From: Dan Williams <dan.j.williams@intel.com> To: akpm@linux-foundation.org Cc: Michal Hocko <mhocko@suse.com>, Pavel Tatashin <pasha.tatashin@soleen.com>, linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Vlastimil Babka <vbabka@suse.cz>, Oscar Salvador <osalvador@suse.de> Subject: [PATCH v10 09/13] mm/sparsemem: Support sub-section hotplug Date: Tue, 18 Jun 2019 22:52:23 -0700 [thread overview] Message-ID: <156092354368.979959.6232443923440952359.stgit@dwillia2-desk3.amr.corp.intel.com> (raw) In-Reply-To: <156092349300.979959.17603710711957735135.stgit@dwillia2-desk3.amr.corp.intel.com> The libnvdimm sub-system has suffered a series of hacks and broken workarounds for the memory-hotplug implementation's awkward section-aligned (128MB) granularity. For example the following backtrace is emitted when attempting arch_add_memory() with physical address ranges that intersect 'System RAM' (RAM) with 'Persistent Memory' (PMEM) within a given section: # cat /proc/iomem | grep -A1 -B1 Persistent\ Memory 100000000-1ffffffff : System RAM 200000000-303ffffff : Persistent Memory (legacy) 304000000-43fffffff : System RAM 440000000-23ffffffff : Persistent Memory 2400000000-43bfffffff : Persistent Memory 2400000000-43bfffffff : namespace2.0 WARNING: CPU: 38 PID: 928 at arch/x86/mm/init_64.c:850 add_pages+0x5c/0x60 [..] RIP: 0010:add_pages+0x5c/0x60 [..] Call Trace: devm_memremap_pages+0x460/0x6e0 pmem_attach_disk+0x29e/0x680 [nd_pmem] ? nd_dax_probe+0xfc/0x120 [libnvdimm] nvdimm_bus_probe+0x66/0x160 [libnvdimm] It was discovered that the problem goes beyond RAM vs PMEM collisions as some platform produce PMEM vs PMEM collisions within a given section. The libnvdimm workaround for that case revealed that the libnvdimm section-alignment-padding implementation has been broken for a long while. A fix for that long-standing breakage introduces as many problems as it solves as it would require a backward-incompatible change to the namespace metadata interpretation. Instead of that dubious route [1], address the root problem in the memory-hotplug implementation. Note that EEXIST is no longer treated as success as that is how sparse_add_section() reports subsection collisions, it was also obviated by recent changes to perform the request_region() for 'System RAM' before arch_add_memory() in the add_memory() sequence. [1]: https://lore.kernel.org/r/155000671719.348031.2347363160141119237.stgit@dwillia2-desk3.amr.corp.intel.com Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- include/linux/memory_hotplug.h | 2 mm/memory_hotplug.c | 27 +---- mm/page_alloc.c | 2 mm/sparse.c | 205 ++++++++++++++++++++++++++-------------- 4 files changed, 140 insertions(+), 96 deletions(-) diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 3ab0282b4fe5..0b8a5e5ef2da 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -350,7 +350,7 @@ extern void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn, extern bool is_memblock_offlined(struct memory_block *mem); extern int sparse_add_section(int nid, unsigned long pfn, unsigned long nr_pages, struct vmem_altmap *altmap); -extern void sparse_remove_one_section(struct mem_section *ms, +extern void sparse_remove_section(struct mem_section *ms, unsigned long pfn, unsigned long nr_pages, unsigned long map_offset, struct vmem_altmap *altmap); extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map, diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 399bf78bccc5..4e8e65954f31 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -252,18 +252,6 @@ void __init register_page_bootmem_info_node(struct pglist_data *pgdat) } #endif /* CONFIG_HAVE_BOOTMEM_INFO_NODE */ -static int __meminit __add_section(int nid, unsigned