[PATCH] catch valid mem range at onlining memory
This patch allows hot-add memory which is not aligned to section.
Now, hot-added memory has to be aligned to section size. Considering big
section sized archs, this is not useful.
When hot-added memory is registerd as iomem resoruce by iomem resource
patch, we can make use of that information to detect valid memory range.
Note: With this, not-aligned memory can be registerd. To allow hot-add
memory with holes, we have to do more work around add_memory().
(It doesn't allows add memory to already existing mem section.)
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 0b11a85..f13783e 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -127,6 +127,9 @@
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;
@@ -149,10 +152,27 @@
if (!populated_zone(zone))
need_zonelists_rebuild = 1;
- for (i = 0; i < nr_pages; i++) {
- struct page *page = pfn_to_page(pfn + i);
- online_page(page);
- onlined_pages++;
+ 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 (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;