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Commit 9ae49fab authored by David Rientjes's avatar David Rientjes Committed by Linus Torvalds
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mm: slab-allocate memory section nodemask for large systems 



Nodemasks should not be allocated on the stack for large systems (when it
is larger than 256 bytes) since there is a threat of overflow.

This patch causes the unregister_mem_sect_under_nodes() nodemask to be
allocated on the stack for smaller systems and be allocated by slab for
larger systems.

GFP_KERNEL is used since remove_memory_block() can block.

Cc: Gary Hade <garyhade@us.ibm.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Alex Chiang <achiang@hp.com>
Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent caed0f48

drivers/base/node.c

+9 −4
Original line number Diff line number Diff line
@@ -363,12 +363,16 @@ int register_mem_sect_under_node(struct memory_block *mem_blk, int nid) 
/* unregister memory section under all nodes that it spans */

int unregister_mem_sect_under_nodes(struct memory_block *mem_blk)

{

	nodemask_t unlinked_nodes;

	NODEMASK_ALLOC(nodemask_t, unlinked_nodes, GFP_KERNEL);

	unsigned long pfn, sect_start_pfn, sect_end_pfn;



	if (!mem_blk)

	if (!mem_blk) {

		NODEMASK_FREE(unlinked_nodes);

		return -EFAULT;

	nodes_clear(unlinked_nodes);

	}

	if (!unlinked_nodes)

		return -ENOMEM;

	nodes_clear(*unlinked_nodes);

	sect_start_pfn = section_nr_to_pfn(mem_blk->phys_index);

	sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;

	for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
@@ -379,13 +383,14 @@ int unregister_mem_sect_under_nodes(struct memory_block *mem_blk) 
			continue;

		if (!node_online(nid))

			continue;

		if (node_test_and_set(nid, unlinked_nodes))

		if (node_test_and_set(nid, *unlinked_nodes))

			continue;

		sysfs_remove_link(&node_devices[nid].sysdev.kobj,

			 kobject_name(&mem_blk->sysdev.kobj));

		sysfs_remove_link(&mem_blk->sysdev.kobj,

			 kobject_name(&node_devices[nid].sysdev.kobj));

	}

	NODEMASK_FREE(unlinked_nodes);

	return 0;

}