long pfn, - unsigned long nr_pages, struct vmem_altmap *altmap) -{ - int ret; - - if (pfn_valid(pfn)) - return -EEXIST; - - ret = sparse_add_section(nid, pfn, nr_pages, altmap); - return ret < 0 ? ret : 0; -} - static int check_pfn_span(unsigned long pfn, unsigned long nr_pages, const char *reason) { @@ -327,18 +315,11 @@ int __ref __add_pages(int nid, unsigned long pfn, unsigned long nr_pages, pfns = min(nr_pages, PAGES_PER_SECTION - (pfn & ~PAGE_SECTION_MASK)); - err = __add_section(nid, pfn, pfns, altmap); + err = sparse_add_section(nid, pfn, pfns, altmap); + if (err) + break; pfn += pfns; nr_pages -= pfns; - - /* - * EEXIST is finally dealt with by ioresource collision - * check. see add_memory() => register_memory_resource() - * Warning will be printed if there is collision. - */ - if (err && (err != -EEXIST)) - break; - err = 0; cond_resched(); } vmemmap_populate_print_last(); @@ -541,7 +522,7 @@ static void __remove_section(struct zone *zone, unsigned long pfn, return; __remove_zone(zone, pfn, nr_pages); - sparse_remove_one_section(ms, pfn, nr_pages, map_offset, altmap); + sparse_remove_section(ms, pfn, nr_pages, map_offset, altmap); } /** diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 12b2afd3a529..5b3266d63521 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5931,7 +5931,7 @@ void __ref memmap_init_zone_device(struct zone *zone, * pfn out of zone. * * Please note that MEMMAP_HOTPLUG path doesn't clear memmap - * because this is done early in sparse_add_one_section + * because this is done early in section_activate() */ if (!(pfn & (pageblock_nr_pages - 1))) { set_pageblock_migratetype(page, MIGRATE_MOVABLE); diff --git a/mm/sparse.c b/mm/sparse.c index ad47e25c8f94..b77ca21a27a4 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -83,8 +83,15 @@ static int __meminit sparse_index_init(unsigned long section_nr, int nid) unsigned long root = SECTION_NR_TO_ROOT(section_nr); struct mem_section *section; + /* + * An existing section is possible in the sub-section hotplug + * case. First hot-add instantiates, follow-on hot-add reuses + * the existing section. + * + * The mem_hotplug_lock resolves the apparent race below. + */ if (mem_section[root]) - return -EEXIST; + return 0; section = sparse_index_alloc(nid); if (!section) @@ -715,10 +722,119 @@ static void free_map_bootmem(struct page *memmap) } #endif /* CONFIG_SPARSEMEM_VMEMMAP */ +static void section_deactivate(unsigned long pfn, unsigned long nr_pages, + struct vmem_altmap *altmap) +{ + DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 }; + DECLARE_BITMAP(tmp, SUBSECTIONS_PER_SECTION) = { 0 }; + struct mem_section *ms = __pfn_to_section(pfn); + struct page *memmap = NULL; + unsigned long *subsection_map = ms->usage + ? &ms->usage->subsection_map[0] : NULL; + + subsection_mask_set(map, pfn, nr_pages); + if (subsection_map) + bitmap_and(tmp, map, subsection_map, SUBSECTIONS_PER_SECTION); + + if (WARN(!subsection_map || !bitmap_equal(tmp, map, SUBSECTIONS_PER_SECTION), + "section already deactivated (%#lx + %ld)\n", + pfn, nr_pages)) + return; + + /* + * There are 3 cases to handle across two configurations + * (SPARSEMEM_VMEMMAP={y,n}): + * + * 1/ deactivation of a partial hot-added section (only possible + * in the SPARSEMEM_VMEMMAP=y case). + * a/ section was present at memory init + * b/ section was hot-added post memory init + * 2/ deactivation of a complete hot-added section + * 3/ deactivation of a complete section from memory init + * + * For 1/, when subsection_map does not empty we will not be + * freeing the usage map, but still need to free the vmemmap + * range. + * + * For 2/ and 3/ the SPARSEMEM_VMEMMAP={y,n} cases are unified + */ + bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION); + if (bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION)) { + unsigned long section_nr = pfn_to_section_nr(pfn); + + if (!early_section(ms)) { + kfree(ms->usage); + ms->usage = NULL; + } + memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); + ms->section_mem_map = sparse_encode_mem_map(NULL, section_nr); + } + + if (early_section(ms) && memmap) + free_map_bootmem(memmap); + else + depopulate_section_memmap(pfn, nr_pages, altmap); +} + +static struct page * __meminit section_activate(int nid, unsigned long pfn, + unsigned long nr_pages, struct vmem_altmap *altmap) +{ + DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 }; + struct mem_section *ms = __pfn_to_section(pfn); + struct mem_section_usage *usage = NULL; + unsigned long *subsection_map; + struct page *memmap; + int rc = 0; + + subsection_mask_set(map, pfn, nr_pages); + + if (!ms->usage) { + usage = kzalloc(mem_section_usage_size(), GFP_KERNEL); + if (!usage) + return ERR_PTR(-ENOMEM); + ms->usage = usage; + } + subsection_map = &ms->usage->subsection_map[0]; + + if (bitmap_empty(map, SUBSECTIONS_PER_SECTION)) + rc = -EINVAL; + else if (bitmap_intersects(map, subsection_map, SUBSECTIONS_PER_SECTION)) + rc = -EEXIST; + else + bitmap_or(subsection_map, map, subsection_map, + SUBSECTIONS_PER_SECTION); + + if (rc) { + if (usage) + ms->usage = NULL; + kfree(usage); + return ERR_PTR(rc); + } + + /* + * The early init code does not consider partially populated + * initial sections, it simply assumes that memory will never be + * referenced. If we hot-add memory into such a section then we + * do not need to populate the memmap and can simply reuse what + * is already there. + */ + if (nr_pages < PAGES_PER_SECTION && early_section(ms)) + return pfn_to_page(pfn); + + memmap = populate_section_memmap(pfn, nr_pages, nid, altmap); + if (!memmap) { + section_deactivate(pfn, nr_pages, altmap); + return ERR_PTR(-ENOMEM); + } + + return memmap; +} + /** - * sparse_add_one_section - add a memory section + * sparse_add_section - add a memory section, or populate an existing one * @nid: The node to add section on * @start_pfn: start pfn of the memory range + * @nr_pages: number of pfns to add in the section * @altmap: device page map * * This is only intended for hotplug. @@ -732,50 +848,33 @@ int __meminit sparse_add_section(int nid, unsigned long start_pfn, unsigned long nr_pages, 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; int ret; - /* - * no locking for this, because it does its own - * plus, it does a kmalloc - */ ret = sparse_index_init(section_nr, nid); - if (ret < 0 && ret != -EEXIST) + if (ret < 0) return ret; - ret = 0; - memmap = populate_section_memmap(start_pfn, PAGES_PER_SECTION, nid, - altmap); - if (!memmap) - return -ENOMEM; - usage = kzalloc(mem_section_usage_size(), GFP_KERNEL); - if (!usage) { - depopulate_section_memmap(start_pfn, PAGES_PER_SECTION, altmap); - return -ENOMEM; - } - ms = __pfn_to_section(start_pfn); - if (ms->section_mem_map & SECTION_MARKED_PRESENT) { - ret = -EEXIST; - goto out; - } + memmap = section_activate(nid, start_pfn, nr_pages, altmap); + if (IS_ERR(memmap)) + return PTR_ERR(memmap); /* * Poison uninitialized struct pages in order to catch invalid flags * combinations. */ - page_init_poison(memmap, sizeof(struct page) * PAGES_PER_SECTION); + page_init_poison(pfn_to_page(start_pfn), sizeof(struct page) * nr_pages); + ms = __pfn_to_section(start_pfn); section_mark_present(ms); - sparse_init_one_section(ms, section_nr, memmap, usage, 0); -out: - if (ret < 0) { - kfree(usage); - depopulate_section_memmap(start_pfn, PAGES_PER_SECTION, altmap); - } - return