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Commit 75884fb1 authored by KAMEZAWA Hiroyuki's avatar KAMEZAWA Hiroyuki Committed by Linus Torvalds
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memory unplug: memory hotplug cleanup 



A clean up patch for "scanning memory resource [start, end)" operation.

Now, find_next_system_ram() function is used in memory hotplug, but this
interface is not easy to use and codes are complicated.

This patch adds walk_memory_resouce(start,len,arg,func) function.
The function 'func' is called per valid memory resouce range in [start,pfn).

[pbadari@us.ibm.com: Error handling in walk_memory_resource()]
Signed-off-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: default avatarBadari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 48f13bf3

include/linux/ioport.h

+0 −3
Original line number Diff line number Diff line
@@ -110,9 +110,6 @@ extern int allocate_resource(struct resource *root, struct resource *new, 
int adjust_resource(struct resource *res, resource_size_t start,

		    resource_size_t 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))

include/linux/memory_hotplug.h

+8 −0
Original line number Diff line number Diff line
@@ -63,6 +63,14 @@ extern int online_pages(unsigned long, unsigned long); 
extern int __add_pages(struct zone *zone, unsigned long start_pfn,

	unsigned long nr_pages);



/*

 * Walk thorugh all memory which is registered as resource.

 * arg is (start_pfn, nr_pages, private_arg_pointer)

 */

extern int walk_memory_resource(unsigned long start_pfn,

			unsigned long nr_pages, void *arg,

			int (*func)(unsigned long, unsigned long, void *));



#ifdef CONFIG_NUMA

extern int memory_add_physaddr_to_nid(u64 start);

#else

kernel/resource.c

+25 −1
Original line number Diff line number Diff line
@@ -234,7 +234,7 @@ EXPORT_SYMBOL(release_resource); 
 * 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)

static int find_next_system_ram(struct resource *res)

{

	resource_size_t start, end;

	struct resource *p;
@@ -267,6 +267,30 @@ int find_next_system_ram(struct resource *res) 
		res->end = p->end;

	return 0;

}

int

walk_memory_resource(unsigned long start_pfn, unsigned long nr_pages, void *arg,

			int (*func)(unsigned long, unsigned long, void *))

{

	struct resource res;

	unsigned long pfn, len;

	u64 orig_end;

	int ret = -1;

	res.start = (u64) start_pfn << PAGE_SHIFT;

	res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;

	res.flags = IORESOURCE_MEM;

	orig_end = res.end;

	while ((res.start < res.end) && (find_next_system_ram(&res) >= 0)) {

		pfn = (unsigned long)(res.start >> PAGE_SHIFT);

		len = (unsigned long)((res.end + 1 - res.start) >> PAGE_SHIFT);

		ret = (*func)(pfn, len, arg);

		if (ret)

			break;

		res.start = res.end + 1;

		res.end = orig_end;

	}

	return ret;

}



#endif



/*

mm/memory_hotplug.c

+19 −26
Original line number Diff line number Diff line
@@ -161,14 +161,27 @@ static void grow_pgdat_span(struct pglist_data *pgdat, 
					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;
@@ -191,28 +204,8 @@ 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 ((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;