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908eedc616
Originally, walk_memory_resource() was introduced to traverse all memory of "System RAM" for detecting memory hotplug/unplug range. For doing so, flags of IORESOUCE_MEM|IORESOURCE_BUSY was used and this was enough for memory hotplug. But for using other purpose, /proc/kcore, this may includes some firmware area marked as IORESOURCE_BUSY | IORESOUCE_MEM. This patch makes the check strict to find out busy "System RAM". Note: PPC64 keeps their own walk_memory_resouce(), which walk through ppc64's lmb informaton. Because old kclist_add() is called per lmb, this patch makes no difference in behavior, finally. And this patch removes CONFIG_MEMORY_HOTPLUG check from this function. Because pfn_valid() just show "there is memmap or not* and cannot be used for "there is physical memory or not", this function is useful in generic to scan physical memory range. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: WANG Cong <xiyou.wangcong@gmail.com> Cc: Américo Wang <xiyou.wangcong@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
873 lines
21 KiB
C
873 lines
21 KiB
C
/*
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* linux/mm/memory_hotplug.c
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*
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* Copyright (C)
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*/
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#include <linux/stddef.h>
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#include <linux/mm.h>
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#include <linux/swap.h>
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#include <linux/interrupt.h>
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#include <linux/pagemap.h>
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#include <linux/bootmem.h>
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#include <linux/compiler.h>
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#include <linux/module.h>
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#include <linux/pagevec.h>
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#include <linux/writeback.h>
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#include <linux/slab.h>
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#include <linux/sysctl.h>
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#include <linux/cpu.h>
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#include <linux/memory.h>
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#include <linux/memory_hotplug.h>
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#include <linux/highmem.h>
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#include <linux/vmalloc.h>
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#include <linux/ioport.h>
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#include <linux/delay.h>
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#include <linux/migrate.h>
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#include <linux/page-isolation.h>
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#include <linux/pfn.h>
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#include <asm/tlbflush.h>
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#include "internal.h"
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/* add this memory to iomem resource */
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static struct resource *register_memory_resource(u64 start, u64 size)
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{
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struct resource *res;
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res = kzalloc(sizeof(struct resource), GFP_KERNEL);
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BUG_ON(!res);
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res->name = "System RAM";
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res->start = start;
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res->end = start + size - 1;
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res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
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if (request_resource(&iomem_resource, res) < 0) {
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printk("System RAM resource %llx - %llx cannot be added\n",
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(unsigned long long)res->start, (unsigned long long)res->end);
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kfree(res);
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res = NULL;
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}
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return res;
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}
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static void release_memory_resource(struct resource *res)
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{
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if (!res)
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return;
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release_resource(res);
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kfree(res);
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return;
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}
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#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
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#ifndef CONFIG_SPARSEMEM_VMEMMAP
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static void get_page_bootmem(unsigned long info, struct page *page, int type)
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{
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atomic_set(&page->_mapcount, type);
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SetPagePrivate(page);
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set_page_private(page, info);
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atomic_inc(&page->_count);
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}
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void put_page_bootmem(struct page *page)
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{
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int type;
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type = atomic_read(&page->_mapcount);
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BUG_ON(type >= -1);
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if (atomic_dec_return(&page->_count) == 1) {
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ClearPagePrivate(page);
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set_page_private(page, 0);
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reset_page_mapcount(page);
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__free_pages_bootmem(page, 0);
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}
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}
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static void register_page_bootmem_info_section(unsigned long start_pfn)
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{
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unsigned long *usemap, mapsize, section_nr, i;
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struct mem_section *ms;
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struct page *page, *memmap;
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if (!pfn_valid(start_pfn))
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return;
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section_nr = pfn_to_section_nr(start_pfn);
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ms = __nr_to_section(section_nr);
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/* Get section's memmap address */
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memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
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/*
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* Get page for the memmap's phys address
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* XXX: need more consideration for sparse_vmemmap...