ret; + /* Align memmap to section boundary in the subsection case */ + if (section_nr_to_pfn(section_nr) != start_pfn) + memmap = pfn_to_kaddr(section_nr_to_pfn(section_nr)); + sparse_init_one_section(ms, section_nr, memmap, ms->usage, 0); + + return 0; } #ifdef CONFIG_MEMORY_FAILURE @@ -808,48 +907,12 @@ static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages) } #endif -static void free_section_usage(struct mem_section *ms, struct page *memmap, - struct mem_section_usage *usage, unsigned long pfn, - unsigned long nr_pages, struct vmem_altmap *altmap) -{ - if (!usage) - return; - - /* - * Check to see if allocation came from hot-plug-add - */ - if (!early_section(ms)) { - kfree(usage); - if (memmap) - depopulate_section_memmap(pfn, nr_pages, altmap); - return; - } - - /* - * The usemap came from bootmem. This is packed with other usemaps - * on the section which has pgdat at boot time. Just keep it as is now. - */ - - if (memmap) - free_map_bootmem(memmap); -} - -void sparse_remove_one_section(struct mem_section *ms, unsigned long pfn, +void sparse_remove_section(struct mem_section *ms, unsigned long pfn, unsigned long nr_pages, unsigned long map_offset, struct vmem_altmap *altmap) { - struct page *memmap = NULL; - struct mem_section_usage *usage = NULL; - - if (ms->section_mem_map) { - usage = ms->usage; - memmap = sparse_decode_mem_map(ms->section_mem_map, - __section_nr(ms)); - ms->section_mem_map = 0; - ms->usage = NULL; - } - - clear_hwpoisoned_pages(memmap + map_offset, nr_pages - map_offset); - free_section_usage(ms, memmap, usage, pfn, nr_pages, altmap); + clear_hwpoisoned_pages(pfn_to_page(pfn) + map_offset, + nr_pages - map_offset); + section_deactivate(pfn, nr_pages, altmap); } #endif /* CONFIG_MEMORY_HOTPLUG */ _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm
WARNING: multiple messages have this Message-ID (diff)
From: Dan Williams <dan.j.williams@intel.com> To: akpm@linux-foundation.org Cc: Michal Hocko <mhocko@suse.com>, Vlastimil Babka <vbabka@suse.cz>, Logan Gunthorpe <logang@deltatee.com>, Oscar Salvador <osalvador@suse.de>, Pavel Tatashin <pasha.tatashin@soleen.com>, linux-mm@kvack.org, linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org Subject: [PATCH v10 09/13] mm/sparsemem: Support sub-section hotplug Date: Tue, 18 Jun 2019 22:52:23 -0700 [thread overview] Message-ID: <156092354368.979959.6232443923440952359.stgit@dwillia2-desk3.amr.corp.intel.com> (raw) In-Reply-To: <156092349300.979959.17603710711957735135.stgit@dwillia2-desk3.amr.corp.intel.com> The libnvdimm sub-system has suffered a series of hacks and broken workarounds for the memory-hotplug implementation's awkward section-aligned (128MB) granularity. For example the following backtrace is emitted when attempting arch_add_memory() with physical address ranges that intersect 'System RAM' (RAM) with 'Persistent Memory' (PMEM) within a given section: # cat /proc/iomem | grep -A1 -B1 Persistent\ Memory 100000000-1ffffffff : System RAM 200000000-303ffffff : Persistent Memory (legacy) 304000000-43fffffff : System RAM 440000000-23ffffffff : Persistent Memory 2400000000-43bfffffff : Persistent Memory 2400000000-43bfffffff : namespace2.0 WARNING: CPU: 38 PID: 928 at arch/x86/mm/init_64.c:850 add_pages+0x5c/0x60 [..] RIP: 0010:add_pages+0x5c/0x60 [..] Call Trace: devm_memremap_pages+0x460/0x6e0 pmem_attach_disk+0x29e/0x680 [nd_pmem] ? nd_dax_probe+0xfc/0x120 [libnvdimm] nvdimm_bus_probe+0x66/0x160 [libnvdimm] It was discovered that the problem goes beyond RAM vs PMEM collisions as some platform produce PMEM vs PMEM collisions within a given section. The libnvdimm workaround for that case revealed that the libnvdimm section-alignment-padding