Commit 66918dcd authored by Yinghai Lu's avatar Yinghai Lu Committed by Linus Torvalds
Browse files

x86: only clear node_states for 64bit 



Nathan reported that

| commit 73d60b7f
| Author: Yinghai Lu <yinghai@kernel.org>
| Date:   Tue Jun 16 15:33:00 2009 -0700
|
|    page-allocator: clear N_HIGH_MEMORY map before we set it again
|
|    SRAT tables may contains nodes of very small size.  The arch code may
|    decide to not activate such a node.  However, currently the early boot
|    code sets N_HIGH_MEMORY for such nodes.  These nodes therefore seem to be
|    active although these nodes have no present pages.
|
|    For 64bit N_HIGH_MEMORY == N_NORMAL_MEMORY, so that works for 64 bit too

unintentionally and incorrectly clears the cpuset.mems cgroup attribute on
an i386 kvm guest, meaning that cpuset.mems can not be used.

Fix this by only clearing node_states[N_NORMAL_MEMORY] for 64bit only.
and need to do save/restore for that in find_zone_movable_pfn

Reported-by: default avatarNathan Lynch <ntl@pobox.com>
Tested-by: default avatarNathan Lynch <ntl@pobox.com>
Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>,
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b37f2d4d

arch/x86/mm/init_64.c

+2 −0
Original line number Diff line number Diff line
@@ -598,6 +598,8 @@ void __init paging_init(void) 


	sparse_memory_present_with_active_regions(MAX_NUMNODES);

	sparse_init();

	/* clear the default setting with node 0 */

	nodes_clear(node_states[N_NORMAL_MEMORY]);

	free_area_init_nodes(max_zone_pfns);

}

mm/page_alloc.c

+7 −6
Original line number Diff line number Diff line
@@ -4032,6 +4032,8 @@ static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn) 
	int i, nid;

	unsigned long usable_startpfn;

	unsigned long kernelcore_node, kernelcore_remaining;

	/* save the state before borrow the nodemask */

	nodemask_t saved_node_state = node_states[N_HIGH_MEMORY];

	unsigned long totalpages = early_calculate_totalpages();

	int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
@@ -4059,7 +4061,7 @@ static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn) 


	/* If kernelcore was not specified, there is no ZONE_MOVABLE */

	if (!required_kernelcore)

		return;

		goto out;



	/* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */

	find_usable_zone_for_movable();
@@ -4158,6 +4160,10 @@ restart: 
	for (nid = 0; nid < MAX_NUMNODES; nid++)

		zone_movable_pfn[nid] =

			roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);



out:

	/* restore the node_state */

	node_states[N_HIGH_MEMORY] = saved_node_state;

}



/* Any regular memory on that node ? */
@@ -4242,11 +4248,6 @@ void __init free_area_init_nodes(unsigned long *max_zone_pfn) 
						early_node_map[i].start_pfn,

						early_node_map[i].end_pfn);



	/*

	 * find_zone_movable_pfns_for_nodes/early_calculate_totalpages init

	 * that node_mask, clear it at first

	 */

	nodes_clear(node_states[N_HIGH_MEMORY]);

	/* Initialise every node */

	mminit_verify_pageflags_layout();

	setup_nr_node_ids();

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