#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 <asm/tlbflush.h>
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);
err = __add_section(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.
*/
pgdat->node_start_pfn;
}
-int online_pages(unsigned long pfn, unsigned long nr_pages)
+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 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
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;
- }
+ 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;
}
#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
if (!pgdat)
return -ENOMEM;
new_pgdat = 1;
- ret = kswapd_run(nid);
- if (ret)
- goto error;
}
/* call arch's memory hotadd */
return ret;
}
EXPORT_SYMBOL_GPL(add_memory);
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+/*
+ * 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 improoooooved!! */
+ return alloc_page(GFP_HIGHUSER_PAGECACHE);
+}
+
+
+#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, &source);
+ if (!ret) { /* Success */
+ 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_memory_resource(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_memory_resource(start_pfn, end_pfn - start_pfn, &offlined,
+ check_pages_isolated_cb);
+ if (ret < 0)
+ offlined = (long)ret;
+ return offlined;
+}
+
+extern void drain_all_local_pages(void);
+
+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_local_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_local_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;
+ num_physpages -= offlined_pages;
+
+ 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;
+}
+#else
+int remove_memory(u64 start, u64 size)
+{
+ return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(remove_memory);
+#endif /* CONFIG_MEMORY_HOTREMOVE */
git.openpandora.org / pandora-kernel.git / blobdiff