Commit 54f23eb7 authored by Nathan Fontenot's avatar Nathan Fontenot Committed by Greg Kroah-Hartman
Browse files

memory hotplug: Correct page reservation checking 



The check to ensure that pages of recently added memory sections are correctly
marked as reserved before trying to online the memory is broken.  The request
to online the memory fails with the following:

kernel: section number XXX page number 256 not reserved, was it already online?

This updates the page reservation checking to check the pages of each memory
section of the memory block being onlined individually.

Signed-off-by: default avatarNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 61b94fea

drivers/base/memory.c

+37 −23
Original line number Diff line number Diff line
@@ -227,41 +227,42 @@ int memory_isolate_notify(unsigned long val, void *v) 
 * MEMORY_HOTPLUG depends on SPARSEMEM in mm/Kconfig, so it is

 * OK to have direct references to sparsemem variables in here.

 */

static int

memory_block_action(unsigned long phys_index, unsigned long action)

static int check_page_reservations(unsigned long phys_index)

{

	int i;

	unsigned long start_pfn, start_paddr;

	unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block;

	struct page *first_page;

	int ret;

	struct page *page;



	first_page = pfn_to_page(phys_index << PFN_SECTION_SHIFT);

	page = pfn_to_page(phys_index << PFN_SECTION_SHIFT);



	/*

	 * The probe routines leave the pages reserved, just

	 * as the bootmem code does.  Make sure they're still

	 * that way.

	 */

	if (action == MEM_ONLINE) {

		for (i = 0; i < nr_pages; i++) {

			if (PageReserved(first_page+i))

	for (i = 0; i < PAGES_PER_SECTION; i++) {

		if (PageReserved(page + i))

			continue;



		printk(KERN_WARNING "section number %ld page number %d "

				"not reserved, was it already online?\n",

				phys_index, i);

			"not reserved, was it already online?\n", phys_index, i);

			return -EBUSY;

	}



	return 0;

}



static int

memory_block_action(unsigned long phys_index, unsigned long action)

{

	unsigned long start_pfn, start_paddr;

	unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block;

	struct page *page;

	int ret;



	page = pfn_to_page(phys_index << PFN_SECTION_SHIFT);



	switch (action) {

		case MEM_ONLINE:

			start_pfn = page_to_pfn(first_page);

			start_pfn = page_to_pfn(page);

			ret = online_pages(start_pfn, nr_pages);

			break;

		case MEM_OFFLINE:

			start_paddr = page_to_pfn(first_page) << PAGE_SHIFT;

			start_paddr = page_to_pfn(page) << PAGE_SHIFT;

			ret = remove_memory(start_paddr,

					    nr_pages << PAGE_SHIFT);

			break;
@@ -277,7 +278,7 @@ memory_block_action(unsigned long phys_index, unsigned long action) 
static int memory_block_change_state(struct memory_block *mem,

		unsigned long to_state, unsigned long from_state_req)

{

	int ret = 0;

	int i, ret = 0;



	mutex_lock(&mem->state_mutex);
@@ -289,6 +290,19 @@ static int memory_block_change_state(struct memory_block *mem, 
	if (to_state == MEM_OFFLINE)

		mem->state = MEM_GOING_OFFLINE;



	if (to_state == MEM_ONLINE) {

		/*

		 * The probe routines leave the pages reserved, just

		 * as the bootmem code does.  Make sure they're still

		 * that way.

		 */

		for (i = 0; i < sections_per_block; i++) {

			ret = check_page_reservations(mem->start_section_nr + i);

			if (ret)

				return ret;

		}

	}



	ret = memory_block_action(mem->start_section_nr, to_state);



	if (ret)

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