implementation has been broken for a long while. A fix for that long-standing breakage introduces as many problems as it solves as it would require a backward-incompatible change to the namespace metadata interpretation. Instead of that dubious route [1], address the root problem in the memory-hotplug implementation. Note that EEXIST is no longer treated as success as that is how sparse_add_section() reports subsection collisions, it was also obviated by recent changes to perform the request_region() for 'System RAM' before arch_add_memory() in the add_memory() sequence. [1]: https://lore.kernel.org/r/155000671719.348031.2347363160141119237.stgit@dwillia2-desk3.amr.corp.intel.com Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- include/linux/memory_hotplug.h | 2 mm/memory_hotplug.c | 27 +---- mm/page_alloc.c | 2 mm/sparse.c | 205 ++++++++++++++++++++++++++-------------- 4 files changed, 140 insertions(+), 96 deletions(-) diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 3ab0282b4fe5..0b8a5e5ef2da 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -350,7 +350,7 @@ extern void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn, extern bool is_memblock_offlined(struct memory_block *mem); extern int sparse_add_section(int nid, unsigned long pfn, unsigned long nr_pages, struct vmem_altmap *altmap); -extern void sparse_remove_one_section(struct mem_section *ms, +extern void sparse_remove_section(struct mem_section *ms, unsigned long pfn, unsigned long nr_pages, unsigned long map_offset, struct vmem_altmap *altmap); extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map, diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 399bf78bccc5..4e8e65954f31 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -252,18 +252,6 @@ void __init register_page_bootmem_info_node(struct pglist_data *pgdat) } #endif /* CONFIG_HAVE_BOOTMEM_INFO_NODE */ -static int __meminit __add_section(int nid, unsigned long pfn, - unsigned long nr_pages, struct vmem_altmap *altmap) -{ - int ret; - - if (pfn_valid(pfn)) - return -EEXIST; - - ret = sparse_add_section(nid, pfn, nr_pages, altmap); - return ret < 0 ? ret : 0; -} - static int check_pfn_span(unsigned long pfn, unsigned long nr_pages, const char *reason) { @@ -327,18 +315,11 @@ int __ref __add_pages(int nid, unsigned long pfn, unsigned long nr_pages, pfns = min(nr_pages, PAGES_PER_SECTION - (pfn & ~PAGE_SECTION_MASK)); - err = __add_section(nid, pfn, pfns, altmap); + err = sparse_add_section(nid, pfn, pfns, altmap); + if (err) + break; pfn += pfns; nr_pages -= pfns; - - /* - * EEXIST is finally dealt with by ioresource collision - * check. see add_memory() => register_memory_resource() - * Warning will be printed if there is collision. - */ - if (err && (err != -EEXIST)) - break; - err = 0; cond_resched(); } vmemmap_populate_print_last(); @@ -541,7 +522,7 @@ static void __remove_section(struct zone *zone, unsigned long pfn, return; __remove_zone(zone, pfn, nr_pages); - sparse_remove_one_section(ms, pfn, nr_pages, map_offset, altmap); + sparse_remove_section(ms, pfn, nr_pages, map_offset, altmap); } /** diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 12b2afd3a529..5b3266d63521 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5931,7 +5931,7 @@ void __ref memmap_init_zone_device(struct zone *zone, * pfn out of zone. * * Please note that MEMMAP_HOTPLUG path doesn't clear memmap - * because this is done early in sparse_add_one_section + * because this is done early in section_activate() */ if (!