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*/
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page = virt_to_page(memmap);
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mapsize = sizeof(struct page) * PAGES_PER_SECTION;
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mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT;
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/* remember memmap's page */
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for (i = 0; i < mapsize; i++, page++)
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get_page_bootmem(section_nr, page, SECTION_INFO);
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usemap = __nr_to_section(section_nr)->pageblock_flags;
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page = virt_to_page(usemap);
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mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT;
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for (i = 0; i < mapsize; i++, page++)
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get_page_bootmem(section_nr, page, MIX_SECTION_INFO);
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}
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void register_page_bootmem_info_node(struct pglist_data *pgdat)
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{
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unsigned long i, pfn, end_pfn, nr_pages;
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int node = pgdat->node_id;
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struct page *page;
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struct zone *zone;
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nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT;
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page = virt_to_page(pgdat);
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for (i = 0; i < nr_pages; i++, page++)
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get_page_bootmem(node, page, NODE_INFO);
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zone = &pgdat->node_zones[0];
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for (; zone < pgdat->node_zones + MAX_NR_ZONES - 1; zone++) {
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if (zone->wait_table) {
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nr_pages = zone->wait_table_hash_nr_entries
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* sizeof(wait_queue_head_t);
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nr_pages = PAGE_ALIGN(nr_pages) >> PAGE_SHIFT;
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page = virt_to_page(zone->wait_table);
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for (i = 0; i < nr_pages; i++, page++)
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get_page_bootmem(node, page, NODE_INFO);
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}
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}
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pfn = pgdat->node_start_pfn;
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end_pfn = pfn + pgdat->node_spanned_pages;
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/* register_section info */
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for (; pfn < end_pfn; pfn += PAGES_PER_SECTION)
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register_page_bootmem_info_section(pfn);
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}
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#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
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static void grow_zone_span(struct zone *zone, unsigned long start_pfn,
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unsigned long end_pfn)
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{
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unsigned long old_zone_end_pfn;
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zone_span_writelock(zone);
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old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages;
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if (start_pfn < zone->zone_start_pfn)
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zone->zone_start_pfn = start_pfn;
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zone->spanned_pages = max(old_zone_end_pfn, end_pfn) -
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zone->zone_start_pfn;
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zone_span_writeunlock(zone);
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}
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static void grow_pgdat_span(struct pglist_data *pgdat, unsigned long start_pfn,
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unsigned long end_pfn)
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{
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unsigned long old_pgdat_end_pfn =
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pgdat->node_start_pfn + pgdat->node_spanned_pages;
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if (start_pfn < pgdat->node_start_pfn)
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pgdat->node_start_pfn = start_pfn;
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pgdat->node_spanned_pages = max(old_pgdat_end_pfn, end_pfn) -
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pgdat->node_start_pfn;
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}
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static int __meminit __add_zone(struct zone *zone, unsigned long phys_start_pfn)
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{
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struct pglist_data *pgdat = zone->zone_pgdat;
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int nr_pages = PAGES_PER_SECTION;
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int nid = pgdat->node_id;
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int zone_type;
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unsigned long flags;
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zone_type = zone - pgdat->node_zones;
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if (!zone->wait_table) {
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int ret;
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ret = init_currently_empty_zone(zone, phys_start_pfn,
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nr_pages, MEMMAP_HOTPLUG);
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if (ret)
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return ret;
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}
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pgdat_resize_lock(zone->zone_pgdat, &flags);
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grow_zone_span(zone, phys_start_pfn, phys_start_pfn + nr_pages);
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grow_pgdat_span(zone->zone_pgdat, phys_start_pfn,
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phys_start_pfn + nr_pages);
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pgdat_resize_unlock(zone->zone_pgdat, &flags);
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memmap_init_zone(nr_pages, nid, zone_type,
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phys_start_pfn, MEMMAP_HOTPLUG);
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return 0;
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}
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static int __meminit __add_section(int nid, struct zone *zone,
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unsigned long phys_start_pfn)
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{
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int nr_pages = PAGES_PER_SECTION;
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int ret;
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if (pfn_valid(phys_start_pfn))
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return -EEXIST;
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ret = sparse_add_one_section(zone, phys_start_pfn, nr_pages);
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if (ret < 0)
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return ret;
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ret = __add_zone(zone, phys_start_pfn);
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if (ret < 0)
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return ret;
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return register_new_memory(nid, __pfn_to_section(phys_start_pfn));
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}
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#ifdef CONFIG_SPARSEMEM_VMEMMAP
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static int __remove_section(struct zone *zone, struct mem_section *ms)
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{
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/*
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* XXX: Freeing memmap with vmemmap is not implement yet.
