#include <linux/highmem.h>
#include <linux/vmalloc.h>
#include <linux/ioport.h>
-#include <linux/cpuset.h>
+#include <linux/delay.h>
+#include <linux/migrate.h>
+#include <linux/page-isolation.h>
+#include <linux/pfn.h>
+#include <linux/suspend.h>
+#include <linux/mm_inline.h>
#include <asm/tlbflush.h>
+#include "internal.h"
+
/* add this memory to iomem resource */
static struct resource *register_memory_resource(u64 start, u64 size)
{
res->name = "System RAM";
res->start = start;
res->end = start + size - 1;
- res->flags = IORESOURCE_MEM;
+ res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
if (request_resource(&iomem_resource, res) < 0) {
printk("System RAM resource %llx - %llx cannot be added\n",
(unsigned long long)res->start, (unsigned long long)res->end);
return;
}
-
#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
-static int __add_zone(struct zone *zone, unsigned long phys_start_pfn)
+#ifndef CONFIG_SPARSEMEM_VMEMMAP
+static void get_page_bootmem(unsigned long info, struct page *page, int type)
+{
+ atomic_set(&page->_mapcount, type);
+ SetPagePrivate(page);
+ set_page_private(page, info);
+ atomic_inc(&page->_count);
+}
+
+/* reference to __meminit __free_pages_bootmem is valid
+ * so use __ref to tell modpost not to generate a warning */
+void __ref put_page_bootmem(struct page *page)
+{
+ int type;
+
+ type = atomic_read(&page->_mapcount);
+ BUG_ON(type >= -1);
+
+ if (atomic_dec_return(&page->_count) == 1) {
+ ClearPagePrivate(page);
+ set_page_private(page, 0);
+ reset_page_mapcount(page);
+ __free_pages_bootmem(page, 0);
+ }
+
+}
+
+static void register_page_bootmem_info_section(unsigned long start_pfn)
+{
+ unsigned long *usemap, mapsize, section_nr, i;
+ struct mem_section *ms;
+ struct page *page, *memmap;
+
+ if (!pfn_valid(start_pfn))
+ return;
+
+ section_nr = pfn_to_section_nr(start_pfn);
+ ms = __nr_to_section(section_nr);
+
+ /* Get section's memmap address */
+ memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
+
+ /*
+ * Get page for the memmap's phys address
+ * XXX: need more consideration for sparse_vmemmap...
+ */
+ page = virt_to_page(memmap);
+ mapsize = sizeof(struct page) * PAGES_PER_SECTION;
+ mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT;
+
+ /* remember memmap's page */
+ for (i = 0; i < mapsize; i++, page++)
+ get_page_bootmem(section_nr, page, SECTION_INFO);
+
+ usemap = __nr_to_section(section_nr)->pageblock_flags;
+ page = virt_to_page(usemap);
+
+ mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT;
+
+ for (i = 0; i < mapsize; i++, page++)
+ get_page_bootmem(section_nr, page, MIX_SECTION_INFO);
+
+}
+
+void register_page_bootmem_info_node(struct pglist_data *pgdat)
+{
+ unsigned long i, pfn, end_pfn, nr_pages;
+ int node = pgdat->node_id;
+ struct page *page;
+ struct zone *zone;
+
+ nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT;
+ page = virt_to_page(pgdat);
+
+ for (i = 0; i < nr_pages; i++, page++)
+ get_page_bootmem(node, page, NODE_INFO);
+
+ zone = &pgdat->node_zones[0];
+ for (; zone < pgdat->node_zones + MAX_NR_ZONES - 1; zone++) {
+ if (zone->wait_table) {
+ nr_pages = zone->wait_table_hash_nr_entries
+ * sizeof(wait_queue_head_t);
+ nr_pages = PAGE_ALIGN(nr_pages) >> PAGE_SHIFT;
+ page = virt_to_page(zone->wait_table);
+
+ for (i = 0; i < nr_pages; i++, page++)
+ get_page_bootmem(node, page, NODE_INFO);
+ }
+ }
+
+ pfn = pgdat->node_start_pfn;
+ end_pfn = pfn + pgdat->node_spanned_pages;
+
+ /* register_section info */
+ for (; pfn < end_pfn; pfn += PAGES_PER_SECTION)
