From 257bea71582d895894201b604990a900df489103 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 15 Oct 2020 20:07:59 -0700 Subject: mm/page_alloc: simplify __offline_isolated_pages() offline_pages() is the only user. __offline_isolated_pages() never gets called with ranges that contain memory holes and we no longer care about the return value. Drop the return value handling and all pfn_valid() checks. Update the documentation. Signed-off-by: David Hildenbrand Signed-off-by: Andrew Morton Reviewed-by: Oscar Salvador Acked-by: Michal Hocko Cc: Wei Yang Cc: Baoquan He Cc: Pankaj Gupta Cc: Charan Teja Reddy Cc: Dan Williams Cc: Fenghua Yu Cc: Logan Gunthorpe Cc: "Matthew Wilcox (Oracle)" Cc: Mel Gorman Cc: Mel Gorman Cc: Michel Lespinasse Cc: Mike Rapoport Cc: Tony Luck Link: https://lkml.kernel.org/r/20200819175957.28465-5-david@redhat.com Signed-off-by: Linus Torvalds --- include/linux/memory_hotplug.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux/memory_hotplug.h') diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index c0faa7a30c46..76b314031f09 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -103,8 +103,8 @@ extern int online_pages(unsigned long pfn, unsigned long nr_pages, int online_type, int nid); extern struct zone *test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn); -extern unsigned long __offline_isolated_pages(unsigned long start_pfn, - unsigned long end_pfn); +extern void __offline_isolated_pages(unsigned long start_pfn, + unsigned long end_pfn); typedef void (*online_page_callback_t)(struct page *page, unsigned int order); -- cgit v1.2.3-71-gd317 From d882c0067d99d0f2add9a41628703cc99511a639 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 15 Oct 2020 20:08:19 -0700 Subject: mm: pass migratetype into memmap_init_zone() and move_pfn_range_to_zone() On the memory onlining path, we want to start with MIGRATE_ISOLATE, to un-isolate the pages after memory onlining is complete. Let's allow passing in the migratetype. Signed-off-by: David Hildenbrand Signed-off-by: Andrew Morton Reviewed-by: Oscar Salvador Acked-by: Michal Hocko Cc: Wei Yang Cc: Baoquan He Cc: Pankaj Gupta Cc: Tony Luck Cc: Fenghua Yu Cc: Logan Gunthorpe Cc: Dan Williams Cc: Mike Rapoport Cc: "Matthew Wilcox (Oracle)" Cc: Michel Lespinasse Cc: Charan Teja Reddy Cc: Mel Gorman Link: https://lkml.kernel.org/r/20200819175957.28465-10-david@redhat.com Signed-off-by: Linus Torvalds --- arch/ia64/mm/init.c | 4 ++-- include/linux/memory_hotplug.h | 3 ++- include/linux/mm.h | 2 +- mm/memory_hotplug.c | 11 ++++++++--- mm/memremap.c | 3 ++- mm/page_alloc.c | 21 ++++++++++++--------- 6 files changed, 27 insertions(+), 17 deletions(-) (limited to 'include/linux/memory_hotplug.h') diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c index d8686bf3ae2f..ef12e097f318 100644 --- a/arch/ia64/mm/init.c +++ b/arch/ia64/mm/init.c @@ -537,7 +537,7 @@ virtual_memmap_init(u64 start, u64 end, void *arg) if (map_start < map_end) memmap_init_zone((unsigned long)(map_end - map_start), args->nid, args->zone, page_to_pfn(map_start), - MEMINIT_EARLY, NULL); + MEMINIT_EARLY, NULL, MIGRATE_MOVABLE); return 0; } @@ -547,7 +547,7 @@ memmap_init (unsigned long size, int nid, unsigned long zone, { if (!vmem_map) { memmap_init_zone(size, nid, zone, start_pfn, - MEMINIT_EARLY, NULL); + MEMINIT_EARLY, NULL, MIGRATE_MOVABLE); } else { struct page *start; struct memmap_init_callback_data args; diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 76b314031f09..51a877fec8da 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -351,7 +351,8 @@ extern int