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* This should be removed later.
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*/
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return -EBUSY;
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}
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#else
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static int __remove_section(struct zone *zone, struct mem_section *ms)
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{
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unsigned long flags;
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struct pglist_data *pgdat = zone->zone_pgdat;
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int ret = -EINVAL;
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if (!valid_section(ms))
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return ret;
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ret = unregister_memory_section(ms);
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if (ret)
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return ret;
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pgdat_resize_lock(pgdat, &flags);
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sparse_remove_one_section(zone, ms);
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pgdat_resize_unlock(pgdat, &flags);
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return 0;
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}
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#endif
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/*
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* Reasonably generic function for adding memory. It is
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* expected that archs that support memory hotplug will
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* call this function after deciding the zone to which to
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* add the new pages.
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*/
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int __ref __add_pages(int nid, struct zone *zone, unsigned long phys_start_pfn,
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unsigned long nr_pages)
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{
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unsigned long i;
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int err = 0;
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int start_sec, end_sec;
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/* during initialize mem_map, align hot-added range to section */
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start_sec = pfn_to_section_nr(phys_start_pfn);
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end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1);
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for (i = start_sec; i <= end_sec; i++) {
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err = __add_section(nid, zone, i << PFN_SECTION_SHIFT);
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/*
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* EEXIST is finally dealt with by ioresource collision
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* check. see add_memory() => register_memory_resource()
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* Warning will be printed if there is collision.
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*/
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if (err && (err != -EEXIST))
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break;
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err = 0;
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}
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return err;
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}
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EXPORT_SYMBOL_GPL(__add_pages);
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/**
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* __remove_pages() - remove sections of pages from a zone
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* @zone: zone from which pages need to be removed
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* @phys_start_pfn: starting pageframe (must be aligned to start of a section)
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* @nr_pages: number of pages to remove (must be multiple of section size)
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*
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* Generic helper function to remove section mappings and sysfs entries
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* for the section of the memory we are removing. Caller needs to make
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* sure that pages are marked reserved and zones are adjust properly by
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* calling offline_pages().
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*/
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int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
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unsigned long nr_pages)
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{
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unsigned long i, ret = 0;
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int sections_to_remove;
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/*
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* We can only remove entire sections
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*/
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BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK);
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BUG_ON(nr_pages % PAGES_PER_SECTION);
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sections_to_remove = nr_pages / PAGES_PER_SECTION;
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for (i = 0; i < sections_to_remove; i++) {
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unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION;
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release_mem_region(pfn << PAGE_SHIFT,
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PAGES_PER_SECTION << PAGE_SHIFT);
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ret = __remove_section(zone, __pfn_to_section(pfn));
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if (ret)
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break;
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}
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return ret;
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}
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EXPORT_SYMBOL_GPL(__remove_pages);
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void online_page(struct page *page)
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{
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unsigned long pfn = page_to_pfn(page);
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totalram_pages++;
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if (pfn >= num_physpages)
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num_physpages = pfn + 1;
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#ifdef CONFIG_HIGHMEM
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if (PageHighMem(page))
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totalhigh_pages++;
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#endif
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#ifdef CONFIG_FLATMEM
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max_mapnr = max(page_to_pfn(page), max_mapnr);
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#endif
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ClearPageReserved(page);
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init_page_count(page);
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__free_page(page);
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}
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static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
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void *arg)
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{
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unsigned long i;
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unsigned long onlined_pages = *(unsigned long *)arg;
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struct page *page;
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if (PageReserved(pfn_to_page(start_pfn)))
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for (i = 0; i < nr_pages; i++) {
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page = pfn_to_page(start_pfn + i);
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online_page(page);
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onlined_pages++;
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}
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*(unsigned long *)arg = onlined_pages;
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return 0;
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}
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int online_pages(unsigned long pfn, unsigned long nr_pages)
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{
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unsigned long onlined_pages = 0;
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struct zone *zone;
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int need_zonelists_rebuild = 0;
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int nid;
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int ret;
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struct memory_notify arg;
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arg.start_pfn = pfn;
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arg.nr_pages = nr_pages;
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arg.status_change_nid = -1;
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nid = page_to_nid(pfn_to_page(pfn));
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if (node_present_pages(nid) == 0)
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arg.status_change_nid = nid;
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ret = memory_notify(MEM_GOING_ONLINE, &arg);
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ret = notifier_to_errno(ret);
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if (ret) {
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memory_notify(MEM_CANCEL_ONLINE, &arg);
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return ret;
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}
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/*
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* This doesn't need a lock to do pfn_to_page().
