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[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>
This commit is contained in:
KAMEZAWA Hiroyuki 2006-06-27 02:53:36 -07:00 committed by Linus Torvalds
parent 0a54703904
commit 2842f11419
3 changed files with 65 additions and 4 deletions
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3
include/linux/ioport.h
View File

@ -105,6 +105,9 @@ extern int allocate_resource(struct resource *root, struct resource *new,
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))

38
kernel/resource.c
View File

@ -232,6 +232,44 @@ int release_resource(struct resource *old)
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.
*/

22
mm/memory_hotplug.c
View File

@ -127,6 +127,9 @@ 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;
@ -149,11 +152,28 @@ int online_pages(unsigned long pfn, unsigned long nr_pages)
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 (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(pfn + 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;