add_memory_resource(int nid, struct resource *resource); extern int add_memory_driver_managed(int nid, u64 start, u64 size, const char *resource_name); extern void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn, - unsigned long nr_pages, struct vmem_altmap *altmap); + unsigned long nr_pages, + struct vmem_altmap *altmap, int migratetype); extern void remove_pfn_range_from_zone(struct zone *zone, unsigned long start_pfn, unsigned long nr_pages); diff --git a/include/linux/mm.h b/include/linux/mm.h index a9df46309e07..61a2633fcc7f 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2440,7 +2440,7 @@ extern int __meminit __early_pfn_to_nid(unsigned long pfn, extern void set_dma_reserve(unsigned long new_dma_reserve); extern void memmap_init_zone(unsigned long, int, unsigned long, unsigned long, - enum meminit_context, struct vmem_altmap *); + enum meminit_context, struct vmem_altmap *, int migratetype); extern void setup_per_zone_wmarks(void); extern int __meminit init_per_zone_wmark_min(void); extern void mem_init(void); diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 113edf95b908..bb30e99b7383 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -701,9 +701,14 @@ static void __meminit resize_pgdat_range(struct pglist_data *pgdat, unsigned lon * Associate the pfn range with the given zone, initializing the memmaps * and resizing the pgdat/zone data to span the added pages. After this * call, all affected pages are PG_reserved. + * + * All aligned pageblocks are initialized to the specified migratetype + * (usually MIGRATE_MOVABLE). Besides setting the migratetype, no related + * zone stats (e.g., nr_isolate_pageblock) are touched. */ void __ref move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn, - unsigned long nr_pages, struct vmem_altmap *altmap) + unsigned long nr_pages, + struct vmem_altmap *altmap, int migratetype) { struct pglist_data *pgdat = zone->zone_pgdat; int nid = pgdat->node_id; @@ -728,7 +733,7 @@ void __ref move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn, * are reserved so nobody should be touching them so we should be safe */ memmap_init_zone(nr_pages, nid, zone_idx(zone), start_pfn, - MEMINIT_HOTPLUG, altmap); + MEMINIT_HOTPLUG, altmap, migratetype); set_zone_contiguous(zone); } @@ -808,7 +813,7 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, /* associate pfn range with the zone */ zone = zone_for_pfn_range(online_type, nid, pfn, nr_pages); - move_pfn_range_to_zone(zone, pfn, nr_pages, NULL); + move_pfn_range_to_zone(zone, pfn, nr_pages, NULL, MIGRATE_MOVABLE); arg.start_pfn = pfn; arg.nr_pages = nr_pages; diff --git a/mm/memremap.c b/mm/memremap.c index 198083453182..73a206d0f645 100644 --- a/mm/memremap.c +++ b/mm/memremap.c @@ -266,7 +266,8 @@ static int pagemap_range(struct dev_pagemap *pgmap, struct mhp_params *params, zone = &NODE_DATA(nid)->node_zones[ZONE_DEVICE]; move_pfn_range_to_zone(zone, PHYS_PFN(range->start), - PHYS_PFN(range_len(range)), params->altmap); + PHYS_PFN(range_len(range)), params->altmap, + MIGRATE_MOVABLE); } mem_hotplug_done(); diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 7a99ed299443..f7f292f1d108 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5990,10 +5990,15 @@ overlap_memmap_init(unsigned long zone, unsigned long *pfn) * Initially all pages are reserved - free ones are freed * up by memblock_free_all() once the early boot process is * done. Non-atomic initialization, single-pass. + * + * All aligned pageblocks are initialized to the specified migratetype + * (usually MIGRATE_MOVABLE). Besides setting the migratetype, no