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* The section can't be removed here because of the
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* memory_block->state_mutex.
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*/
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zone = page_zone(pfn_to_page(pfn));
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/*
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* If this zone is not populated, then it is not in zonelist.
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* This means the page allocator ignores this zone.
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* So, zonelist must be updated after online.
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*/
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if (!populated_zone(zone))
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need_zonelists_rebuild = 1;
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ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages,
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online_pages_range);
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if (ret) {
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printk(KERN_DEBUG "online_pages %lx at %lx failed\n",
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nr_pages, pfn);
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memory_notify(MEM_CANCEL_ONLINE, &arg);
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return ret;
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}
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zone->present_pages += onlined_pages;
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zone->zone_pgdat->node_present_pages += onlined_pages;
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zone_pcp_update(zone);
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setup_per_zone_wmarks();
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calculate_zone_inactive_ratio(zone);
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if (onlined_pages) {
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kswapd_run(zone_to_nid(zone));
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node_set_state(zone_to_nid(zone), N_HIGH_MEMORY);
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}
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if (need_zonelists_rebuild)
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build_all_zonelists();
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else
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vm_total_pages = nr_free_pagecache_pages();
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writeback_set_ratelimit();
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if (onlined_pages)
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memory_notify(MEM_ONLINE, &arg);
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return 0;
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}
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#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
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static pg_data_t *hotadd_new_pgdat(int nid, u64 start)
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{
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struct pglist_data *pgdat;
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unsigned long zones_size[MAX_NR_ZONES] = {0};
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unsigned long zholes_size[MAX_NR_ZONES] = {0};
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unsigned long start_pfn = start >> PAGE_SHIFT;
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pgdat = arch_alloc_nodedata(nid);
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if (!pgdat)
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return NULL;
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arch_refresh_nodedata(nid, pgdat);
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/* we can use NODE_DATA(nid) from here */
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/* init node's zones as empty zones, we don't have any present pages.*/
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free_area_init_node(nid, zones_size, start_pfn, zholes_size);
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return pgdat;
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}
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static void rollback_node_hotadd(int nid, pg_data_t *pgdat)
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{
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arch_refresh_nodedata(nid, NULL);
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arch_free_nodedata(pgdat);
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return;
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}
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/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
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int __ref add_memory(int nid, u64 start, u64 size)
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{
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pg_data_t *pgdat = NULL;
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int new_pgdat = 0;
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struct resource *res;
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int ret;
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res = register_memory_resource(start, size);
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if (!res)
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return -EEXIST;
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if (!node_online(nid)) {
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pgdat = hotadd_new_pgdat(nid, start);
|
|
if (!pgdat)
|
|
return -ENOMEM;
|
|
new_pgdat = 1;
|
|
}
|
|
|
|
/* call arch's memory hotadd */
|
|
ret = arch_add_memory(nid, start, size);
|
|
|
|
if (ret < 0)
|
|
goto error;
|
|
|
|
/* we online node here. we can't roll back from here. */
|
|
node_set_online(nid);
|
|
|
|
if (new_pgdat) {
|
|
ret = register_one_node(nid);
|
|
/*
|
|
* If sysfs file of new node can't create, cpu on the node
|
|
* can't be hot-added. There is no rollback way now.
|
|
* So, check by BUG_ON() to catch it reluctantly..
|
|
*/
|
|
BUG_ON(ret);
|
|
}
|
|
|
|
return ret;
|
|
error:
|
|
/* rollback pgdat allocation and others */
|
|
if (new_pgdat)
|
|
rollback_node_hotadd(nid, pgdat);
|
|
if (res)
|
|
release_memory_resource(res);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(add_memory);
|
|
|
|
#ifdef CONFIG_MEMORY_HOTREMOVE
|
|
/*
|
|
* A free page on the buddy free lists (not the per-cpu lists) has PageBuddy
|
|
* set and the size of the free page is given by page_order(). Using this,
|
|
* the function determines if the pageblock contains only free pages.
|
|
* Due to buddy contraints, a free page at least the size of a pageblock will
|
|
* be located at the start of the pageblock
|
|
*/
|
|
static inline int pageblock_free(struct page *page)
|
|
{
|
|
return PageBuddy(page) && page_order(page) >= pageblock_order;
|
|
}
|
|
|
|
/* Return the start of the next active pageblock after a given page */
|
|
static struct page *next_active_pageblock(struct page *page)
|
|
{
|
|
int pageblocks_stride;
|
|
|
|
/* Ensure the starting page is pageblock-aligned */
|
|
BUG_ON(page_to_pfn(page) & (pageblock_nr_pages - 1));
|
|
|
|
/* Move forward by at least 1 * pageblock_nr_pages */
|
|
pageblocks_stride = 1;
|
|
|
|
/* If the entire pageblock is free, move to the end of free page */
|
|
if (pageblock_free(page))
|
|
pageblocks_stride += page_order(page) - pageblock_order;
|
|
|
|
return page + (pageblocks_stride * pageblock_nr_pages);
|
|
}
|
|
|
|
/* Checks if this range of memory is likely to be hot-removable. */
|
|
int is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages)
|
|
{
|
|
int type;
|
|
struct page *page = pfn_to_page(start_pfn);
|
|
struct page *end_page = page + nr_pages;
|
|
|
|
/* Check the starting page of each pageblock within the range */
|
|
for (; page < end_page; page = next_active_pageblock(page)) {
|
|
type = get_pageblock_migratetype(page);
|
|
|
|
/*
|
|
* A pageblock containing MOVABLE or free pages is considered
|
|
* removable
|
|
*/
|
|
if (type != MIGRATE_MOVABLE && !pageblock_free(page))
|
|
return 0;
|
|
|
|
/*
|
|
* A pageblock starting with a PageReserved page is not
|
|
* considered removable.
|
|
*/
|
|
if (PageReserved(page))
|
|
return 0;
|
|
}
|
|
|
|
/* All pageblocks in the memory block are likely to be hot-removable */
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Confirm all pages in a range [start, end) is belongs to the same zone.
|
|
*/
|
|
static int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn)
|
|
{
|
|
unsigned long pfn;
|
|
struct zone *zone = NULL;
|
|
struct page *page;
|
|
int i;
|
|
for (pfn = start_pfn;
|
|
pfn < end_pfn;
|
|
pfn += MAX_ORDER_NR_PAGES) {
|
|
i = 0;
|
|
/* This is just a CONFIG_HOLES_IN_ZONE check.*/
|
|
while ((i < MAX_ORDER_NR_PAGES) && !pfn_valid_within(pfn + i))
|
|
i++;
|
|
if (i == MAX_ORDER_NR_PAGES)
|
|
continue;
|
|
page = pfn_to_page(pfn + i);
|
|
if (zone && page_zone(page) != zone)
|
|
return 0;
|
|
zone = page_zone(page);
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Scanning pfn is much easier than scanning lru list.
|
|
* Scan pfn from start to end and Find LRU page.
