[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/include/linux/ioport.h b/include/linux/ioport.h
index cd6bd00..edfc733 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -105,6 +105,9 @@
int adjust_resource(struct resource *res, unsigned long start,
unsigned long size);
+/* get registered SYSTEM_RAM resources in specified area */
+extern int find_next_system_ram(struct resource *res);
+
/* Convenience shorthand with allocation */
#define request_region(start,n,name) __request_region(&ioport_resource, (start), (n), (name))
#define request_mem_region(start,n,name) __request_region(&iomem_resource, (start), (n), (name))
diff --git a/kernel/resource.c b/kernel/resource.c
index e3080fc..2404f9b 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -232,6 +232,44 @@
EXPORT_SYMBOL(release_resource);
+#ifdef CONFIG_MEMORY_HOTPLUG
+/*
+ * Finds the lowest memory reosurce exists within [res->start.res->end)
+ * the caller must specify res->start, res->end, res->flags.
+ * If found, returns 0, res is overwritten, if not found, returns -1.
+ */
+int find_next_system_ram(struct resource *res)
+{
+ resource_size_t start, end;
+ struct resource *p;
+
+ BUG_ON(!res);
+
+ start = res->start;
+ end = res->end;
+
+ read_lock(&resource_lock);
+ for (p = iomem_resource.child; p ; p = p->sibling) {
+ /* system ram is just marked as IORESOURCE_MEM */
+ if (p->flags != res->flags)
+ continue;
+ if (p->start > end) {
+ p = NULL;
+ break;
+ }
+ if (p->start >= start)
+ break;
+ }
+ read_unlock(&resource_lock);
+ if (!p)
+ return -1;
+ /* copy data */
+ res->start = p->start;
+ res->end = p->end;
+ return 0;
+}
+#endif
+
/*
* Find empty slot in the resource tree given range and alignment.
*/
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;