+ register_page_bootmem_info_section(pfn);
+
+}
+#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
+
+static void grow_zone_span(struct zone *zone, unsigned long start_pfn,
+ unsigned long end_pfn)
+{
+ unsigned long old_zone_end_pfn;
+
+ zone_span_writelock(zone);
+
+ old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages;
+ if (start_pfn < zone->zone_start_pfn)
+ zone->zone_start_pfn = start_pfn;
+
+ zone->spanned_pages = max(old_zone_end_pfn, end_pfn) -
+ zone->zone_start_pfn;
+
+ zone_span_writeunlock(zone);
+}
+
+static void grow_pgdat_span(struct pglist_data *pgdat, unsigned long start_pfn,
+ unsigned long end_pfn)
+{
+ unsigned long old_pgdat_end_pfn =
+ pgdat->node_start_pfn + pgdat->node_spanned_pages;
+
+ if (start_pfn < pgdat->node_start_pfn)
+ pgdat->node_start_pfn = start_pfn;
+
+ pgdat->node_spanned_pages = max(old_pgdat_end_pfn, end_pfn) -
+ pgdat->node_start_pfn;
+}
+
+static int __meminit __add_zone(struct zone *zone, unsigned long phys_start_pfn)
{
struct pglist_data *pgdat = zone->zone_pgdat;
int nr_pages = PAGES_PER_SECTION;
int nid = pgdat->node_id;
int zone_type;
+ unsigned long flags;
zone_type = zone - pgdat->node_zones;
if (!zone->wait_table) {
- int ret = 0;
+ int ret;
+
ret = init_currently_empty_zone(zone, phys_start_pfn,
nr_pages, MEMMAP_HOTPLUG);
- if (ret < 0)
+ if (ret)
return ret;
}
+ pgdat_resize_lock(zone->zone_pgdat, &flags);
+ grow_zone_span(zone, phys_start_pfn, phys_start_pfn + nr_pages);
+ grow_pgdat_span(zone->zone_pgdat, phys_start_pfn,
+ phys_start_pfn + nr_pages);
+ pgdat_resize_unlock(zone->zone_pgdat, &flags);
memmap_init_zone(nr_pages, nid, zone_type,
phys_start_pfn, MEMMAP_HOTPLUG);
return 0;
}
-static int __add_section(struct zone *zone, unsigned long phys_start_pfn)
+static int __meminit __add_section(int nid, struct zone *zone,
+ unsigned long phys_start_pfn)
{
int nr_pages = PAGES_PER_SECTION;
int ret;
if (ret < 0)
return ret;
- return register_new_memory(__pfn_to_section(phys_start_pfn));
+ return register_new_memory(nid, __pfn_to_section(phys_start_pfn));
+}
+
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+static int __remove_section(struct zone *zone, struct mem_section *ms)
+{
+ /*
+ * XXX: Freeing memmap with vmemmap is not implement yet.
+ * This should be removed later.
+ */
+ return -EBUSY;
+}
+#else
+static int __remove_section(struct zone *zone, struct mem_section *ms)
+{
+ unsigned long flags;
+ struct pglist_data *pgdat = zone->zone_pgdat;
+ int ret = -EINVAL;
+
+ if (!valid_section(ms))
+ return ret;
+
+ ret = unregister_memory_section(ms);
+ if (ret)
+ return ret;
+
+ pgdat_resize_lock(pgdat, &flags);
+ sparse_remove_one_section(zone, ms);
+ pgdat_resize_unlock(pgdat, &flags);
+ return 0;
}
+#endif
/*
* Reasonably generic function for adding memory. It is
* call this function after deciding the zone to which to
* add the new pages.
*/
-int __add_pages(struct zone *zone, unsigned long phys_start_pfn,
- unsigned long nr_pages)
+int __ref __add_pages(int nid, struct zone *zone, unsigned long phys_start_pfn,
+ unsigned long nr_pages)
{
unsigned long i;
int err = 0;
end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1);
for (i = start_sec; i <= end_sec; i++) {
- err = __add_section(zone, i << PFN_SECTION_SHIFT);
+ err = __add_section(nid, zone, i << PFN_SECTION_SHIFT);
/*
- * EEXIST is finally dealed with by ioresource collision
+ * EEXIST is finally dealt with by ioresource collision
* check. see add_memory() => register_memory_resource()
* Warning will be printed if there is collision.