|
|
*/
|
|
int scan_lru_pages(unsigned long start, unsigned long end)
|
|
{
|
|
unsigned long pfn;
|
|
struct page *page;
|
|
for (pfn = start; pfn < end; pfn++) {
|
|
if (pfn_valid(pfn)) {
|
|
page = pfn_to_page(pfn);
|
|
if (PageLRU(page))
|
|
return pfn;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static struct page *
|
|
hotremove_migrate_alloc(struct page *page, unsigned long private, int **x)
|
|
{
|
|
/* This should be improooooved!! */
|
|
return alloc_page(GFP_HIGHUSER_MOVABLE);
|
|
}
|
|
|
|
#define NR_OFFLINE_AT_ONCE_PAGES (256)
|
|
static int
|
|
do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
|
|
{
|
|
unsigned long pfn;
|
|
struct page *page;
|
|
int move_pages = NR_OFFLINE_AT_ONCE_PAGES;
|
|
int not_managed = 0;
|
|
int ret = 0;
|
|
LIST_HEAD(source);
|
|
|
|
for (pfn = start_pfn; pfn < end_pfn && move_pages > 0; pfn++) {
|
|
if (!pfn_valid(pfn))
|
|
continue;
|
|
page = pfn_to_page(pfn);
|
|
if (!page_count(page))
|
|
continue;
|
|
/*
|
|
* We can skip free pages. And we can only deal with pages on
|
|
* LRU.
|
|
*/
|
|
ret = isolate_lru_page(page);
|
|
if (!ret) { /* Success */
|
|
list_add_tail(&page->lru, &source);
|
|
move_pages--;
|
|
} else {
|
|
/* Becasue we don't have big zone->lock. we should
|
|
check this again here. */
|
|
if (page_count(page))
|
|
not_managed++;
|
|
#ifdef CONFIG_DEBUG_VM
|
|
printk(KERN_INFO "removing from LRU failed"
|
|
" %lx/%d/%lx\n",
|
|
pfn, page_count(page), page->flags);
|
|
#endif
|
|
}
|
|
}
|
|
ret = -EBUSY;
|
|
if (not_managed) {
|
|
if (!list_empty(&source))
|
|
putback_lru_pages(&source);
|
|
goto out;
|
|
}
|
|
ret = 0;
|
|
if (list_empty(&source))
|
|
goto out;
|
|
/* this function returns # of failed pages */
|
|
ret = migrate_pages(&source, hotremove_migrate_alloc, 0);
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* remove from free_area[] and mark all as Reserved.
|
|
*/
|
|
static int
|
|
offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages,
|
|
void *data)
|
|
{
|
|
__offline_isolated_pages(start, start + nr_pages);
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
|
|
{
|
|
walk_system_ram_range(start_pfn, end_pfn - start_pfn, NULL,
|
|
offline_isolated_pages_cb);
|
|
}
|
|
|
|
/*
|
|
* Check all pages in range, recoreded as memory resource, are isolated.
|
|
*/
|
|
static int
|
|
check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages,
|
|
void *data)
|
|
{
|
|
int ret;
|
|
long offlined = *(long *)data;
|
|
ret = test_pages_isolated(start_pfn, start_pfn + nr_pages);
|
|
offlined = nr_pages;
|
|
if (!ret)
|
|
*(long *)data += offlined;
|
|
return ret;
|
|
}
|
|
|
|
static long
|
|
check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
|
|
{
|
|
long offlined = 0;
|
|
int ret;
|
|
|
|
ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn, &offlined,
|
|
check_pages_isolated_cb);
|
|
if (ret < 0)
|
|
offlined = (long)ret;
|
|
return offlined;
|
|
}
|
|
|
|
int offline_pages(unsigned long start_pfn,
|
|
unsigned long end_pfn, unsigned long timeout)
|
|
{
|
|
unsigned long pfn, nr_pages, expire;
|
|
long offlined_pages;
|
|
int ret, drain, retry_max, node;
|
|
struct zone *zone;
|
|
struct memory_notify arg;
|
|
|
|
BUG_ON(start_pfn >= end_pfn);
|
|
/* at least, alignment against pageblock is necessary */
|
|
if (!IS_ALIGNED(start_pfn, pageblock_nr_pages))
|
|
return -EINVAL;
|
|
if (!IS_ALIGNED(end_pfn, pageblock_nr_pages))
|
|
return -EINVAL;
|
|
/* This makes hotplug much easier...and readable.
|
|
we assume this for now. .*/
|
|
if (!test_pages_in_a_zone(start_pfn, end_pfn))
|
|
return -EINVAL;
|
|
|
|
zone = page_zone(pfn_to_page(start_pfn));
|
|
node = zone_to_nid(zone);
|
|
nr_pages = end_pfn - start_pfn;
|
|
|
|
/* set above range as isolated */
|
|
ret = start_isolate_page_range(start_pfn, end_pfn);
|
|
if (ret)
|
|
return ret;
|
|
|
|
arg.start_pfn = start_pfn;
|
|
arg.nr_pages = nr_pages;
|
|
arg.status_change_nid = -1;
|
|
if (nr_pages >= node_present_pages(node))
|
|
arg.status_change_nid = node;
|
|
|
|
ret = memory_notify(MEM_GOING_OFFLINE, &arg);
|
|
ret = notifier_to_errno(ret);
|
|
if (ret)
|
|
goto failed_removal;
|
|
|
|
pfn = start_pfn;
|
|
expire = jiffies + timeout;
|
|
drain = 0;
|
|
retry_max = 5;
|
|
repeat:
|
|
/* start memory hot removal */
|
|
ret = -EAGAIN;
|
|
if (time_after(jiffies, expire))
|
|
goto failed_removal;
|
|
ret = -EINTR;
|
|
if (signal_pending(current))
|
|
goto failed_removal;
|
|
ret = 0;
|
|
if (drain) {
|
|
lru_add_drain_all();
|
|
flush_scheduled_work();
|
|
cond_resched();
|
|
drain_all_pages();
|
|
}
|
|
|
|
pfn = scan_lru_pages(start_pfn, end_pfn);
|
|
if (pfn) { /* We have page on LRU */
|
|
ret = do_migrate_range(pfn, end_pfn);
|
|
if (!ret) {
|
|
drain = 1;
|
|
goto repeat;
|
|
} else {
|
|
if (ret < 0)
|
|
if (--retry_max == 0)
|
|
goto failed_removal;
|
|
yield();
|
|
drain = 1;
|
|
goto repeat;
|
|
}
|
|
}
|
|
/* drain all zone's lru pagevec, this is asyncronous... */
|
|
lru_add_drain_all();
|
|
flush_scheduled_work();
|
|
yield();
|
|
/* drain pcp pages , this is synchrouns. */
|
|
drain_all_pages();
|
|
/* check again */
|
|
offlined_pages = check_pages_isolated(start_pfn, end_pfn);
|
|
if (offlined_pages < 0) {
|
|
ret = -EBUSY;
|
|
goto failed_removal;
|
|
}
|
|
printk(KERN_INFO "Offlined Pages %ld\n", offlined_pages);
|
|
/* Ok, all of our target is islaoted.
|
|
We cannot do rollback at this point. */
|
|
offline_isolated_pages(start_pfn, end_pfn);
|
|
/* reset pagetype flags and makes migrate type to be MOVABLE */
|
|
undo_isolate_page_range(start_pfn, end_pfn);
|
|
/* removal success */
|
|
zone->present_pages -= offlined_pages;
|
|
zone->zone_pgdat->node_present_pages -= offlined_pages;
|
|
totalram_pages -= offlined_pages;
|
|
|
|
setup_per_zone_wmarks();
|
|
calculate_zone_inactive_ratio(zone);
|
|
|
|
vm_total_pages = nr_free_pagecache_pages();
|
|
writeback_set_ratelimit();
|
|
|
|
memory_notify(MEM_OFFLINE, &arg);
|
|
return 0;
|
|
|
|
failed_removal:
|
|
printk(KERN_INFO "memory offlining %lx to %lx failed\n",
|
|
start_pfn, end_pfn);
|
|
memory_notify(MEM_CANCEL_OFFLINE, &arg);
|
|
/* pushback to free area */
|
|
undo_isolate_page_range(start_pfn, end_pfn);
|
|
|
|
return ret;
|
|
}
|
|
|
|
int remove_memory(u64 start, u64 size)
|
|
{
|
|
unsigned long start_pfn, end_pfn;
|
|
|
|
start_pfn = PFN_DOWN(start);
|
|
end_pfn = start_pfn + PFN_DOWN(size);
|
|
return offline_pages(start_pfn, end_pfn, 120 * HZ);
|
|
}
|
|
#else
|
|
int remove_memory(u64 start, u64 size)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
#endif /* CONFIG_MEMORY_HOTREMOVE */
|
|
EXPORT_SYMBOL_GPL(remove_memory);
|