related + * zone stats (e.g., nr_isolate_pageblock) are touched. */ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, - unsigned long start_pfn, enum meminit_context context, - struct vmem_altmap *altmap) + unsigned long start_pfn, + enum meminit_context context, + struct vmem_altmap *altmap, int migratetype) { unsigned long pfn, end_pfn = start_pfn + size; struct page *page; @@ -6037,14 +6042,12 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, __SetPageReserved(page); /* - * Mark the block movable so that blocks are reserved for - * movable at startup. This will force kernel allocations - * to reserve their blocks rather than leaking throughout - * the address space during boot when many long-lived - * kernel allocations are made. + * Usually, we want to mark the pageblock MIGRATE_MOVABLE, + * such that unmovable allocations won't be scattered all + * over the place during system boot. */ if (IS_ALIGNED(pfn, pageblock_nr_pages)) { - set_pageblock_migratetype(page, MIGRATE_MOVABLE); + set_pageblock_migratetype(page, migratetype); cond_resched(); } pfn++; @@ -6144,7 +6147,7 @@ void __meminit __weak memmap_init(unsigned long size, int nid, if (end_pfn > start_pfn) { size = end_pfn - start_pfn; memmap_init_zone(size, nid, zone, start_pfn, - MEMINIT_EARLY, NULL); + MEMINIT_EARLY, NULL, MIGRATE_MOVABLE); } } } -- cgit v1.2.3-71-gd317 From 3a0aaefe4134951b4e89feb873c457428154530c Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 15 Oct 2020 20:08:39 -0700 Subject: mm/memory_hotplug: guard more declarations by CONFIG_MEMORY_HOTPLUG MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We soon want to pass flags via a new type to add_memory() and friends. That revealed that we currently don't guard some declarations by CONFIG_MEMORY_HOTPLUG. While some definitions could be moved to different places, let's keep it minimal for now and use CONFIG_MEMORY_HOTPLUG for all functions only compiled with CONFIG_MEMORY_HOTPLUG. Wrap sparse_decode_mem_map() into CONFIG_MEMORY_HOTPLUG, it's only called from CONFIG_MEMORY_HOTPLUG code. While at it, remove allow_online_pfn_range(), which is no longer around, and mhp_notimplemented(), which is unused. Signed-off-by: David Hildenbrand Signed-off-by: Andrew Morton Cc: Michal Hocko Cc: Dan Williams Cc: Pankaj Gupta Cc: Baoquan He Cc: Wei Yang Cc: Anton Blanchard Cc: Ard Biesheuvel Cc: Benjamin Herrenschmidt Cc: Boris Ostrovsky Cc: Christian Borntraeger Cc: Dave Jiang Cc: Eric Biederman Cc: Greg Kroah-Hartman Cc: Haiyang Zhang Cc: Heiko Carstens Cc: Jason Gunthorpe Cc: Jason Wang Cc: Juergen Gross Cc: Julien Grall Cc: Kees Cook Cc: "K. Y. Srinivasan" Cc: Len Brown Cc: Leonardo Bras Cc: Libor Pechacek Cc: Michael Ellerman Cc: "Michael S. Tsirkin" Cc: Nathan Lynch Cc: "Oliver O'Halloran" Cc: Paul Mackerras Cc: Pingfan Liu Cc: "Rafael J. Wysocki" Cc: Roger Pau Monné Cc: Stefano Stabellini Cc: Stephen Hemminger Cc: Thomas Gleixner Cc: Vasily Gorbik Cc: Vishal Verma Cc: Wei Liu Link: https://lkml.kernel.org/r/20200911103459.10306-4-david@redhat.com Signed-off-by: Linus Torvalds --- include/linux/memory_hotplug.h | 12 +++--------- mm/sparse.c | 2 ++ 2 files changed, 5 insertions(+), 9 deletions(-) (limited to 'include/linux/memory_hotplug.h') diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 51a877fec8da..1504b4d5ae6c 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -247,13 +247,6 @@ static inline void zone_span_writelock(struct zone *zone) {} static inline void zone_span_writeunlock(struct zone *zone) {} static inline void zone_seqlock_init(struct zone *zone) {} -static inline int