Reviewed-by: Oscar Salvador Cc: Michal Hocko Cc: Vlastimil Babka Cc: Logan Gunthorpe Cc: Pavel Tatashin Cc: David Hildenbrand Cc: Jeff Moyer Cc: Jérôme Glisse Cc: Jonathan Corbet Cc: Mike Rapoport Cc: Toshi Kani Cc: Wei Yang Cc: Jason Gunthorpe Cc: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mmzone.h | 33 ++++++++++++++++++++++++++++++++- mm/page_alloc.c | 10 ++++++++-- mm/sparse.c | 35 +++++++++++++++++++++++++++++++++++ 3 files changed, 75 insertions(+), 3 deletions(-) (limited to 'include/linux/mmzone.h') diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 4be40634238b..7747ec9de588 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1178,6 +1178,8 @@ struct mem_section_usage { unsigned long pageblock_flags[0]; }; +void subsection_map_init(unsigned long pfn, unsigned long nr_pages); + struct page; struct page_ext; struct mem_section { @@ -1321,12 +1323,40 @@ static inline struct mem_section *__pfn_to_section(unsigned long pfn) extern unsigned long __highest_present_section_nr; +static inline int subsection_map_index(unsigned long pfn) +{ + return (pfn & ~(PAGE_SECTION_MASK)) / PAGES_PER_SUBSECTION; +} + +#ifdef CONFIG_SPARSEMEM_VMEMMAP +static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn) +{ + int idx = subsection_map_index(pfn); + + return test_bit(idx, ms->usage->subsection_map); +} +#else +static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn) +{ + return 1; +} +#endif + #ifndef CONFIG_HAVE_ARCH_PFN_VALID static inline int pfn_valid(unsigned long pfn) { + struct mem_section *ms; + if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) return 0; - return valid_section(__nr_to_section(pfn_to_section_nr(pfn))); + ms = __nr_to_section(pfn_to_section_nr(pfn)); + if (!valid_section(ms)) + return 0; + /* + * Traditionally early sections always returned pfn_valid() for + * the entire section-sized span. + */ + return early_section(ms) || pfn_section_valid(ms, pfn); } #endif @@ -1358,6 +1388,7 @@ void sparse_init(void); #define sparse_init() do {} while (0) #define sparse_index_init(_sec, _nid) do {} while (0) #define pfn_present pfn_valid +#define subsection_map_init(_pfn, _nr_pages) do {} while (0) #endif /* CONFIG_SPARSEMEM */ /* diff --git a/mm/page_alloc.c b/mm/page_alloc.c index be78bafbfe3a..c4cdd3954804 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -7351,12 +7351,18 @@ void __init free_area_init_nodes(unsigned long *max_zone_pfn) (u64)zone_movable_pfn[i] << PAGE_SHIFT); } - /* Print out the early node map */ + /* + * Print out the early node map, and initialize the + * subsection-map relative to active online memory ranges to + * enable future "sub-section" extensions of the memory map. + */ pr_info("Early memory node ranges\n"); - for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) + for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) { pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid, (u64)start_pfn << PAGE_SHIFT, ((u64)end_pfn << PAGE_SHIFT) - 1); + subsection_map_init(start_pfn, end_pfn - start_pfn); + } /* Initialise every node */ mminit_verify_pageflags_layout(); diff --git a/mm/sparse.c b/mm/sparse.c index 6d23a526279a..26b48ee1a262 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -210,6 +210,41 @@ static inline unsigned long first_present_section_nr(void) return next_present_section_nr(-1); } +void subsection_mask_set(unsigned long *map, unsigned long pfn, + unsigned long nr_pages) +{ + int idx = subsection_map_index(pfn); + int end = subsection_map_index(pfn + nr_pages - 1); + + bitmap_set(map, idx, end - idx + 1); +} + +void __init subsection_map_init(unsigned long pfn, unsigned long nr_pages) +{ + int end_sec = pfn_to_section_nr(pfn + nr_pages - 1); + int i, start_sec = pfn_to_section_nr(pfn); + + if (!nr_pages) + return; + + for (i = start_sec; i <= end_sec; i++) { + struct mem_section *ms; + unsigned long pfns; + + pfns = min(nr_pages, PAGES_PER_SECTION + - (pfn & ~PAGE_SECTION_MASK)); + ms = __nr_to_section(i); + subsection_mask_set(ms->usage->subsection_map, pfn, pfns); + + pr_debug("%s: sec: %d pfns: %ld set(%d, %d)\n", __func__, i, + pfns, subsection_map_index(pfn), + subsection_map_index(pfn + pfns - 1)); + + pfn += pfns; + nr_pages -= pfns; + } +} + /* Record a memory area against a node. */ void __init memory_present(int nid, unsigned long start, unsigned long end) { -- cgit v1.3-14-g43fede From 46d945aeab4d7dd837bd0724662de2caf712f047 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Thu, 18 Jul 2019 15:58:18 -0700 Subject: mm: kill is_dev_zone() helper MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Given there are no more usages of is_dev_zone() outside of 'ifdef CONFIG_ZONE_DEVICE' protection, kill off the compilation helper. Link: http://lkml.kernel.org/r/156092353211.979959.1489004866360828964.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams Reviewed-by: Oscar Salvador Reviewed-by: Pavel Tatashin Reviewed-by: Wei Yang Acked-by: David Hildenbrand Tested-by: Aneesh Kumar K.V [ppc64] Cc: Michal Hocko Cc: Logan Gunthorpe Cc: Jane Chu Cc: Jeff Moyer Cc: Jérôme Glisse Cc: Jonathan Corbet Cc: Mike Rapoport Cc: Toshi Kani Cc: Vlastimil Babka Cc: Jason Gunthorpe Cc: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mmzone.h | 12 ------------ mm/page_alloc.c | 2 +- 2 files changed, 1 insertion(+), 13 deletions(-) (limited to 'include/linux/mmzone.h') diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 7747ec9de588..8331e76677c0 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -855,18 +855,6 @@ static inline int local_memory_node(int node_id) { return node_id; }; */ #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones) -#ifdef CONFIG_ZONE_DEVICE -static inline bool is_dev_zone(const struct zone *zone) -{ - return zone_idx(zone) == ZONE_DEVICE; -} -#else -static inline bool is_dev_zone(const struct zone *zone) -{ - return false; -} -#endif - /* * Returns true if a zone has pages managed by the buddy allocator. * All the reclaim decisions have to use this function rather than diff --git a/mm/page_alloc.c b/mm/page_alloc.c index c4cdd3954804..2c74367a8eba 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5926,7 +5926,7 @@ void __ref memmap_init_zone_device(struct zone *zone, unsigned long start = jiffies; int nid = pgdat->node_id; - if (WARN_ON_ONCE(!pgmap || !is_dev_zone(zone))) + if (WARN_ON_ONCE(!pgmap || zone_idx(zone) != ZONE_DEVICE)) return; /* -- cgit v1.3-14-g43fede From a3619190d62ed9d66416891be2416f6bea2b3ca4 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Thu, 18 Jul 2019 15:58:40 -0700 Subject: libnvdimm/pfn: stop padding pmem namespaces to section alignment MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Now that the mm core supports section-unaligned hotplug of ZONE_DEVICE memory, we no longer need to add padding at pfn/dax device creation time. The kernel will still honor padding established by older kernels. Link: http://lkml.kernel.org/r/156092356588.979959.6793371748950931916.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams Reported-by: Jeff Moyer Tested-by: Aneesh Kumar K.V [ppc64] Cc: David Hildenbrand Cc: Jane Chu Cc: Jérôme Glisse Cc: Jonathan Corbet Cc: Logan Gunthorpe Cc: Michal Hocko Cc: Mike Rapoport Cc: Oscar Salvador Cc: Pavel Tatashin Cc: Toshi Kani Cc: Vlastimil Babka Cc: Wei Yang Cc: Jason Gunthorpe Cc: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/nvdimm/pfn.h | 14 --------- drivers/nvdimm/pfn_devs.c | 77 ++++++++--------------------------------------- include/linux/mmzone.h | 3 ++ 3 files changed, 16 insertions(+), 78 deletions(-) (limited to 'include/linux/mmzone.h') diff --git a/drivers/nvdimm/pfn.h b/drivers/nvdimm/pfn.h index dfb2bcda8f5a..7381673b7b70 100644 --- a/drivers/nvdimm/pfn.h +++ b/drivers/nvdimm/pfn.h @@ -33,18 +33,4 @@ struct nd_pfn_sb { __le64 checksum; }; -#ifdef CONFIG_SPARSEMEM -#define PFN_SECTION_ALIGN_DOWN(x) SECTION_ALIGN_DOWN(x) -#define PFN_SECTION_ALIGN_UP(x) SECTION_ALIGN_UP(x) -#else -/* - * In this case ZONE_DEVICE=n and we will disable 'pfn' device support, - * but we still want pmem to compile. - */ -#define PFN_SECTION_ALIGN_DOWN(x) (x) -#define PFN_SECTION_ALIGN_UP(x) (x) -#endif - -#define PHYS_SECTION_ALIGN_DOWN(x) PFN_PHYS(PFN_SECTION_ALIGN_DOWN(PHYS_PFN(x))) -#define PHYS_SECTION_ALIGN_UP(x) PFN_PHYS(PFN_SECTION_ALIGN_UP(PHYS_PFN(x))) #endif /* __NVDIMM_PFN_H */ diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c index 06f465c0baf3..df2bdbd22450 100644 --- a/drivers/nvdimm/pfn_devs.c +++ b/drivers/nvdimm/pfn_devs.c @@ -587,14 +587,14 @@ static u32 info_block_reserve(void) } /* - * We hotplug memory at section granularity, pad the reserved area from - * the previous section base to the namespace base address. + * We hotplug memory at sub-section granularity, pad the reserved area + * from the previous section base to the namespace base address. */ static unsigned long init_altmap_base(resource_size_t base) { unsigned long base_pfn = PHYS_PFN(base); - return PFN_SECTION_ALIGN_DOWN(base_pfn); + return SUBSECTION_ALIGN_DOWN(base_pfn); } static unsigned long init_altmap_reserve(resource_size_t base) @@ -602,7 +602,7 @@ static unsigned long init_altmap_reserve(resource_size_t base) unsigned long reserve = info_block_reserve() >> PAGE_SHIFT; unsigned long base_pfn = PHYS_PFN(base); - reserve += base_pfn - PFN_SECTION_ALIGN_DOWN(base_pfn); + reserve += base_pfn - SUBSECTION_ALIGN_DOWN(base_pfn); return reserve; } @@ -632,8 +632,7 @@ static int __nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap) return -EINVAL; nd_pfn->npfns = le64_to_cpu(pfn_sb->npfns); } else if (nd_pfn->mode == PFN_MODE_PMEM) { - nd_pfn->npfns = PFN_SECTION_ALIGN_UP((resource_size(res) - - offset) / PAGE_SIZE); + nd_pfn->npfns = PHYS_PFN((resource_size(res) - offset)); if (le64_to_cpu(nd_pfn->pfn_sb->npfns) > nd_pfn->npfns) dev_info(&nd_pfn->dev, "number of pfns truncated from %lld to %ld\n", @@ -649,54 +648,14 @@ static int __nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap) return 0; } -static u64 phys_pmem_align_down(struct nd_pfn *nd_pfn, u64 phys) -{ - return min_t(u64, PHYS_SECTION_ALIGN_DOWN(phys), - ALIGN_DOWN(phys, nd_pfn->align)); -} - -/* - * Check if pmem collides with 'System RAM', or other regions when - * section aligned. Trim it accordingly. - */ -static void trim_pfn_device(struct nd_pfn *nd_pfn, u32 *start_pad, u32 *end_trunc) -{ - struct nd_namespace_common *ndns = nd_pfn->ndns; - struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev); - struct nd_region *nd_region = to_nd_region(nd_pfn->dev.parent); - const resource_size_t start = nsio->res.start; - const resource_size_t end = start + resource_size(&nsio->res); - resource_size_t adjust, size; - - *start_pad = 0; - *end_trunc = 0; - - adjust = start - PHYS_SECTION_ALIGN_DOWN(start); - size = resource_size(&nsio->res) + adjust; - if (region_intersects(start - adjust, size, IORESOURCE_SYSTEM_RAM, - IORES_DESC_NONE) == REGION_MIXED - || nd_region_conflict(nd_region, start - adjust, size)) - *start_pad = PHYS_SECTION_ALIGN_UP(start) - start; - - /* Now check that end of the range does not collide. */ - adjust = PHYS_SECTION_ALIGN_UP(end) - end; - size = resource_size(&nsio->res) + adjust; - if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM, - IORES_DESC_NONE) == REGION_MIXED - || !IS_ALIGNED(end, nd_pfn->align) - || nd_region_conflict(nd_region, start, size)) - *end_trunc = end - phys_pmem_align_down(nd_pfn, end); -} - static int nd_pfn_init(struct nd_pfn *nd_pfn) { struct nd_namespace_common *ndns = nd_pfn->ndns; struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev); - u32 start_pad, end_trunc, reserve = info_block_reserve(); resource_size_t start, size; struct nd_region *nd_region; + unsigned long npfns, align; struct nd_pfn_sb *pfn_sb; - unsigned long npfns; phys_addr_t offset; const char *sig; u64 checksum; @@ -727,43 +686,35 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn) return -ENXIO; } - memset(pfn_sb, 0, sizeof(*pfn_sb)); - - trim_pfn_device(nd_pfn, &start_pad, &end_trunc); - if (start_pad + end_trunc) - dev_info(&nd_pfn->dev, "%s alignment collision, truncate %d bytes\n", - dev_name(&ndns->dev), start_pad + end_trunc); - /* * Note, we use 64 here for the standard size of struct page, * debugging options may cause it to be larger in which case the * implementation will limit the pfns advertised through * ->direct_access() to those that are included in the memmap. */ - start = nsio->res.start + start_pad; + start = nsio->res.start; size = resource_size(&nsio->res); - npfns = PFN_SECTION_ALIGN_UP((size - start_pad - end_trunc - reserve) - / PAGE_SIZE); + npfns = PHYS_PFN(size - SZ_8K); + align = max(nd_pfn->align, (1UL << SUBSECTION_SHIFT)); if (nd_pfn->mode == PFN_MODE_PMEM) { /* * The altmap should be padded out to the block size used * when populating the vmemmap. This *should* be equal to * PMD_SIZE for most architectures. */ - offset = ALIGN(start + reserve + 64 * npfns, - max(nd_pfn->align, PMD_SIZE)) - start; + offset = ALIGN(start + SZ_8K + 64 * npfns, align) - start; } else if (nd_pfn->mode == PFN_MODE_RAM) - offset = ALIGN(start + reserve, nd_pfn->align) - start; + offset = ALIGN(start + SZ_8K, align) - start; else return -ENXIO; - if (offset + start_pad + end_trunc >= size) { + if (offset >= size) { dev_err(&nd_pfn->dev, "%s unable to satisfy requested alignment\n", dev_name(&ndns->dev)); return -ENXIO; } - npfns = (size - offset - start_pad - end_trunc) / SZ_4K; + npfns = PHYS_PFN(size - offset); pfn_sb->mode = cpu_to_le32(nd_pfn->mode); pfn_sb->dataoff = cpu_to_le64(offset); pfn_sb->npfns = cpu_to_le64(npfns); @@ -772,8 +723,6 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn) memcpy(pfn_sb->parent_uuid, nd_dev_to_uuid(&ndns->dev), 16); pfn_sb->version_major = cpu_to_le16(1); pfn_sb->version_minor = cpu_to_le16(3); - pfn_sb->start_pad = cpu_to_le32(start_pad); - pfn_sb->end_trunc = cpu_to_le32(end_trunc); pfn_sb->align = cpu_to_le32(nd_pfn->align); checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb); pfn_sb->checksum = cpu_to_le64(checksum); diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 8331e76677c0..d77d717c620c 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1160,6 +1160,9 @@ static inline unsigned long section_nr_to_pfn(unsigned long sec) #define SUBSECTIONS_PER_SECTION (1UL << (SECTION_SIZE_BITS - SUBSECTION_SHIFT)) #endif +#define SUBSECTION_ALIGN_UP(pfn) ALIGN((pfn), PAGES_PER_SUBSECTION) +#define SUBSECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SUBSECTION_MASK) + struct mem_section_usage { DECLARE_BITMAP(subsection_map, SUBSECTIONS_PER_SECTION); /* See declaration of similar field in struct zone */ -- cgit v1.3-14-g43fede