*/
}
EXPORT_SYMBOL_GPL(__add_pages);
-static void grow_zone_span(struct zone *zone,
- unsigned long start_pfn, unsigned long end_pfn)
+/**
+ * __remove_pages() - remove sections of pages from a zone
+ * @zone: zone from which pages need to be removed
+ * @phys_start_pfn: starting pageframe (must be aligned to start of a section)
+ * @nr_pages: number of pages to remove (must be multiple of section size)
+ *
+ * Generic helper function to remove section mappings and sysfs entries
+ * for the section of the memory we are removing. Caller needs to make
+ * sure that pages are marked reserved and zones are adjust properly by
+ * calling offline_pages().
+ */
+int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
+ unsigned long nr_pages)
{
- unsigned long old_zone_end_pfn;
+ unsigned long i, ret = 0;
+ int sections_to_remove;
- zone_span_writelock(zone);
+ /*
+ * We can only remove entire sections
+ */
+ BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK);
+ BUG_ON(nr_pages % PAGES_PER_SECTION);
+
+ sections_to_remove = nr_pages / PAGES_PER_SECTION;
+ for (i = 0; i < sections_to_remove; i++) {
+ unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION;
+ release_mem_region(pfn << PAGE_SHIFT,
+ PAGES_PER_SECTION << PAGE_SHIFT);
+ ret = __remove_section(zone, __pfn_to_section(pfn));
+ if (ret)
+ break;
+ }
+ return ret;
+}
+EXPORT_SYMBOL_GPL(__remove_pages);
- old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages;
- if (start_pfn < zone->zone_start_pfn)
- zone->zone_start_pfn = start_pfn;
+void online_page(struct page *page)
+{
+ unsigned long pfn = page_to_pfn(page);
- zone->spanned_pages = max(old_zone_end_pfn, end_pfn) -
- zone->zone_start_pfn;
+ totalram_pages++;
+ if (pfn >= num_physpages)
+ num_physpages = pfn + 1;
- zone_span_writeunlock(zone);
-}
+#ifdef CONFIG_HIGHMEM
+ if (PageHighMem(page))
+ totalhigh_pages++;
+#endif
-static void grow_pgdat_span(struct pglist_data *pgdat,
- unsigned long start_pfn, unsigned long end_pfn)
-{
- unsigned long old_pgdat_end_pfn =
- pgdat->node_start_pfn + pgdat->node_spanned_pages;
+#ifdef CONFIG_FLATMEM
+ max_mapnr = max(page_to_pfn(page), max_mapnr);
+#endif
- if (start_pfn < pgdat->node_start_pfn)
- pgdat->node_start_pfn = start_pfn;
+ ClearPageReserved(page);
+ init_page_count(page);
+ __free_page(page);
+}
- pgdat->node_spanned_pages = max(old_pgdat_end_pfn, end_pfn) -
- pgdat->node_start_pfn;
+static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
+ void *arg)
+{
+ unsigned long i;
+ unsigned long onlined_pages = *(unsigned long *)arg;
+ struct page *page;
+ if (PageReserved(pfn_to_page(start_pfn)))
+ for (i = 0; i < nr_pages; i++) {
+ page = pfn_to_page(start_pfn + i);
+ online_page(page);
+ onlined_pages++;
+ }
+ *(unsigned long *)arg = onlined_pages;
+ return 0;
}
+
int online_pages(unsigned long pfn, unsigned long nr_pages)
{
- unsigned long i;
- unsigned long flags;
unsigned long onlined_pages = 0;
- struct resource res;
- u64 section_end;
- unsigned long start_pfn;
struct zone *zone;
int need_zonelists_rebuild = 0;
+ int nid;
+ int ret;
+ struct memory_notify arg;
+
+ arg.start_pfn = pfn;
+ arg.nr_pages = nr_pages;
+ arg.status_change_nid = -1;
+
+ nid = page_to_nid(pfn_to_page(pfn));
+ if (node_present_pages(nid) == 0)
+ arg.status_change_nid = nid;
+ ret = memory_notify(MEM_GOING_ONLINE, &arg);
+ ret = notifier_to_errno(ret);
+ if (ret) {
+ memory_notify(MEM_CANCEL_ONLINE, &arg);
+ return ret;
+ }
/*
* This doesn't need a lock to do pfn_to_page().
* The section can't be removed here because of the
- * memory_block->state_sem.
+ * memory_block->state_mutex.
*/
zone = page_zone(pfn_to_page(pfn));
- pgdat_resize_lock(zone->zone_pgdat, &flags);
- grow_zone_span(zone, pfn, pfn + nr_pages);
- grow_pgdat_span(zone->zone_pgdat, pfn, pfn + nr_pages);
- pgdat_resize_unlock(zone->zone_pgdat, &flags);
-
/*
* If this zone is not populated, then it is not in zonelist.