(pfn & (pageblock_nr_pages - 1))) { set_pageblock_migratetype(page, MIGRATE_MOVABLE); diff --git a/mm/sparse.c b/mm/sparse.c index ad47e25c8f94..b77ca21a27a4 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -83,8 +83,15 @@ static int __meminit sparse_index_init(unsigned long section_nr, int nid) unsigned long root = SECTION_NR_TO_ROOT(section_nr); struct mem_section *section; + /* + * An existing section is possible in the sub-section hotplug + * case. First hot-add instantiates, follow-on hot-add reuses + * the existing section. + * + * The mem_hotplug_lock resolves the apparent race below. + */ if (mem_section[root]) - return -EEXIST; + return 0; section = sparse_index_alloc(nid); if (!section) @@ -715,10 +722,119 @@ static void free_map_bootmem(struct page *memmap) } #endif /* CONFIG_SPARSEMEM_VMEMMAP */ +static void section_deactivate(unsigned long pfn, unsigned long nr_pages, + struct vmem_altmap *altmap) +{ + DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 }; + DECLARE_BITMAP(tmp, SUBSECTIONS_PER_SECTION) = { 0 }; + struct mem_section *ms = __pfn_to_section(pfn); + struct page *memmap = NULL; + unsigned long *subsection_map = ms->usage + ? &ms->usage->subsection_map[0] : NULL; + + subsection_mask_set(map, pfn, nr_pages); + if (subsection_map) + bitmap_and(tmp, map, subsection_map, SUBSECTIONS_PER_SECTION); + + if (WARN(!subsection_map || !bitmap_equal(tmp, map, SUBSECTIONS_PER_SECTION), + "section already deactivated (%#lx + %ld)\n", + pfn, nr_pages)) + return; + + /* + * There are 3 cases to handle across two configurations + * (SPARSEMEM_VMEMMAP={y,n}): + * + * 1/ deactivation of a partial hot-added section (only possible + * in the SPARSEMEM_VMEMMAP=y case). + * a/ section was present at memory init + * b/ section was hot-added post memory init + * 2/ deactivation of a complete hot-added section + * 3/ deactivation of a complete section from memory init + * + * For 1/, when subsection_map does not empty we will not be + * freeing the usage map, but still need to free the vmemmap + * range. + * + * For 2/ and 3/ the SPARSEMEM_VMEMMAP={y,n} cases are unified + */ + bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION); + if (bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION)) { + unsigned long section_nr = pfn_to_section_nr(pfn); + + if (!early_section(ms)) { + kfree(ms->usage); + ms->usage = NULL; + } + memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); + ms->section_mem_map = sparse_encode_mem_map(NULL, section_nr); + } + + if (early_section(ms) && memmap) + free_map_bootmem(memmap); + else + depopulate_section_memmap(pfn, nr_pages, altmap); +} + +static struct page * __meminit section_activate(int nid, unsigned long pfn, + unsigned long nr_pages, struct vmem_altmap *altmap) +{ + DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 }; + struct mem_section *ms = __pfn_to_section(pfn); + struct mem_section_usage *usage = NULL; + unsigned long *subsection_map; + struct page *memmap; + int rc = 0; + + subsection_mask_set(map, pfn, nr_pages); + + if (!ms->usage) { + usage = kzalloc(mem_section_usage_size(), GFP_KERNEL); + if (!usage) + return ERR_PTR(-ENOMEM); + ms->usage = usage; + } + subsection_map = &ms->usage->subsection_map[0]; + + if (bitmap_empty(map, SUBSECTIONS_PER_SECTION)) + rc = -EINVAL; + else if (bitmap_intersects(map, subsection_map, SUBSECTIONS_PER_SECTION)) + rc = -EEXIST; + else + bitmap_or(subsection_map, map, subsection_map, + SUBSECTIONS_PER_SECTION); + + if (rc) { + if (usage) + ms->usage = NULL; + kfree(usage); + return ERR_PTR(rc); + } + + /* + * The early init code does not consider partially populated + * initial sections, it simply assumes that memory will never be + * referenced. If we hot-add memory into such a section then we + * do not need to populate the memmap and can simply reuse what + * is already there. + */ + if (nr_pages < PAGES_PER_SECTION && early_section(ms)) + return pfn_to_page(pfn); + + memmap = populate_section_memmap(pfn, nr_pages, nid, altmap); + if (!memmap) { + section_deactivate(pfn, nr_pages, altmap); + return ERR_PTR(-ENOMEM); + } + + return memmap; +} + /** - * sparse_add_one_section - add a memory section + * sparse_add_section - add a memory section, or populate an existing one * @nid: The node to add section on * @start_pfn: start pfn of the memory range + * @nr_pages: number of pfns to add in the section * @altmap: device page map * * This is only intended for hotplug. @@ -732,50 +848,33 @@ int __meminit sparse_add_section(int nid, unsigned long start_pfn, unsigned long nr_pages, 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; int ret; - /* - * no locking for this, because it does its own - * plus, it does a kmalloc - */ ret = sparse_index_init(section_nr, nid); - if (ret < 0 && ret != -EEXIST) + if (ret < 0) return ret; - ret = 0; - memmap = populate_section_memmap(start_pfn, PAGES_PER_SECTION, nid, - altmap); - if (!memmap) - return -ENOMEM; - usage = kzalloc(mem_section_usage_size(), GFP_KERNEL); - if (!usage) { - depopulate_section_memmap(start_pfn, PAGES_PER_SECTION, altmap); - return -ENOMEM; - } - ms = __pfn_to_section(start_pfn); - if (ms->section_mem_map & SECTION_MARKED_PRESENT) { - ret = -EEXIST; - goto out; - } + memmap = section_activate(nid, start_pfn, nr_pages, altmap); + if (IS_ERR(memmap)) + return PTR_ERR(memmap); /* * Poison uninitialized struct pages in order to catch invalid flags * combinations. */ - page_init_poison(memmap, sizeof(struct page) * PAGES_PER_SECTION); + page_init_poison(pfn_to_page(start_pfn), sizeof(struct page) * nr_pages); + ms = __pfn_to_section(start_pfn); section_mark_present(ms); - sparse_init_one_section(ms, section_nr, memmap, usage, 0); -out: - if (ret < 0) { - kfree(usage); - depopulate_section_memmap(start_pfn, PAGES_PER_SECTION, altmap); - } - return ret; + /* Align memmap to section boundary in the subsection case */ + if (section_nr_to_pfn(section_nr) != start_pfn) + memmap = pfn_to_kaddr(section_nr_to_pfn(section_nr)); + sparse_init_one_section(ms, section_nr, memmap, ms->usage, 0); + + return 0; } #ifdef CONFIG_MEMORY_FAILURE @@ -808,48 +907,12 @@ static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages) } #endif -static void free_section_usage(struct mem_section *ms, struct page *memmap, - struct mem_section_usage *usage, unsigned long pfn, - unsigned long nr_pages, struct vmem_altmap *altmap) -{ - if (!usage) - return; - - /* - * Check to see if allocation came from hot-plug-add - */ - if (!early_section(ms)) { - kfree(usage); - if (memmap) - depopulate_section_memmap(pfn, nr_pages, altmap); - return; - } - - /* - * The usemap came from bootmem. This is packed with other usemaps - * on the section which has pgdat at boot time. Just keep it as is now. - */ - - if (memmap) - free_map_bootmem(memmap); -} - -void sparse_remove_one_section(struct mem_section *ms, unsigned long pfn, +void sparse_remove_section(struct mem_section *ms, unsigned long pfn, unsigned long nr_pages, unsigned long map_offset, struct vmem_altmap *altmap) { - struct page *memmap = NULL; - struct mem_section_usage *usage = NULL; - - if (ms->section_mem_map) { - usage = ms->usage; - memmap = sparse_decode_mem_map(ms->section_mem_map, - __section_nr(ms)); - ms->section_mem_map = 0; - ms->usage = NULL; - } - - clear_hwpoisoned_pages(memmap + map_offset, nr_pages - map_offset); - free_section_usage(ms, memmap, usage, pfn, nr_pages, altmap); + clear_hwpoisoned_pages(pfn_to_page(pfn) + map_offset, + nr_pages - map_offset); + section_deactivate(pfn, nr_pages, altmap); } #endif /* CONFIG_MEMORY_HOTPLUG */