mhp_notimplemented(const char *func) -{ - printk(KERN_WARNING "%s() called, with CONFIG_MEMORY_HOTPLUG disabled\n", func); - dump_stack(); - return -ENOSYS; -} - static inline void register_page_bootmem_info_node(struct pglist_data *pgdat) { } @@ -344,6 +337,7 @@ static inline void __remove_memory(int nid, u64 start, u64 size) {} extern void set_zone_contiguous(struct zone *zone); extern void clear_zone_contiguous(struct zone *zone); +#ifdef CONFIG_MEMORY_HOTPLUG extern void __ref free_area_init_core_hotplug(int nid); extern int __add_memory(int nid, u64 start, u64 size); extern int add_memory(int nid, u64 start, u64 size); @@ -364,8 +358,8 @@ extern void sparse_remove_section(struct mem_section *ms, unsigned long map_offset, struct vmem_altmap *altmap); extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum); -extern bool allow_online_pfn_range(int nid, unsigned long pfn, unsigned long nr_pages, - int online_type); extern struct zone *zone_for_pfn_range(int online_type, int nid, unsigned start_pfn, unsigned long nr_pages); +#endif /* CONFIG_MEMORY_HOTPLUG */ + #endif /* __LINUX_MEMORY_HOTPLUG_H */ diff --git a/mm/sparse.c b/mm/sparse.c index b25ad8e64839..7bd23f9d6cef 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -312,6 +312,7 @@ static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long p return coded_mem_map; } +#ifdef CONFIG_MEMORY_HOTPLUG /* * Decode mem_map from the coded memmap */ @@ -321,6 +322,7 @@ struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pn coded_mem_map &= SECTION_MAP_MASK; return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum); } +#endif /* CONFIG_MEMORY_HOTPLUG */ static void __meminit sparse_init_one_section(struct mem_section *ms, unsigned long pnum, struct page *mem_map, -- cgit v1.2.3-71-gd317 From b6117199787c60539105d2de0d010146e8396fc3 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 15 Oct 2020 20:08:44 -0700 Subject: mm/memory_hotplug: prepare passing flags to add_memory() and friends MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We soon want to pass flags, e.g., to mark added System RAM resources. mergeable. Prepare for that. This patch is based on a similar patch by Oscar Salvador: https://lkml.kernel.org/r/20190625075227.15193-3-osalvador@suse.de Signed-off-by: David Hildenbrand Signed-off-by: Andrew Morton Reviewed-by: Juergen Gross # Xen related part Reviewed-by: Pankaj Gupta Acked-by: Wei Liu Cc: Michal Hocko Cc: Dan Williams Cc: Jason Gunthorpe Cc: Baoquan He Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: "Rafael J. Wysocki" Cc: Len Brown Cc: Greg Kroah-Hartman Cc: Vishal Verma Cc: Dave Jiang Cc: "K. Y. Srinivasan" Cc: Haiyang Zhang Cc: Stephen Hemminger Cc: Wei Liu Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Christian Borntraeger Cc: David Hildenbrand Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: Boris Ostrovsky Cc: Stefano Stabellini Cc: "Oliver O'Halloran" Cc: Pingfan Liu Cc: Nathan Lynch Cc: Libor Pechacek Cc: Anton Blanchard Cc: Leonardo Bras Cc: Ard Biesheuvel Cc: Eric Biederman Cc: Julien Grall Cc: Kees Cook Cc: Roger Pau Monné Cc: Thomas Gleixner Cc: Wei Yang Link: https://lkml.kernel.org/r/20200911103459.10306-5-david@redhat.com Signed-off-by: Linus Torvalds --- arch/powerpc/platforms/powernv/memtrace.c | 2 +- arch/powerpc/platforms/pseries/hotplug-memory.c | 2 +- drivers/acpi/acpi_memhotplug.c | 3 ++- drivers/base/memory.c | 3 ++- drivers/dax/kmem.c | 2 +- drivers/hv/hv_balloon.c | 2 +- drivers/s390/char/sclp_cmd.c | 2 +- drivers/virtio/virtio_mem.c | 2 +- drivers/xen/balloon.c | 2 +- include/linux/memory_hotplug.h | 16 ++++++++++++---- mm/memory_hotplug.c | 14 +++++++------- 11 files changed, 30 insertions(+), 20 deletions(-) (limited to 'include/linux/memory_hotplug.h') diff --git a/arch/powerpc/platforms/powernv/memtrace.c b/arch/powerpc/platforms/powernv/memtrace.c index 13b369d2cc45..6828108486f8 100644 --- a/arch/powerpc/platforms/powernv/memtrace.c +++ b/arch/powerpc/platforms/powernv/memtrace.c @@ -224,7 +224,7 @@ static int memtrace_online(void) ent->mem = 0; } - if (add_memory(ent->nid, ent->start, ent->size)) { + if (add_memory(ent->nid, ent->start, ent->size, MHP_NONE)) { pr_err("Failed to add trace memory to node %d\n", ent->nid); ret += 1; diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c index 5d545b78111f..d8bbf0cc1601 100644 --- a/arch/powerpc/platforms/pseries/hotplug-memory.c +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c @@ -606,7 +606,7 @@ static int dlpar_add_lmb(struct drmem_lmb *lmb) block_sz = memory_block_size_bytes(); /* Add the memory */ - rc = __add_memory(lmb->nid, lmb->base_addr, block_sz); + rc = __add_memory(lmb->nid, lmb->base_addr, block_sz, MHP_NONE); if (rc) { invalidate_lmb_associativity_index(lmb); return rc; diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c index ad6e90fbc813..b02fd51e5589 100644 --- a/drivers/acpi/acpi_memhotplug.c +++ b/drivers/acpi/acpi_memhotplug.c @@ -194,7 +194,8 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device) if (node < 0) node = memory_add_physaddr_to_nid(info->start_addr); - result = __add_memory(node, info->start_addr, info->length); + result = __add_memory(node, info->start_addr, info->length, + MHP_NONE); /* * If the memory block has been used by the kernel, add_memory() diff --git a/drivers/base/memory.c b/drivers/base/memory.c index adf828dfccf0..eef4ffb6122c 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -432,7 +432,8 @@ static ssize_t probe_store(struct device *dev, struct device_attribute *attr, nid = memory_add_physaddr_to_nid(phys_addr); ret = __add_memory(nid, phys_addr, - MIN_MEMORY_BLOCK_SIZE * sections_per_block); + MIN_MEMORY_BLOCK_SIZE * sections_per_block, + MHP_NONE); if (ret) goto out; diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c index af04b6d1d263..b4368c5b6a0c 100644 --- a/drivers/dax/kmem.c +++ b/drivers/dax/kmem.c @@ -109,7 +109,7 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax) * this as RAM automatically. */ rc = add_memory_driver_managed(numa_node, range.start, - range_len(&range), kmem_name); + range_len(&range), kmem_name, MHP_NONE); if (rc) { dev_warn(dev, "mapping%d: %#llx-%#llx memory add failed\n", diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c index 32e3bc0aa665..3c0d52e24452 100644 --- a/drivers/hv/hv_balloon.c +++ b/drivers/hv/hv_balloon.c @@ -726,7 +726,7 @@ static void hv_mem_hot_add(unsigned long start, unsigned long size, nid = memory_add_physaddr_to_nid(PFN_PHYS(start_pfn)); ret = add_memory(nid, PFN_PHYS((start_pfn)), - (HA_CHUNK << PAGE_SHIFT)); + (HA_CHUNK << PAGE_SHIFT), MHP_NONE); if (ret) { pr_err("hot_add memory failed error is %d\n", ret); diff --git a/drivers/s390/char/sclp_cmd.c b/drivers/s390/char/sclp_cmd.c index a864b21af602..f6e97f0830f6 100644 --- a/drivers/s390/char/sclp_cmd.c +++ b/drivers/s390/char/sclp_cmd.c @@ -406,7 +406,7 @@ static void __init add_memory_merged(u16 rn) if (!size) goto skip_add; for (addr = start; addr < start + size; addr += block_size) - add_memory(0, addr, block_size); + add_memory(0, addr, block_size, MHP_NONE); skip_add: first_rn = rn; num = 1; diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c index 834b7c13ef3d..ed99e4335401 100644 --- a/drivers/virtio/virtio_mem.c +++ b/drivers/virtio/virtio_mem.c @@ -424,7 +424,7 @@ static int virtio_mem_mb_add(struct virtio_mem *vm, unsigned long mb_id) dev_dbg(&vm->vdev->dev, "adding memory block: %lu\n", mb_id); return add_memory_driver_managed(nid, addr, memory_block_size_bytes(), - vm->resource_name); + vm->resource_name, MHP_NONE); } /* diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index 51427c752b37..9f40a294d398 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -331,7 +331,7 @@ static enum bp_state reserve_additional_memory(void) mutex_unlock(&balloon_mutex); /* add_memory_resource() requires the device_hotplug lock */ lock_device_hotplug(); - rc = add_memory_resource(nid, resource); + rc = add_memory_resource(nid, resource, MHP_NONE); unlock_device_hotplug(); mutex_lock(&balloon_mutex); diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 1504b4d5ae6c..33eb80fdba22 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -57,6 +57,12 @@ enum { MMOP_ONLINE_MOVABLE, }; +/* Flags for add_memory() and friends to specify memory hotplug details. */ +typedef int __bitwise mhp_t; + +/* No special request */ +#define MHP_NONE ((__force mhp_t)0) + /* * Extended parameters for memory hotplug: * altmap: alternative allocator for memmap array (optional) @@ -339,11 +345,13 @@ extern void clear_zone_contiguous(struct zone *zone); #ifdef CONFIG_MEMORY_HOTPLUG extern void __ref free_area_init_core_hotplug(int nid); -extern int __add_memory(int nid, u64 start, u64 size); -extern int add_memory(int nid, u64 start, u64 size); -extern int add_memory_resource(int nid, struct resource *resource); +extern int __add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags); +extern int add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags); +extern int add_memory_resource(int nid, struct resource *resource, + mhp_t mhp_flags); extern int add_memory_driver_managed(int nid, u64 start, u64 size, - const char *resource_name); + const char *resource_name, + mhp_t mhp_flags); extern void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn, unsigned long nr_pages, struct vmem_altmap *altmap, int migratetype); diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 9a7193970e77..dba71bc34daa 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1039,7 +1039,7 @@ static int online_memory_block(struct memory_block *mem, void *arg) * * we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ -int __ref add_memory_resource(int nid, struct resource *res) +int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags) { struct mhp_params params = { .pgprot = PAGE_KERNEL }; u64 start, size; @@ -1119,7 +1119,7 @@ error: } /* requires device_hotplug_lock, see add_memory_resource() */ -int __ref __add_memory(int nid, u64 start, u64 size) +int __ref __add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags) { struct resource *res; int ret; @@ -1128,18 +1128,18 @@ int __ref __add_memory(int nid, u64 start, u64 size) if (IS_ERR(res)) return PTR_ERR(res); - ret = add_memory_resource(nid, res); + ret = add_memory_resource(nid, res, mhp_flags); if (ret < 0) release_memory_resource(res); return ret; } -int add_memory(int nid, u64 start, u64 size) +int add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags) { int rc; lock_device_hotplug(); - rc = __add_memory(nid, start, size); + rc = __add_memory(nid, start, size, mhp_flags); unlock_device_hotplug(); return rc; @@ -1168,7 +1168,7 @@ EXPORT_SYMBOL_GPL(add_memory); * "System RAM ($DRIVER)". */ int add_memory_driver_managed(int nid, u64 start, u64 size, - const char *resource_name) + const char *resource_name, mhp_t mhp_flags) { struct resource *res; int rc; @@ -1186,7 +1186,7 @@ int add_memory_driver_managed(int nid, u64 start, u64 size, goto out_unlock; } - rc = add_memory_resource(nid, res); + rc = add_memory_resource(nid, res, mhp_flags); if (rc < 0) release_memory_resource(res); -- cgit v1.2.3-71-gd317 From 9ca6551ee24368a4d2b09566ea4d10fe87860379 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 15 Oct 2020 20:08:49 -0700 Subject: mm/memory_hotplug: MEMHP_MERGE_RESOURCE to specify merging of System RAM resources MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Some add_memory*() users add memory in small, contiguous memory blocks. Examples include virtio-mem, hyper-v balloon, and the XEN balloon. This can quickly result in a lot of memory resources, whereby the actual resource boundaries are not of interest (e.g., it might be relevant for DIMMs, exposed via /proc/iomem to user space). We really want to merge added resources in this scenario where possible. Let's provide a flag (MEMHP_MERGE_RESOURCE) to specify that a resource either created within add_memory*() or passed via add_memory_resource() shall be marked mergeable and merged with applicable siblings. To implement that, we need a kernel/resource interface to mark selected System RAM resources mergeable (IORESOURCE_SYSRAM_MERGEABLE) and trigger merging. Note: We really want to merge after the whole operation succeeded, not directly when adding a resource to the resource tree (it would break add_memory_resource() and require splitting resources again when the operation failed - e.g., due to -ENOMEM). Signed-off-by: David Hildenbrand Signed-off-by: Andrew Morton Reviewed-by: Pankaj Gupta Cc: Michal Hocko Cc: Dan Williams Cc: Jason Gunthorpe Cc: Kees Cook Cc: Ard Biesheuvel Cc: Thomas Gleixner Cc: "K. Y. Srinivasan" Cc: Haiyang Zhang Cc: Stephen Hemminger Cc: Wei Liu Cc: Boris Ostrovsky Cc: Juergen Gross Cc: Stefano Stabellini Cc: Roger Pau Monné Cc: Julien Grall Cc: Baoquan He Cc: Wei Yang Cc: Anton Blanchard Cc: Benjamin Herrenschmidt Cc: Christian Borntraeger Cc: Dave Jiang Cc: Eric Biederman Cc: Greg Kroah-Hartman Cc: Heiko Carstens Cc: Jason Wang Cc: Len Brown Cc: Leonardo Bras Cc: Libor Pechacek Cc: Michael Ellerman Cc: "Michael S. Tsirkin" Cc: Nathan Lynch Cc: "Oliver O'Halloran" Cc: Paul Mackerras Cc: Pingfan Liu Cc: "Rafael J. Wysocki" Cc: Vasily Gorbik Cc: Vishal Verma Link: https://lkml.kernel.org/r/20200911103459.10306-6-david@redhat.com Signed-off-by: Linus Torvalds --- include/linux/ioport.h | 4 +++ include/linux/memory_hotplug.h | 7 +++++ kernel/resource.c | 60 ++++++++++++++++++++++++++++++++++++++++++ mm/memory_hotplug.c | 7 +++++ 4 files changed, 78 insertions(+) (limited to 'include/linux/memory_hotplug.h') diff --git a/include/linux/ioport.h b/include/linux/ioport.h index d7620d7c941a..7e61389dcb01 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -60,6 +60,7 @@ struct resource { /* IORESOURCE_SYSRAM specific bits. */ #define IORESOURCE_SYSRAM_DRIVER_MANAGED 0x02000000 /* Always detected via a driver. */ +#define IORESOURCE_SYSRAM_MERGEABLE 0x04000000 /* Resource can be merged. */ #define IORESOURCE_EXCLUSIVE 0x08000000 /* Userland may not map this resource */ @@ -253,6 +254,9 @@ extern void __release_region(struct resource *, resource_size_t, extern void release_mem_region_adjustable(struct resource *, resource_size_t, resource_size_t); #endif +#ifdef CONFIG_MEMORY_HOTPLUG +extern void merge_system_ram_resource(struct resource *res); +#endif /* Wrappers for managed devices */ struct device; diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 33eb80fdba22..d65c6fdc5cfc 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -62,6 +62,13 @@ typedef int __bitwise mhp_t; /* No special request */ #define MHP_NONE ((__force mhp_t)0) +/* + * Allow merging of the added System RAM resource with adjacent, + * mergeable resources. After a successful call to add_memory_resource() + * with this flag set, the resource pointer must no longer be used as it + * might be stale, or the resource might have changed. + */ +#define MEMHP_MERGE_RESOURCE ((__force mhp_t)BIT(0)) /* * Extended parameters for memory hotplug: diff --git a/kernel/resource.c b/kernel/resource.c index 4c1c487abbfb..92026827d95b 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -1363,6 +1363,66 @@ retry: } #endif /* CONFIG_MEMORY_HOTREMOVE */ +#ifdef CONFIG_MEMORY_HOTPLUG +static bool system_ram_resources_mergeable(struct resource *r1, + struct resource *r2) +{ + /* We assume either r1 or r2 is IORESOURCE_SYSRAM_MERGEABLE. */ + return r1->flags == r2->flags && r1->end + 1 == r2->start && + r1->name == r2->name && r1->desc == r2->desc && + !r1->child && !r2->child; +} + +/* + * merge_system_ram_resource - mark the System RAM resource mergeable and try to + * merge it with adjacent, mergeable resources + * @res: resource descriptor + * + * This interface is intended for memory hotplug, whereby lots of contiguous + * system ram resources are added (e.g., via add_memory*()) by a driver, and + * the actual resource boundaries are not of interest (e.g., it might be + * relevant for DIMMs). Only resources that are marked mergeable, that have the + * same parent, and that don't have any children are considered. All mergeable + * resources must be immutable during the request. + * + * Note: + * - The caller has to make sure that no pointers to resources that are + * marked mergeable are used anymore after this call - the resource might + * be freed and the pointer might be stale! + * - release_mem_region_adjustable() will split on demand on memory hotunplug + */ +void merge_system_ram_resource(struct resource *res) +{ + const unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; + struct resource *cur; + + if (WARN_ON_ONCE((res->flags & flags) != flags)) + return; + + write_lock(&resource_lock); + res->flags |= IORESOURCE_SYSRAM_MERGEABLE; + + /* Try to merge with next item in the list. */ + cur = res->sibling; + if (cur && system_ram_resources_mergeable(res, cur)) { + res->end = cur->end; + res->sibling = cur->sibling; + free_resource(cur); + } + + /* Try to merge with previous item in the list. */ + cur = res->parent->child; + while (cur && cur->sibling != res) + cur = cur->sibling; + if (cur && system_ram_resources_mergeable(cur, res)) { + cur->end = res->end; + cur->sibling = res->sibling; + free_resource(res); + } + write_unlock(&resource_lock); +} +#endif /* CONFIG_MEMORY_HOTPLUG */ + /* * Managed region resource */ diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index dba71bc34daa..dc7d82ece6cb 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1103,6 +1103,13 @@ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags) /* device_online() will take the lock when calling online_pages() */ mem_hotplug_done(); + /* + * In case we're allowed to merge the resource, flag it and trigger + * merging now that adding succeeded. + */ + if (mhp_flags & MEMHP_MERGE_RESOURCE) + merge_system_ram_resource(res); + /* online pages if requested */ if (memhp_default_online_type != MMOP_OFFLINE) walk_memory_blocks(start, size, NULL, online_memory_block); -- cgit v1.2.3-71-gd317