* This means the page allocator ignores this zone.
if (!populated_zone(zone))
need_zonelists_rebuild = 1;
- res.start = (u64)pfn << PAGE_SHIFT;
- res.end = res.start + ((u64)nr_pages << PAGE_SHIFT) - 1;
- res.flags = IORESOURCE_MEM; /* we just need system ram */
- section_end = res.end;
-
- while ((res.start < res.end) && (find_next_system_ram(&res) >= 0)) {
- start_pfn = (unsigned long)(res.start >> PAGE_SHIFT);
- nr_pages = (unsigned long)
- ((res.end + 1 - res.start) >> PAGE_SHIFT);
-
- if (PageReserved(pfn_to_page(start_pfn))) {
- /* this region's page is not onlined now */
- for (i = 0; i < nr_pages; i++) {
- struct page *page = pfn_to_page(start_pfn + i);
- online_page(page);
- onlined_pages++;
- }
- }
-
- res.start = res.end + 1;
- res.end = section_end;
+ ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages,
+ online_pages_range);
+ if (ret) {
+ printk(KERN_DEBUG "online_pages %lx at %lx failed\n",
+ nr_pages, pfn);
+ memory_notify(MEM_CANCEL_ONLINE, &arg);
+ return ret;
}
+
zone->present_pages += onlined_pages;
zone->zone_pgdat->node_present_pages += onlined_pages;
- setup_per_zone_pages_min();
+ zone_pcp_update(zone);
+ setup_per_zone_wmarks();
+ calculate_zone_inactive_ratio(zone);
if (onlined_pages) {
kswapd_run(zone_to_nid(zone));
node_set_state(zone_to_nid(zone), N_HIGH_MEMORY);
if (need_zonelists_rebuild)
build_all_zonelists();
- vm_total_pages = nr_free_pagecache_pages();
+ else
+ vm_total_pages = nr_free_pagecache_pages();
+
writeback_set_ratelimit();
+
+ if (onlined_pages)
+ memory_notify(MEM_ONLINE, &arg);
+
return 0;
}
#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
-static pg_data_t *hotadd_new_pgdat(int nid, u64 start)
+/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
+static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
{
struct pglist_data *pgdat;
unsigned long zones_size[MAX_NR_ZONES] = {0};
/* we can use NODE_DATA(nid) from here */
/* init node's zones as empty zones, we don't have any present pages.*/
- free_area_init_node(nid, pgdat, zones_size, start_pfn, zholes_size);
+ free_area_init_node(nid, zones_size, start_pfn, zholes_size);
return pgdat;
}
}
-int add_memory(int nid, u64 start, u64 size)
+/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
+int __ref add_memory(int nid, u64 start, u64 size)
{
pg_data_t *pgdat = NULL;
int new_pgdat = 0;
struct resource *res;
int ret;
+ lock_system_sleep();
+
res = register_memory_resource(start, size);
+ ret = -EEXIST;
if (!res)
- return -EEXIST;
+ goto out;
if (!node_online(nid)) {
pgdat = hotadd_new_pgdat(nid, start);
+ ret = -ENOMEM;
if (!pgdat)
- return -ENOMEM;
+ goto out;
new_pgdat = 1;
}
/* we online node here. we can't roll back from here. */
node_set_online(nid);
- cpuset_track_online_nodes();
-
if (new_pgdat) {
ret = register_one_node(nid);
/*
BUG_ON(ret);
}
- return ret;
+ goto out;
+
error:
/* rollback pgdat allocation and others */
if (new_pgdat)
if (res)
release_memory_resource(res);
+out:
+ unlock_system_sleep();
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--;
+ inc_zone_page_state(page, NR_ISOLATED_ANON +
+ page_is_file_cache(page));
+
+ } 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, 1);
+
+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;
+}
+
+static 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;
+
+ lock_system_sleep();
+
+ 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)
+ goto out;
+
+ 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);
+ if (!node_present_pages(node)) {
+ node_clear_state(node, N_HIGH_MEMORY);
+ kswapd_stop(node);
+ }
+
+ vm_total_pages = nr_free_pagecache_pages();
+ writeback_set_ratelimit();
+
+ memory_notify(MEM_OFFLINE, &arg);
+ unlock_system_sleep();
+ 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);
+
+out:
+ unlock_system_sleep();
+ 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);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff