Commit 56bbd65d authored by Christoph Lameter's avatar Christoph Lameter Committed by Linus Torvalds
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Memoryless nodes: Update memory policy and page migration

Online nodes now may have no memory.  The checks and initialization must
therefore be changed to no longer use the online functions.

This will correctly initialize the interleave on bootup to only target nodes
with memory and will make sys_move_pages return an error when a page is to be
moved to a memoryless node.  Similarly we will get an error if MPOL_BIND and
MPOL_INTERLEAVE is used on a memoryless node.

These are somewhat new semantics.  So far one could specify memoryless nodes
and we would maybe do the right thing and just ignore the node (or we'd do
something strange like with MPOL_INTERLEAVE).  If we want to allow the
specification of memoryless nodes via memory policies then we need to keep
checking for online nodes.
Signed-off-by: default avatarChristoph Lameter <>
Acked-by: default avatarNishanth Aravamudan <>
Tested-by: default avatarLee Schermerhorn <>
Acked-by: default avatarBob Picco <>
Cc: KAMEZAWA Hiroyuki <>
Cc: Mel Gorman <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent 4199cfa0
......@@ -494,9 +494,9 @@ static void get_zonemask(struct mempolicy *p, nodemask_t *nodes)
*nodes = p->v.nodes;
/* or use current node instead of online map? */
/* or use current node instead of memory_map? */
if (p->v.preferred_node < 0)
*nodes = node_online_map;
*nodes = node_states[N_HIGH_MEMORY];
node_set(p->v.preferred_node, *nodes);
......@@ -1687,7 +1687,7 @@ void __init numa_policy_init(void)
* fall back to the largest node if they're all smaller.
for_each_online_node(nid) {
for_each_node_state(nid, N_HIGH_MEMORY) {
unsigned long total_pages = node_present_pages(nid);
/* Preserve the largest node */
......@@ -1973,7 +1973,7 @@ int show_numa_map(struct seq_file *m, void *v)
seq_printf(m, " huge");
} else {
check_pgd_range(vma, vma->vm_start, vma->vm_end,
&node_online_map, MPOL_MF_STATS, md);
&node_states[N_HIGH_MEMORY], MPOL_MF_STATS, md);
if (!md->pages)
......@@ -2000,7 +2000,7 @@ int show_numa_map(struct seq_file *m, void *v)
if (md->writeback)
seq_printf(m," writeback=%lu", md->writeback);
for_each_node_state(n, N_HIGH_MEMORY)
if (md->node[n])
seq_printf(m, " N%d=%lu", n, md->node[n]);
......@@ -986,7 +986,7 @@ asmlinkage long sys_move_pages(pid_t pid, unsigned long nr_pages,
goto out;
err = -ENODEV;
if (!node_online(node))
if (!node_state(node, N_HIGH_MEMORY))
goto out;
err = -EACCES;
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