int online_pages(unsigned long pfn, unsigned long nr_pages)
{
unsigned long flags;
unsigned long onlined_pages = 0;
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.
*/
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;
walk_memory_resource(pfn, nr_pages, &onlined_pages,
online_pages_range);
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();
if (onlined_pages)
memory_notify(MEM_ONLINE, &arg);
return 0;
}
/*
* MEMORY_HOTPLUG depends on SPARSEMEM in mm/Kconfig, so it is
* OK to have direct references to sparsemem variables in here.
*/
static int
memory_block_action(struct memory_block *mem, unsigned long action)
{
int i;
unsigned long psection;
unsigned long start_pfn, start_paddr;
struct page *first_page;
int ret;
int old_state = mem->state;
psection = mem->phys_index;
first_page = pfn_to_page(psection << PFN_SECTION_SHIFT);
/*
* The probe routines leave the pages reserved, just
* as the bootmem code does. Make sure they're still
* that way.
*/
if (action == MEM_ONLINE) {
for (i = 0; i < PAGES_PER_SECTION; i++) {
if (PageReserved(first_page+i))
continue;
printk(KERN_WARNING "section number %ld page number %d "
"not reserved, was it already online? \n",
psection, i);
return -EBUSY;
}
}
switch (action) {
case MEM_ONLINE:
start_pfn = page_to_pfn(first_page);
ret = online_pages(start_pfn, PAGES_PER_SECTION);
break;
case MEM_OFFLINE:
mem->state = MEM_GOING_OFFLINE;
memory_notify(MEM_GOING_OFFLINE, NULL);
start_paddr = page_to_pfn(first_page) << PAGE_SHIFT;
ret = remove_memory(start_paddr,
PAGES_PER_SECTION << PAGE_SHIFT);
if (ret) {
mem->state = old_state;
break;
}
memory_notify(MEM_MAPPING_INVALID, NULL);
break;
default:
printk(KERN_WARNING "%s(%p, %ld) unknown action: %ld\n",
__FUNCTION__, mem, action, action);
WARN_ON(1);
ret = -EINVAL;
}
/*
* For now, only notify on successful memory operations
*/
if (!ret)
memory_notify(action, NULL);
return ret;
}
