linux/mm/memory_hotplug.c
Christoph Lameter 7ea1530ab3 Memoryless nodes: introduce mask of nodes with memory
It is necessary to know if nodes have memory since we have recently begun to
add support for memoryless nodes.  For that purpose we introduce a two new
node states: N_HIGH_MEMORY and N_NORMAL_MEMORY.

A node has its bit in N_HIGH_MEMORY set if it has any memory regardless of the
type of mmemory.  If a node has memory then it has at least one zone defined
in its pgdat structure that is located in the pgdat itself.

A node has its bit in N_NORMAL_MEMORY set if it has a lower zone than
ZONE_HIGHMEM.  This means it is possible to allocate memory that is not
subject to kmap.

N_HIGH_MEMORY and N_NORMAL_MEMORY can then be used in various places to insure
that we do the right thing when we encounter a memoryless node.

[akpm@linux-foundation.org: build fix]
[Lee.Schermerhorn@hp.com: update N_HIGH_MEMORY node state for memory hotadd]
[y-goto@jp.fujitsu.com: Fix memory hotplug + sparsemem build]
Signed-off-by: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Acked-by: Bob Picco <bob.picco@hp.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@skynet.ie>
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:58 -07:00

312 lines
7.4 KiB
C

/*
* linux/mm/memory_hotplug.c
*
* Copyright (C)
*/
#include <linux/stddef.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/interrupt.h>
#include <linux/pagemap.h>
#include <linux/bootmem.h>
#include <linux/compiler.h>
#include <linux/module.h>
#include <linux/pagevec.h>
#include <linux/writeback.h>
#include <linux/slab.h>
#include <linux/sysctl.h>
#include <linux/cpu.h>
#include <linux/memory.h>
#include <linux/memory_hotplug.h>
#include <linux/highmem.h>
#include <linux/vmalloc.h>
#include <linux/ioport.h>
#include <linux/cpuset.h>
#include <asm/tlbflush.h>
/* add this memory to iomem resource */
static struct resource *register_memory_resource(u64 start, u64 size)
{
struct resource *res;
res = kzalloc(sizeof(struct resource), GFP_KERNEL);
BUG_ON(!res);
res->name = "System RAM";
res->start = start;
res->end = start + size - 1;
res->flags = IORESOURCE_MEM;
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);
kfree(res);
res = NULL;
}
return res;
}
static void release_memory_resource(struct resource *res)
{
if (!res)
return;
release_resource(res);
kfree(res);
return;
}
#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
static int __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;
zone_type = zone - pgdat->node_zones;
if (!zone->wait_table) {
int ret = 0;
ret = init_currently_empty_zone(zone, phys_start_pfn,
nr_pages, MEMMAP_HOTPLUG);
if (ret < 0)
return ret;
}
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)
{
int nr_pages = PAGES_PER_SECTION;
int ret;
if (pfn_valid(phys_start_pfn))
return -EEXIST;
ret = sparse_add_one_section(zone, phys_start_pfn, nr_pages);
if (ret < 0)
return ret;
ret = __add_zone(zone, phys_start_pfn);
if (ret < 0)
return ret;
return register_new_memory(__pfn_to_section(phys_start_pfn));
}
/*
* Reasonably generic function for adding memory. It is
* expected that archs that support memory hotplug will
* 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)
{
unsigned long i;
int err = 0;
int start_sec, end_sec;
/* during initialize mem_map, align hot-added range to section */
start_sec = pfn_to_section_nr(phys_start_pfn);
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);
/*
* EEXIST is finally dealed with by ioresource collision
* check. see add_memory() => register_memory_resource()
* Warning will be printed if there is collision.
*/
if (err && (err != -EEXIST))
break;
err = 0;
}
return err;
}
EXPORT_SYMBOL_GPL(__add_pages);
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;
}
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;
/*
* 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.
*/
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.
* So, zonelist must be updated after online.
*/
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;
}
zone->present_pages += onlined_pages;
zone->zone_pgdat->node_present_pages += onlined_pages;
setup_per_zone_pages_min();
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();
writeback_set_ratelimit();
return 0;
}
#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
static pg_data_t *hotadd_new_pgdat(int nid, u64 start)
{
struct pglist_data *pgdat;
unsigned long zones_size[MAX_NR_ZONES] = {0};
unsigned long zholes_size[MAX_NR_ZONES] = {0};
unsigned long start_pfn = start >> PAGE_SHIFT;
pgdat = arch_alloc_nodedata(nid);
if (!pgdat)
return NULL;
arch_refresh_nodedata(nid, pgdat);
/* 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);
return pgdat;
}
static void rollback_node_hotadd(int nid, pg_data_t *pgdat)
{
arch_refresh_nodedata(nid, NULL);
arch_free_nodedata(pgdat);
return;
}
int add_memory(int nid, u64 start, u64 size)
{
pg_data_t *pgdat = NULL;
int new_pgdat = 0;
struct resource *res;
int ret;
res = register_memory_resource(start, size);
if (!res)
return -EEXIST;
if (!node_online(nid)) {
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);
cpuset_track_online_nodes();
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);