next prev parent reply other threads:[~2019-06-19 6:06 UTC|newest] Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-06-19 5:51 [PATCH v10 00/13] mm: Sub-section memory hotplug support Dan Williams 2019-06-19 5:51 ` Dan Williams 2019-06-19 5:51 ` [PATCH v10 01/13] mm/sparsemem: Introduce struct mem_section_usage Dan Williams 2019-06-19 5:51 ` Dan Williams 2019-06-19 5:51 ` [PATCH v10 02/13] mm/sparsemem: Introduce a SECTION_IS_EARLY flag Dan Williams 2019-06-19 5:51 ` Dan Williams 2019-06-24 17:54 ` Oscar Salvador 2019-06-24 17:54 ` Oscar Salvador 2019-06-19 5:51 ` [PATCH v10 03/13] mm/sparsemem: Add helpers track active portions of a section at boot Dan Williams 2019-06-19 5:51 ` Dan Williams 2019-06-24 17:57 ` Oscar Salvador 2019-06-24 17:57 ` Oscar Salvador 2019-06-24 17:57 ` Oscar Salvador 2019-06-19 5:51 ` [PATCH v10 04/13] mm/hotplug: Prepare shrink_{zone, pgdat}_span for sub-section removal Dan Williams 2019-06-19 5:51 ` Dan Williams 2019-06-19 5:52 ` [PATCH v10 05/13] mm/sparsemem: Convert kmalloc_section_memmap() to populate_section_memmap() Dan Williams 2019-06-19 5:52 ` Dan Williams 2019-06-24 18:00 ` Oscar Salvador 2019-06-24 18:00 ` Oscar Salvador 2019-06-24 18:00 ` Oscar Salvador 2019-06-19 5:52 ` [PATCH v10 06/13] mm/hotplug: Kill is_dev_zone() usage in __remove_pages() Dan Williams 2019-06-19 5:52 ` Dan Williams 2019-06-19 5:52 ` [PATCH v10 07/13] mm: Kill is_dev_zone() helper Dan Williams 2019-06-19 5:52 ` Dan Williams 2019-06-19 5:52 ` [PATCH v10 08/13] mm/sparsemem: Prepare for sub-section ranges Dan Williams 2019-06-19 5:52 ` Dan Williams 2019-06-20 10:31 ` David Hildenbrand 2019-06-20 10:31 ` David Hildenbrand 2019-06-20 16:19 ` Dan Williams 2019-06-20 16:19 ` Dan Williams 2019-06-20 16:35 ` David Hildenbrand 2019-06-20 16:35 ` David Hildenbrand 2019-06-20 16:56 ` Dan Williams 2019-06-20 16:56 ` Dan Williams 2019-06-20 16:56 ` Dan Williams 2019-06-24 18:05 ` Oscar Salvador 2019-06-24 18:05 ` Oscar Salvador 2019-06-24 18:05 ` Oscar Salvador 2019-06-19 5:52 ` Dan Williams [this message] 2019-06-19 5:52 ` [PATCH v10 09/13] mm/sparsemem: Support sub-section hotplug Dan Williams 2019-06-24 20:45 ` Oscar Salvador 2019-06-24 20:45 ` Oscar Salvador 2019-06-24 20:45 ` Oscar Salvador 2019-06-19 5:52 ` [PATCH v10 10/13] mm: Document ZONE_DEVICE memory-model implications Dan Williams 2019-06-19 5:52 ` Dan Williams 2019-06-20 12:30 ` Mike Rapoport 2019-06-20 12:30 ` Mike Rapoport 2019-06-19 5:52 ` [PATCH v10 11/13] mm/devm_memremap_pages: Enable sub-section remap Dan Williams 2019-06-19 5:52 ` Dan Williams 2019-06-19 5:52 ` [PATCH v10 12/13] libnvdimm/pfn: Fix fsdax-mode namespace info-block zero-fields Dan Williams 2019-06-19 5:52 ` Dan Williams 2019-06-19 16:30 ` Aneesh Kumar K.V 2019-06-19 17:06 ` Dan Williams 2019-06-19 17:06 ` Dan Williams 2019-06-19 17:06 ` Dan Williams 2019-06-19 5:52 ` [PATCH v10 13/13] libnvdimm/pfn: Stop padding pmem namespaces to section alignment Dan Williams 2019-06-19 5:52 ` Dan Williams 2019-06-20 12:30 ` [PATCH v10 00/13] mm: Sub-section memory hotplug support Aneesh Kumar K.V 2019-06-20 12:30 ` Aneesh Kumar K.V 2019-06-20 16:30 ` Dan Williams 2019-06-20 16:30 ` Dan Williams 2019-06-20 17:00 ` Oscar Salvador 2019-06-20 17:00 ` Oscar Salvador
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=156092354368.979959.6232443923440952359.stgit@dwillia2-desk3.amr.corp.intel.com \ --to=dan.j.williams@intel.com \ --cc=akpm@linux-foundation.org \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-mm@kvack.org \ --cc=linux-nvdimm@lists.01.org \ --cc=mhocko@suse.com \ --cc=osalvador@suse.de \ --cc=pasha.tatashin@soleen.com \ --cc=vbabka@suse.cz \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.